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Control Implants (control + implant)

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Medical Sciences	86%

Selected Abstracts

Bone formation at recombinant human bone morphogenetic protein-2-coated titanium implants in the posterior maxilla (Type IV bone) in non-human primates

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 11 2008
Ulf M. E. Wikesjö
Abstract Background: Studies using ectopic rodent and orthotopic canine models (Type II bone) have shown that titanium porous oxide (TPO) surface implants adsorbed with recombinant human bone morphogenetic protein-2 (rhBMP-2) induce local bone formation including osseointegration. The objective of this study was to evaluate local bone formation and osseointegration at such implants placed into Type IV bone. Material and Methods: rhBMP-2-coated implants were installed into the edentulated posterior maxilla in eight young adult Cynomolgus monkeys: four animals each received three TPO implants adsorbed with rhBMP-2 (2.0 mg/ml) and four animals each received three TPO implants adsorbed with rhBMP-2 (0.2 mg/ml). Contra-lateral jaw quadrants received three TPO implants without rhBMP-2 (control). Treatments were alternated between left and right jaw quadrants. Mucosal flaps were advanced and sutured to submerge the implants. The animals received fluorescent bone markers at weeks 2, 3, 4, and at week 16 when they were euthanized for histologic analysis. Results: Clinical healing was uneventful. Extensive local bone formation was observed in animals receiving implants adsorbed with rhBMP-2 (2.0 mg/ml). The newly formed bone exhibited a specific pinpoint bone,implant contact pattern regardless of rhBMP-2 concentration resulting in significant osseointegration; rhBMP-2 (2.0 mg/ml): 43% and rhBMP-2 (0.2 mg/ml): 37%. Control implants exhibited a thin layer of bone covering a relatively larger portion of the implant threads. Thus, TPO control implants bone exhibited significantly greater bone,implant contact (,75%; p<0.05). There were no statistically significant differences between rhBMP-2-coated and control implants relative to any other parameter including peri-implant and intra-thread bone density. Conclusion: rhBMP-2-coated TPO implants enhanced/accelerated local bone formation in Type IV bone in a dose-dependent fashion in non-human primates resulting in significant osseointegration. rhBMP-2-induced de novo bone formation did not reach the level of osseointegration observed in native resident bone within the 16-week interval. [source]

Alveolar ridge augmentation using implants coated with recombinant human bone morphogenetic protein-2: histologic observations

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 11 2008
Ulf M. E. Wikesjö
Abstract Background: Studies using ectopic rodent, orthotopic canine, and non-human primate models show that bone morphogenetic proteins (BMPs) coated onto titanium surfaces induce local bone formation. The objective of this study was to examine the ability of recombinant human BMP-2 (rhBMP-2) coated onto a titanium porous oxide implant surface to stimulate local bone formation including osseointegration and vertical augmentation of the alveolar ridge. Material and Methods: Bilateral, critical-size, 5 mm, supra-alveolar, peri-implant defects were created in 12 young adult Hound Labrador mongrel dogs. Six animals received implants coated with rhBMP-2 at 0.75 or 1.5 mg/ml, and six animals received implants coated with rhBMP-2 at 3.0 mg/ml or uncoated control. Treatments were randomized between jaw quadrants. The mucoperiosteal flaps were advanced, adapted and sutured to submerge the implants for primary intention healing. The animals received fluorescent bone markers at weeks 3, 4, 7 and 8 post-surgery when they were euthanized for histologic evaluation. Results: Jaw quadrants receiving implants coated with rhBMP-2 exhibited gradually regressing swelling that became hard to palpate disguising the contours of the implants. The histologic evaluation showed robust bone formation reaching or exceeding the implant platform. The newly formed bone exhibited characteristics of the adjoining resident Type II bone including cortex formation for sites receiving implants coated with rhBMP-2 at 0.75 or 1.5 mg/ml. Sites receiving implants coated with rhBMP-2 at 3.0 mg/ml exhibited more immature trabecular bone formation, seroma formation and peri-implant bone remodelling resulting in undesirable implant displacement. Control implants exhibited minimal, if any, bone formation. Thus, implants coated with rhBMP-2 at 0.75, 1.5 and 3.0 mg/ml exhibited significant bone formation (height and area) compared with the sham-surgery control averaging (±SD) 4.4±0.4, 4.2±0.7 and 4.2±1.2 versus 0.8±0.3 mm; and 5.0±2.2, 5.6±2.2 and 7.4±3.5 versus 0.7±0.3 mm2, respectively (p<0.01). All the treatment groups exhibited clinically relevant osseointegration. Conclusions: rhBMP-2 coated onto titanium porous oxide implant surfaces induced clinically relevant local bone formation including vertical augmentation of the alveolar ridge and osseointegration. Higher concentrations/doses were associated with untoward effects. [source]

Locally delivered rhTGF-,2 enhances bone ingrowth and bone regeneration at local and remote sites of skeletal injury

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 1 2001
Dr. Sumner
The purposes of the present study were to determine if recombinant human transforming growth factor-beta-2 (rhTGF-,2) enhances bone ingrowth into porous-coated implants and bone regeneration in gaps between the implant and surrounding host bone. The implants were placed bilaterally for four weeks in the proximal humeri of skeletally mature, adult male dogs in the presence of a 3-mm gap. In three treatment groups of animals, the test implant was treated with hydroxyapatite/tricalcium phosphate (HA/TCP) and rhTGF-,2 in buffer at a dose per implant of 1.2 ,g (n = 6), 12 ,g (n = 7), or 120 ,g (n = 7) and placed in the left humerus. In these same animals, an internal control implant treated only with HA/TCP and buffer was placed in the right humerus. In a non-TGF-, treated external control group of animals (n = 7), one implant was treated with HA/TCP while the contralateral implant was not treated with the ceramic. In vitro analyses showed that approximately 15% of the applied dose was released within 120 h with most of the release occurring in the first 24 h. The TGF-, treated implants had significantly more bone ingrowth than the controls with the greatest effect in the 12 ,g/implant group (a 2.2-fold increase over the paired internal control (P = 0.004) and a 4-fold increase over the external control (P < 0.001)). The TGF-, treated implants had significantly more bone formation in the gap than the controls with the greatest effect in the 12 and 120 ,g groups (1.8-fold increases over the paired internal controls (P = 0.003 and P = 0.012, respectively) and 2.8-fold increases over the external controls (P < 0.001 and P = 0.001, respectively)). Compared to the external controls, the internal control implants tended to have more bone ingrowth (1.9-fold increase, P = 0.066) and had significantly more bone formation in the gap (1.7-fold increase, P = 0.008). Thus, application of rhTGF-,2 to a porous-coated implant-stimulated local bone ingrowth and gap healing in a weakly dose-dependent manner and stimulated bone regeneration in the 3-mm gap surrounding the contralateral control implant, a site remote from the local treatment with the growth factor. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source]

One-Year Prospective Three-Center Study Comparing the Outcome of a "Soft Bone Implant" (Prototype Mk IV) and the Standard Brånemark Implant

CLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 2 2003
Bertil Friberg DDS
ABSTRACT Background: Oral implant treatment ad modum Brånemark has been used for decades in the rehabilitation of edentate and partially dentate patients. Posterior jaw regions frequently exhibit bone of poor texture, and it is often difficult to obtain primary stability. Thus, it may prove beneficial to deviate from the original protocol and to use implants with a modified design, for example, with a slightly tapered geometry. Purpose: The purpose of the investigation was to compare the early behavior of a modified (prototype Mk IV, Branemark System, Nobel Biocare AB, Gothenburg, Sweden; test) implant with that of the standard Brånemark implant (control) in regions of mainly type 4 bone. Materials and Methods: Three Swedish centers participated, and a total of 44 patients were treated with oral implants for 39 maxillas and 5 mandibles. The study focused on the most distal right and left implant sites (88 implants), which were randomized to receive either a test or a control implant. Various parameters were recorded, such as registered insertion torque (OsseoCare, Nobel Biocare AB), wobbling during insertion, primary and secondary stability (as measured with resonance frequency), and marginal bone loss. The implants were followed up for 1 year. Results.: The test implant more frequently required a higher insertion torque and showed a significantly higher primary stability than the control implant. This difference in stability leveled out over time, and test and control implants exhibited similar secondary stability at abutment operation and at the 1-year visit. Wobbling during insertion was rarely recorded for either of the implant designs. The 1-year cumulative success rate was 93.1% for test implants and 88.4% for control implants. Conclusions: The modified implant design resulted in an increased primary stability, which may be important when placing implants in jaw regions of type 4 bone. However, independent of the achieved primary stability, successful implants tended to approach similar secondary stability in the two designs tested. [source]

Fixed Mandibular Restorations on Three Early-Loaded Regular Platform Brånemark Implants

CLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 4 2001
Hugo De Bruyn DDS
ABSTRACT Background: Originally, the Brånemark System was used as a two-stage surgical procedure. Comparable clinical results have made one-stage and early-loading concepts possible alternatives in the edentulous mandible. From the patient's point of view, the financial aspect of implant treatment is important. In an attempt to decrease financial burden, the reduction of surgical interventions and reduction of the number of implants could be considered. Purpose: This prospective multicenter study evaluated (1) the 1-and 3-year success rates of implants loaded within 1 month after one-stage surgery with a fixed 10- to 12-unit bridge on three regular platform Brånemark System implants in the mandible, (2) the outcome of the prosthetic treatment, and (3) the opinion of patients regarding the treatment procedure. Materials and Methods: Of 20 patients, 19 received five implants in the mandible, of which three were functionally loaded with the one-stage technique (group 1). The loaded implants were inserted in a tripodal position, one implant in the symphysis and two located anterior of the mental foramen in the bicuspid area. Two additional implants were inserted for safety reasons but were not intended to be included in the restoration. These two additional implants served as either an unloaded one-stage control implant (group 2) or an unloaded control implant installed with the submerged technique (group 3). Immediately after surgery, the implants were loaded with a relined denture. The patients received a 10- to 12-unit prosthetic reconstruction an average 31 days (range, 4-53 d) after surgery. Implant stability was clinically checked at 3, 12, and 36 months. Radiographs were taken at corresponding follow-up visits to calculate bone-to-implant level and marginal bone resorption. Results: Six of 60 functionally loaded implants (10%) and 3 of 20 prostheses (15%) failed within the first year. The cumulative implant failure rate in group 1, both after 1 and after 3 years, was 9.5%. No implant failure occurred in the control groups 2 and 3. The average marginal bone level measured at 1 and 3 years was 1.6 mm (SD = 0.8 mm) and 2.1 mm (SD = 0.2 mm), respectively, for group 1; 1.5 mm (SD = 1.3 mm) and 2.4 mm (SD = 0.6 mm), respectively, for group 2; 0.8 mm (SD = 1.4 mm) and 0.7 mm (SD = 0.9 mm), respectively, for group 3. Conclusions: The results of treatment using three regular platform Brånemark System implants supporting a fixed mandibular arch reconstruction were less favorable than the outcome that can be expected with a standard four- to six-implant with one-stage surgery. [source]

Collagen membranes at immediate implants: a histomorphometric study in dogs

CLINICAL ORAL IMPLANTS RESEARCH, Issue 9 2010
Marco Caneva
Abstract Aim: To evaluate the influence of resorbable membranes on hard tissue alterations and osseointegration at implants placed into extraction sockets in a dog model. Material and methods: In the mandibular premolar region, implants were installed immediately into the extraction sockets of six Labrador dogs. Collagen-resorbable membranes were placed at the test sites, while the control sites were left uncovered. Implants were intended to heal in a submerged mode. After 4 months of healing, the animals were sacrificed, and ground sections were obtained for histomorphometric evaluation. Results: After 4 months of healing, a control implant was not integrated (n=5). Both at the test and at the control sites, bone resorption occurred. While the most coronal bone-to-implant contact was similar between the test and the control sites, the alveolar bone crest outline was maintained to a higher degree at the buccal aspect of the test sites (loss: 1.7 mm) compared with the control sites (loss: 2.2 mm). Conclusions: The use of collagen-resorbable membranes at implants immediately placed into extraction sockets contributed to a partial (23%) preservation of the buccal outline of the alveolar process. To cite this article: Caneva M, Botticelli D, Salata LA, Souza SLS, Carvalho Cardoso L, Lang NP. Collagen membranes at immediate implants: a histomorphometric study in dogs. Clin. Oral Impl. Res. 21, 2010; 891,897. doi: 10.1111/j.1600-0501.2010.01946.x [source]

Alveolar ridge augmentation using implants coated with recombinant human growth/differentiation factor-5: histologic observations

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 8 2010
Giuseppe Polimeni
Polimeni G, Wikesjö UME, Susin C, Qahash M, Shanaman RH, Prasad HS, Rohrer MD, Hall J. Alveolar ridge augmentation using implants coated with recombinant human growth/differentiation factor-5: histologic observations. J Clin Periodontol 2010; 37: 759-768 doi: 10.1111/j.1600-051X.2010.01579.x. Abstract Objectives: In vitro and in vivo preclinical studies suggest that growth/differentiation factor-5 (GDF-5) may induce local bone formation. The objective of this study was to evaluate the potential of recombinant human GDF-5 (rhGDF-5) coated onto an oral implant with a purpose-designed titanium porous oxide surface to stimulate local bone formation including osseointegration and vertical augmentation of the alveolar ridge. Materials and Methods: Bilateral, critical-size, 5 mm, supraalveolar peri-implant defects were created in 12 young adult Hound Labrador mongrel dogs. Six animals received implants coated with 30 or 60 ,g rhGDF-5, and six animals received implants coated with 120 ,g rhGDF-5 or left uncoated (control). Treatments were alternated between jaw quadrants. The mucoperiosteal flaps were advanced, adapted, and sutured to submerge the implants for primary intention healing. The animals received fluorescent bone markers at weeks 3, 4, 7, and 8 post-surgery when they were euthanized for histologic evaluation. Results: The clinical examination showed no noteworthy differences between implants coated with rhGDF-5. The cover screw and implant body were visible/palpable through the alveolar mucosa for both rhGDF-5-coated and control implants. There was a small increase in induced bone height for implants coated with rhGDF-5 compared with the control, induced bone height averaging (±SD) 1.6±0.6 mm for implants coated with 120 ,g rhGDF-5 versus 1.2±0.5, 1.2±0.6, and 0.6±0.2 mm for implants coated with 60 ,g rhGDF-5, 30 ,g rhGDF-5, or left uncoated, respectively (p<0.05). Bone formation was predominant at the lingual aspect of the implants. Narrow yellow and orange fluorescent markers throughout the newly formed bone indicate relatively slow new bone formation within 3,4 weeks. Implants coated with rhGDF-5 displayed limited peri-implant bone remodelling in the resident bone; the 120 ,g dose exhibiting more advanced remodelling than the 60 and 30 ,g doses. All treatment groups exhibited clinically relevant osseointegration. Conclusions: rhGDF-5-coated oral implants display a dose-dependent osteoinductive and/or osteoconductive effect, bone formation apparently benefiting from local factors. Application of rhGDF-5 appears to be safe as it is associated with limited, if any, adverse effects. [source]

Bone formation at recombinant human bone morphogenetic protein-2-coated titanium implants in the posterior maxilla (Type IV bone) in non-human primates

Bone reactions to longstanding functional load at implants: an experimental study in dogs

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 9 2005
T. Berglundh
Abstract Objectives: The aims of the present investigation were (i) to study marginal bone level alterations following implant installation, abutment connection and functional loading and (ii) to analyse bone tissue reactions to functional load. Material and Methods: Six beagle dogs, about 1-year old, were used. All mandibular pre-molars were extracted. Three months later four implants of the Astra Tech Implants® Dental System were installed in one side of the mandible and four standard fixtures of the Brånemark System® were placed in the contralateral side of the mandible. Abutment connection was performed 3 months later and a plaque control programme was initiated. Three months after abutment connection fixed partial dentures (FPDs) made in gold were cemented to the maxillary canines and pre-molars. FPDs were also connected to the three posterior implants in each side of the mandible, while the mesial implant in each side was used as an unloaded control. Radiographs were obtained from all implant sites following implant installation, abutment connection and FPD placement. Ten months after the FPD placement the radiographic examination was repeated. The animals were sacrificed and biopsies from all implant sites were obtained and prepared for histological analysis. Results: The radiographic analysis revealed that largest amount of bone loss occurred following implant installation and abutment connection and that this loss was more pronounced at Brånemark than at Astra implants. The bone level alterations that were observed at implants exposed to 10 months of functional load in both implant systems were small and did not differ from control sites. The histological analysis revealed that implants exposed to functional load exhibited a higher degree of bone-to-implant contact than control implants in both implant systems. Conclusion: It is suggested that functional load at implants may enhance osseointegration and does not result in marginal bone loss. [source]

Enamel matrix derivative and titanium implants

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 4 2003
An experimental pilot study in the rabbit
Aim: The aim of present study was to evaluate if an enamel matrix derivative (Emdogain®) may enhance bone formation and osseointegration of titanium implants, using a well-documented rabbit model. Material and methods: Thirty-six threaded commercially pure titanium (cp.ti.) implants were inserted in six New Zealand white rabbits. One implant was placed in each femur and two in each tibia. Prior to implant insertion approximately 0.5 mL of Emdogain (EMD) (test) or the vehicle gel (PGA: propylene glycol alginate) (control) was injected into the surgically prepared implant site. The follow-up time was 6 weeks. Biomechanical evaluations by resonance frequency analysis (RFA) and removal torque measurements (RTQ) were performed. Histomorphometrical quantifications were made on ground sections by measurements of the percentage of bone-to-metal contact, bone area inside the threads as well as outside the threads (mirror image). Bone lengths along the implant surface were also measured and used for shear strength calculations. Results: The results demonstrated no beneficial effects from the EMD treatment on bone formation around titanium implants in any of the tested parameters. Significant differences were demonstrated with removal torque test and shear force calculations for the control implants. No other parameter demonstrated a statistically significant difference. Conclusion: The results of the present study may indicate that EMD does not contribute to bone formation around titanium implants. This observation may indicate that the bone formation that occurs after EMD treatment in periodontal defects is the result of functional adaptation. However, further research is required to evaluate the effect of EMD treatment on bone formation. Zusammenfassung Schmelzmatrixprotein und Titanimplantate. Eine experimentelle Pilotstudie beim Kaninchen Zielsetzung: Untersuchung im gut dokumentierten Kaninchenmodell, ob Schmelzmatrixprotein (Emdogain®) die Knochenbildung und Osseointegration von Titanimplantaten verbessert. Material und Methoden: 36 kommerziell erhältliche Schraubenimplantate aus reinem Titan (cp.ti.) wurden bei 6 weißen Neuseeländischen Kaninchen inseriert. Ein Implantat wurde in jeden Femur und 2 in jede Tibia gesetzt. Vor Implantatinsertion wurden etwa 0,5 ml Emdogain (EMD) (Test) oder das Trägergel (PGA: Propylenglykolalginat) (Kontrolle) in die chirurgisch vorbereitete Insertionsstelle gespritzt. Die Nachuntersuchungszeit betrug 6 Wochen. Die biomechanischen Untersuchungen umfassten eine Resonanzfrequenzanalyse (RFA) und die Messung des Drehmoments, das zur Entfernung der Implantate nötig war (RTQ). Folgende histomorphometrische Messungen wurden auf Schliffpräparaten durchgeführt: Messung des prozentualen Knochen-zu-Metall-Kontaktes, Knochenbereich innerhalb und außerhalb der Schraubengewinde (Spiegelbild). Die Knochenlänge entlang der Implantate wurde ausgemessen und für Scherkraftberechnungen genutzt. Ergebnisse: Es konnten für keinen der untersuchten Parameter günstige Auswirkungen der Anwendung von EMD auf die Knochenbildung um Titanimplantate beobachtet werden. Signifikante Unterschiede konnten für RTQ und Scherkraftberechnungen für die Kontrollimplantate gezeigt werden. Für keinen anderen Parameter konnten statistisch signifikante Unterschiede gefunden werden. Schlussfolgerungen: Die Ergebnisse dieser Studie zeigen, dass der Einsatz von EMD nicht zur Knochenbildung um Titanimplantate beiträgt. Diese Beobachtung kann darauf hinweisen, dass die Knochenbildung, die nach Gabe von EMD in parodontalen Defekten stattfindet, das Ergebnis funktioneller Adaptation ist. Allerdings sind weitere Untersuchungen erforderlich, um die Auswirkung von EMD auf die Knochenbildung zu verstehen. Résumé Dérivés de la matrice amellaire et implants en titane. Une étude pilote expérimentale sur le lapin. But: Le but de cette étude était d'évaluer si un dérivé de la matrice amellaire (Emdogain®) pouvait augmenter la formation osseuse et l'ostéo-intégration d'implants en titane en utilisant un modèle éprouvé de lapin. Matériel et méthodes: 36 implants en titane commercialement purs (cp.ti.) ont été vissés chez 6 lapins blancs de Nouvelle Zélande. 1 implant fut placé dans chaque fémur et 2 dans chaque tibia. Préalablement à l'insertion, environ 0.5 mL d' Emdogain (EMD) (test) ou du gel vecteur (PGA: propylene glycol alginate) (control) fut injecté dans le site implantaire préparé chirurgicalement. Le suivi était réalisé sur 6 semaines. Des évaluations biomécaniques par analyse de la fréquence de résonance (RFA) et des mesures de torque de retrait (RTQ) furent utilisées. Les quantifications histo-morphométriques furent réalisées sur des coupes en mesurant le pourcentage de contact os-métal, les surfaces osseuses à l'intérieur ainsi qu'à l'extérieur des spires (Image miroir). Les longueurs d'os le long des surfaces implantaires furent aussi mesurées et utilisées pour calculer les forces de cisaillement. Résultats: Les résultats n'ont montré aucun effet bénéfique du traitement à l'EMD sur la formation osseuse autour des implants en titane pour aucun des paramètres test. De significatives différences furent trouvées avec le test de torque et les calculs de force de cisaillement pour les implants contrôles. Aucun autre paramètre ne montrait de différences statistiquement significatives. Conclusion: Les résultats de cette étude pourrait indiquer que l'EMD ne contribue pas à la formation osseuse autour des implants en titane. Cette observation peut indiquer que la formation osseuse qui survient après traitement à l'EMD dans les lésions parodontales serait le résultat d'une adaptation fonctionnelle. Cependant, de futures recherches sont nécessaires pour évaluer l'effet du traitement à l'EMD sur la formation osseuse. [source]

Polyethylene cross-linking by two different methods reduces acetabular liner wear in a hip joint wear simulator

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2003
Darryl D. D'Lima
Advances in cross-linking have led to the development of wear resistant ultrahigh molecular weight polyethylene for total joint replacement. This study compared wear reduction by two different cross-linking methods as measured in a hip wear simulator. One highly cross-linked polyethylene was treated with 7.5 Mrad gamma irradiation with post-irradiation annealing and a sterilization dose of 2.5 Mrad (10 Gamma), while the other used 9.5 Mrad warm irradiation with 10 MeV electron-beam (9.5 EB). Liners of the same design, made from nominally cross-linked (gamma sterilized) polyethylene were also tested. Gravimetric wear analysis was performed every 500,000 cycles for 5,000,000 cycles. After correcting for weight gain due to water absorption, the nominally cross-linked liners demonstrated mean wear rates of 15.7 (±1.7) and 12.5 (±1.0) mg/million cycles. Both highly cross-linked polyethylene liners demonstrated significantly less wear than their respective controls (with mean wear rates of 1.5 (±1.2) and ,1.4 (±1.5) mg/million cycles). The 9.5 EB liners gained weight presumably due to increased fluid absorption, in addition to that measured in loaded,soaked control implants. Any wear occurring was therefore assumed to have been more than offset by weight gain. Highly cross-linked polyethylene was significantly more wear resistant than non- or nominally cross-linked polyethylene. The differences in wear rates between the two highly cross-linked polyethylene designs (9.5 EB or 10 Gamma) are probably too small to be clinically significant. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source]

Locally delivered rhTGF-,2 enhances bone ingrowth and bone regeneration at local and remote sites of skeletal injury

Laser-Welded Titanium Frameworks Supported by Implants in the Partially Edentulous Mandible: A 10-Year Comparative Follow-Up Study

CLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 3 2008
Anders Örtorp DDS, PhD/Odont Dr
ABSTRACT Background: Comparative long-term knowledge of different framework materials in the partially edentulous implant patient is not available. Purpose: To report and compare 10-year data on free-standing implant-supported partial prostheses with laser-welded titanium (test) and conventional gold alloy (control) frameworks. Materials and Methods: Altogether, 52 partially edentulous patients were consecutively provided with laser-welded prostheses (n = 60) in the partially edentulous lower jaw (test group). A control group of 52 randomly selected patients with gold alloy castings (n = 60) was used for comparison. Clinical and radiographic 10-year data were retrospectively collected and evaluated for both groups. Results: The overall 10-year implant cumulative survival rate (CSR) was 93.0% (loaded implants, 96.4%), with a 10-year implant CSR of 91.5 and 94.7% for test and control implants, respectively (p > .05). Out of a total of 22 lost implants, 17 implants (77.3%) were shorter than 10 mm. The overall 10-year prosthesis CSR was 93.7%, with a corresponding 10-year CSR of 88.4 and 100% for test and control groups, respectively (p < .05). Average 10-year bone loss was 0.46 mm (SD 0.47) and 0.69 mm (SD 0.53) for the test and control groups (p < .001), respectively. Only 1% of the implants had >3 mm accumulated bone loss after 10 years. Altogether, 10 of the prostheses in both groups had implant component mechanical problems (8.3%). None of the frameworks or implants fractured, but more fractures of porcelain veneers were observed in the test group (p < .05). Conclusion: The protocol of implant treatment in the partially edentulous jaw functioned well during 10 years, although prosthodontic maintenance was required. However, laser-welded titanium frameworks presented more problems as compared with gold alloy frameworks. More loaded implants were lost (p < .05), and higher incidence of porcelain chipping was noted in the test group (p < .05). However, bone loss was on an average lower for the test group during the 10 years of follow-up (p < .001). [source]

One-Year Prospective Three-Center Study Comparing the Outcome of a "Soft Bone Implant" (Prototype Mk IV) and the Standard Brånemark Implant

Transmucosal healing around peri-implant defects: crestal and subcrestal implant placement in dogs

CLINICAL ORAL IMPLANTS RESEARCH, Issue 8 2010
Binh L. T. Tran
Abstract Objective: This study was designed to evaluate the transmucosal healing response of implants placed with the junction of the smooth surfaces, either crestal or subcrestal, into simulated extraction defects after healing periods of 1 and 3 months. Materials and methods: A total of 23 Straumann SP ,3.3 mm NN, SLA® 10 mm implants were placed in the mandibular premolar regions of three greyhound dogs 3 months after the teeth were removed. Five control implants were placed at the crestal bone level, and test implants with surgically created peri-implant defects of 1.25 mm wide × 5 mm depth were placed either at the crestal (nine implants) or at the 2 mm subcrestal (nine implants) bone level. Implants on the right side were placed 1 month before the dogs were sacrificed, and implants on the left side were placed 3 months before sacrifice. All dogs had daily plaque control following surgery and were sacrificed 3 months after implant placement for histological and histometric analyses. Results: Mesial,distal ground sections of the control and test implant specimens showed a greater %BIC in the coronal defect region after 3 months of healing. This healing response was incomplete for the test implants compared with the control implants after a 1-month healing period. The histometric measurements for test implants placed at the crestal bone level or 2 mm subcrestal with surgically created peri-implant defects were more coronal or closer to the implant margin compared with the control implants. Additionally, the degree of osseointegration between the newly formed bone and the implant surface was similar between the test implants. Conclusion: Peri-implant defects of 1.25 mm width healed with spontaneous bone regeneration around implants placed transmucosally at crestal or 2 mm subcrestal with a high degree of osseointegration after a 3-month healing period. To cite this article: Tran BLT, Chen ST, Caiafa A, Davies HMS, Darby IB. Transmucosal healing around peri-implant defects: crestal and subcrestal implant placement in dogs. Clin. Oral Impl. Res. 21, 2010; 794,803. doi: 10.1111/j.1600-0501.2010.01911.x [source]

Accuracy of a computerized tomography-guided template-assisted implant placement system: an in vitro study

CLINICAL ORAL IMPLANTS RESEARCH, Issue 10 2009
Jacob Horwitz
Abstract Objectives: To evaluate the accuracy of computer-assisted 3D planning and implant insertion using computerized tomography (CT). Materials and methods: Nine implants were planned on pre-operative CTs of six resin models, which were acquired with radiographic templates, using a planning software (E implants). Each resin model contained three pre-existing control implants (C implants). Radiographic templates were converted into operative guides containing 4.8-mm-diameter titanium sleeves. A single set of insertable sleeves was used for consecutively drilling the six models, followed by implant insertion through the guide sleeves. Models were further divided into group A (the first three models) and group B (the last three models). Post-operative CTs were used to compare implant positions with pre-operative planned positions. Statistical analysis included the Mann,Whitney U test for E and C implants and the Wilcoxon's signed ranks test for groups A and B. Results: The mean apex depth deviations for E and C implants [0.49 mm±0.36 standard deviation (SD) and 0.32 mm±0.21 SD, respectively], and the mean apex radial deviations (0.63 mm±0.38 SD and 0.49 mm±0.17 SD, respectively) were similar (P>0.05). The mean angulation deviations for E and C implants were 2.17±1.06°SD and 1.33±0.69°SD, P<0.05. E implant deviations of all the parameters in group A were significantly smaller than E implant deviations in group B. Conclusions: Computer-assisted implant planning and insertion provides good accuracy. Deviations are mainly related to system and reproducibility errors. Multiple use of drills and titanium sleeves significantly reduces system accuracy. [source]

A randomized-controlled clinical trial evaluating clinical and radiological outcomes after 3 and 5 years of dental implants placed in bone regenerated by means of GBR techniques with or without the addition of BMP-2

CLINICAL ORAL IMPLANTS RESEARCH, Issue 7 2009
Ronald E. Jung
Abstract Objective: The aim of this randomized-controlled clinical trial was to evaluate the long-term outcome of implants placed in bone augmented with a xenogenic bone substitute material and a collagen membrane with or without the addition of recombinant human bone morphogenetic protein-2 (rhBMP-2). Material and methods: Eleven patients received a total of 34 implants placed into sites exhibiting lateral bone defects. In a split mouth design, the defects were randomly treated with the graft material and the collagen membrane either with (test) or without (control) rhBMP-2. The patients were examined 3 and 5 years after insertion of the prosthetic restoration. Student's paired t -test was performed to detect differences between the two groups. Results: The survival rate at 3 and 5 years was 100% for both groups. The peri-implant soft tissues were stable and healthy without any difference between the two groups. The prosthetic reevaluation demonstrated four loose prosthetic screws during the first 3 years and seven ceramic chippings after 3 and 5 years. The mean distance between the first bone to implant contact to implant abutment junction at 3 years was 1.37 mm (test), 1.22 mm (control), and 1.38 mm (test), and 1.23 mm (control) at 5 years. The difference of <0.2 mm between test and control implants was not statistically significant. The mean change of the marginal bone level between baseline and 5 years ranged from ,0.07 mm (mesial, test), ,0.11 mm (distal, test), ,0.03 mm (mesial, control), to +0.13 mm (distal, control). No statistically significant differences were observed between test and control sites. Conclusion: Implants placed in bone augmented with and without rhBMP-2 revealed excellent clinical and radiological outcomes after 3 and 5 years. [source]

Subcrestal placement of two-part implants

CLINICAL ORAL IMPLANTS RESEARCH, Issue 3 2009
Maria Welander
Abstract Objective: The aim of the present experiment was to study the healing around two-part implants that were placed in a subcrestal position. Material and methods: Five mongrel dogs, about 2 years old, were included. The mandibular premolars and the first, second and third maxillary premolars were extracted. Three months later two test and two control implants (OsseoSpeedÔ, 3.5 mm × 8 mm) were placed in one side of the mandible. The implants were placed in such a way that the implant margin was located 2 mm apical to the bone crest. In the test implants, the surface modification extended to the implant margin and, thus, included the shoulder part of the implant. Regular abutments with a turned surface (ZebraÔ) were connected to the control implants, while experimental abutments with a modified surface (TiOblastÔ) were connected to the test implants. A plaque control program that included cleaning of implants and teeth every second day was initiated. Four months later the dogs were euthanized and biopsies were obtained and prepared for histological analysis. Results: The marginal bone level at the test implants was identified in a more coronal position than that at the control implants. In 40% of the test implants, the bone-to-implant contact extended coronal of the abutment/fixture (A/F) border, i.e. in contact with the abutment part of the implant. The connective tissue portion of the peri-implant mucosa that was facing the test abutments contained a higher density of collagen and a smaller proportion of fibroblasts than that at the control sites. Conclusion: It is suggested that osseointegration may occur coronal to the A/F interface of two-part implants. Such a result, however, appears to depend on the surface characteristics of the implant components. [source]

Orthodontic load on short maxillary implants with reduced sink depth: an experimental study

CLINICAL ORAL IMPLANTS RESEARCH, Issue 10 2008
H. Wehrbein
Abstract Objective: The aim of this study was to investigate experimentally the positional stability and histomorphometric findings of length-reduced temporary anchorage devices (Orthosystem®, length: 4 mm) with reduced sink depth. Material and methods: For this purpose, four maxillary pre-molars (2P2, 3P3) were extracted from each of four foxhounds. After a 16-week alveolar healing period, 16 implants (four per dog) were inserted into the edentulous areas. Four implants (one per dog) were placed simultaneously in the mid-palatal area. The implants were intentionally submerged to about three-quarters of their length. After a 10-week unloaded implant healing period, the implants in the P3 areas and the palate were loaded (test implants) by means of transpalatal bars fixed on the implants in the P3 areas and Sentalloy traction springs (,2 N continuous force) inserted mid-sagittally between palatal implants and bars (force application period: 24 weeks). The implants in the P2 areas served as controls. Results: Clinical measurements and histological evaluation revealed positional stability of the loaded fixtures. Alveolar control implants (ACI) were inserted to a mean depth of 3.2 mm, alveolar test implants (ATI) to 3.3 mm and palatal test implants (PTI) to 2.6 mm. The mean direct bone contact percentage values were 71.3% (ACI), 79.6% (ATI) and 72.2% (PTI). Conclusion: These results suggest that, probably due to the relatively high percentage of bone contact with implant surface, only 3 mm of intrabony implant length is sufficient to retain positional stability during long-term orthodontic loading. [source]

Positive effect of early loading on implant stability in the bi-cortical guinea-pig model

CLINICAL ORAL IMPLANTS RESEARCH, Issue 4 2005
Els De Smet
Abstract: Loading, early after implant placement, has gained rapid interest in dentistry. Primary implant stability, as e.g. defined by resonance frequency instrumentation, has been isolated as a predicator when immediate and early implant loading is applied. The aim of this study was to investigate the effect of early (after 7 days) mechanical loading on the establishment of osseointegration by means of resonance frequency analysis (RFA). Percutaneous titanium implants were installed in both tibiae of 10 guinea-pigs. One week after implant installation, one implant (test) was loaded daily for 6 weeks, while the contra-lateral served as the unloaded one (control). A sinusoidally varying bending moment was applied at a frequency of 3 Hz and a force amplitude of 5 N, for 1800 cycli. Resonance frequency was measured at implant installation and from then on weekly using the RFA-device (Osstell®). Contrary to control implants, that showed a decrease in stability 1 week after installation, reaching a minimum at 3 weeks (,200 Hz), test implants showed a progressive increase in stability over time. After 6 weeks, the mean resonance frequency of test and control implants reached the same values. As confirmed by recent literature, early loading does not have to endanger the establishment of osseointegration of titanium implants. On the contrary, controlled loading is beneficial to maintain the implant stability during the early critical healing period as determined by RFA-measurements. Résumé La mise en charge précoce après l'insertion de l'implant acquière beaucoup d'intérêt en médecine dentaire. La stabilité primaire de l'implant, qui est par exemple définie par l'instrumentation de fréquence de résonnance RFA, a été isolée comme un annonciateur lorsque la mise en charge de l'implant était précoce ou immédiate. Le but de cette étude a été d'étudier l'effet d'une mise en charge précoce (sept jours) sur l'établissement de l'ostéïntégration à l'aide de RFA (Osstell®). Des implants titane percutanés ont été insérés dans les deux tibias de dix cobayes. Une semaine après le placement des implants, un implant test a été mis en charge tous les jours pendant six semaines tandis que le contralatéral servait de contrôle et n'était pas mis en charge. Un moment sinusoïdal a été appliquéà une fréquence de trois hertz et une amplitute d'une force de 5 N pour 1 800 cycles. La fréquence de résonnance a été mesurée lors de l'insertion de l'implant et ensuite hebdomadairement en utilisant le RFA. Contrairement aux implants contrôles, qui accusaient une diminution de la stabilité une semaine après leur insertion atteignant un minimum après trois semaines (,200 Hz), les implants tests ont montré une augmentation progressive de la stabilité avec le temps. Après six semaines, la fréquence de résonnance moyenne des implants tests et contrôles atteignaient les mêmes valeurs. Comme décrit dans la littérature récente, la mise en charge précoce ne met pas en danger l'établissement de l'ostéoïntégration des implants en titane. Au contraire, une mise en charge contrôlée est bénéfique au maintien de la stabilité implantaire durant la période de guérison critique précoce comme déterminée par les mesures RFA. Zusammenfassung Die Belastung kurz nach der Implantatplatzierung hat in der Zahnmedizin schnell an Interesse gewonnen. Die Primärstabilität der Implantate, bestimmt z.B. durch Messung der Resonanzfrequenz, hat sich als Voraussagewert herauskristallisiert, wenn eine Sofort-oder Frühbelastung der Implantate durchgeführt wird. Das Ziel dieser Studie war, den Einfluss der frühen (nach 7 Tagen) mechanischen Belastung auf die Ausbildung der Osseointegration mittels Resonanzfrequenzanalyse (RFA) zu untersuchen. In die beiden Tibias von 10 Meerschweinchen wurden perkutane Titanimplantate eingesetzt. Eine Woche nach der Implantation wurde ein Implantat (Test) während 6 Wochen täglich belastet, während das kontralaterale Implantat unbelastet blieb (Kontrolle). Es wurde ein Biegemoment mit sinusoidalen Schwankungen mit einer Frequenz von 3 Hz und einer Kraftamplitude von 5 N in 1800 Zyklen appliziert. Die Resonanzfrequenz wurde nach der Implantation und dann wöchentlich mit einem RFA-Gerät (Osstell®) gemessen. Im Gegensatz zu den Kontrollimplantaten, welche eine Woche nach dem Setzen eine Stabilitätsabnahme zeigten und das Minimum nach drei Wochen (,200 Hz) erreichten, konnte bei den Testimplantaten eine progressive Zunahme der Stabilität über die Zeit beobachtet werden. Nach sechs Wochen erreichten die mittleren Resonanzfrequenzen der Test-und Kontrollimplantate dieselben Werte. Die frühe Belastung gefährdet die Ausbildung einer Osseointegration bei Titanimplantaten nicht, was auch durch die neuere Literatur bestätig wird. Im Gegenteil, eine kontrollierte Belastung ist von Vorteil für den Erhalt der Implantatstabilität während der kritischen frühen Einheilphase. Dies konnte mittels RFA Messungen ermittelt werden. Resumen La carga temprana tras la colocación del implante ha ganado rápidamente interesen odontología. Se ha aislado como predictor, la estabilidad primaria del implante, definida por instrumentación de frecuencia de resonancia, cuando se aplica la carga temprana al implante. La intención del estudio fue investigar el efecto de carga mecánica temprana (tras 7 días) en el establecimiento de la osteointegración por medio del análisis de la frecuencia de resonancia (RFA). Se instalaron implantes de titanio percutaneos en ambas tibias de 10 conejos de indias. Una semana tras la instalación, un implante (prueba) se cargó diariamente durante 6 semanas, mientras que el contralateral sirvió como el implante sin carga (control). Se aplicó un momento de flexión variante sinusoidalmente a una frecuencia de 3 Hz y una amplitud de la fuerza de 5 N, durante 1899 ciclos. Se midió la frecuencia de resonancia al instalar el implante y a partir de ahí semanalmente usando el dispositivo RFA (Ostell®). Contrariamente a los implantes de control, que mostraron una disminución de la estabilidad una semana después de la instalación, alcanzando un mínimo a las tres semanas (,200 Hz), los implantes de prueba mostraron un incremento progresivo de la estabilidad a lo largo del tiempo. Tras seis semanas, la frecuencia de resonancia de los implantes de prueba y de control alcanzaron los mismos valores. Tal como se confirma por la literatura reciente, la carga temprana no debe hacer peligrar el establecimiento de la osteointegración de los implantes de titanio. Por lo contrario, la carga controlada es beneficiosa para mantener la estabilidad de los implantes durante el periodo crítico de la cicatrización determinado por las mediciones de RFA. [source]

Influence of implant taper on the primary and secondary stability of osseointegrated titanium implants

CLINICAL ORAL IMPLANTS RESEARCH, Issue 4 2004
Dominic O'Sullivan
Abstract Objectives: The study presented was designed to analyse the mechanical performance and the primary and secondary stability characteristics of endosseous titanium implants with 1° (EXP1) and 2° (EXP2) of taper when compared with the standard Brånemark design (Nobel Biocare AB, Gothenburg, Sweden). Materials and methods: One pair of 10 mm EXP1 and control implants were placed in the femoral condyles of six rabbits. Paired 6 mm EXP1 and control implants and 6 mm EXP2 and control implants were placed in the tibial metaphysis. The control implants used were 4 mm diameter standard Brånemark implants, the same length as the test implants. At placement, insertion torque (IT) and resonance frequency analysis (RFA) measurements were performed. Six weeks postoperatively when the animals were killed, RFA and removal torque (RT) measurements were made. Results: At placement, significantly higher IT was needed to insert the EXP implants compared with the controls. RFA values were significantly higher for EXP1 implants placed in the tibia but not in the femur. In pooling data from the femur and tibia there was a significant difference. The EXP2 implants failed to insert fully and demonstrated a lower RFA value than may have been expected due to the exposed threads, although this difference was not statistically significant. Conclusions: The results from the present study showed that 1° of taper results in a better primary stability compared with the standard Brånemark design. There was no evidence that the tapered design caused negative bone tissue reactions. All the implants gained in stability during the healing period. Résumé L'étude présente a été effectuée pour analyser la performance mécanique et les caractéristiques de stabilité primaire et secondaire d'implants endoosseux en titane avec un taper (fuselé) 1° (EXP1) et 2 (EXP 2) comparés au modèle ad modum Branemark® standard. Une paire d'implants contrôles et un EXP1 de 10 mm ont été placés dans les condyles fémoraux de six lapins. Des paires d'implants contrôles et EXP1 de 6 mm et des implants contrôles et EXP2 de 6 mm ont été placés dans les métaphyses tibiales. Les implants contrôles utilisés avaient un diamètre standard de 4 mm, la même longueur que les implants tests. Lors du placement, des mesures de force d'insertion (IT) et d'analyse de fréquence de résonnance (RFA) ont été effectuées. Six semaines après l'opération lorsque les animaux ont été euthanasiés, les mesures RFA et les forces d'enlèvement (RT) ont été relevées. Lors du placement un IT significativement plus important a été nécessaire pour insérer les implants EXP1 comparé au contrôle. Les valeurs RFA étaient significativement plus importantes pour les implants EXP1 placés dans le tibia mais pas dans le fémur. En rassemblant les données du fémur et du tibia il y avait une différence significative. Les implants EXP2 ne parvenaient pas àêtre insérés à fond et ont montré une valeur RFA inférieure qui n'était pas inattendue vu les filetages exposés bien que ces différences n'étaient pas statistiquement significatives. Les résultats de l'étude présente ont montré que le taper 1 résultait en une stabilité primaire supérieure comparé au modèle ad modum Branemark® standard. Il n'y avait aucun signe que ce nouveau modèle causait des réactions tissulaires osseuses négatives. Tous les implants ont gagné en stabilité durant leur période de guérison. Zusammenfassung Ziele: Die hier vorgestellte Studie hatte zum Ziel, das mechanische Verhalten und die Charakteristika von Primär- und Sekundärstabilität bei enossalen Implantaten mit einer Gewindeneigung von 1° (EXP1) und von 2° (EXP2) zu untersuchen. Man verglich die Daten mit dem Standarddesign von Brånemark (Nobel Biocare AB, Gothenburg, Schweden). Material und Methode: Man implantierte ein Päärchen von 10mm-Implantaten (EXP1 und Kontrollimplantat) in die Femurkondylen von 6 Kaninchen. Zwei weitere Päärchen von 6mm-Implantaten (EXP1 und Kontrollimplantat, sowie EXP2 und Kontrollimplantat) implantierte man in die Metaphyse der Tibia. Bei den Kontrollimplantaten handelte es sich um Standardtypen von Brånemark mit einem Durchmesser von 4 Millimetern und derselben Länge wie die Testimplantate. Bei der Implantation mass man die Kraft, die es zu Eindrehen der Implantate brauchte (IT) und führte Messungen mit der Resonanzfrequenzanalyse (RFA) durch. Sechs Wochen nach der Operation wurden die Tiere geopfert, die RFA erneut durchgeführt und anschliessend der Ausdrehwiderstand (RT) bestimmt. Resultate: Bei der Implantation brauchte es signifikant grössere IT um die EXP-Implantate einzusetzen, als bei den Kontrollimplantaten. Die RFA-Werte waren bei den EXP1-Implantaten, die in die Tibia geschraubt worden waren, signifikant höher. Dies gilt aber nicht für die in den Femur geschraubten Implantate. Wurden die Daten vom Femur mit denen der Tibia verglichen, so erkannte man signifikante Unterschiede. Die EXP2-Implantate konnten nicht vollständig inseriert werden und zeigten auch tiefere RFA-Werte, als man den freiliegenden Schraubenwindungen entsprechend erwarten könnte. Diese Unterschiede waren aber nicht statistisch signifikant. Zusammenfassung: Die Resultate dieser Studie zeigten, das Schraubenwindungen mit 1° Steigung verglichen mit dem Standarddesign von Brånemark eine bessere Primärstabilität erzielten. Man fand andererseits keine Beweise, dass sich dieses neue Design der Schraubenwindungen negativ auf die Reaktion des Knochengewebes auswirkt. Alle Implantate gewannen während in der Heilphase an Stabilität dazu. Resumen Objetivos: El estudio presentado se diseñó para analizar el rendimiento mecánico y las características de estabilidad primaria y secundaria de implantes endoóseos de titanio con 1o (EXP1) y 2o (EXP 2) de autoroscado al compararlos con el diseño estándar de Brånemark (Nobel Biocare AB, Gothenburg, Suecia). Material y Métodos: Se colocó una pareja de implantes de 10 mm EXP1 y de control en los cóndilos femorales de 6 conejos. Se colocaron pareja de implantes de 6 mm EXP1 y de control y de 6 mm EXP2 y de control en la metáfisis tibial. Los implantes de control utilizados fueron Brånemark estándar de 4 mm de diámetro. A la colocación, se llevaron a cabo mediciones del torque de inserción (IT) y del análisis de la frecuencia de resonancia (RFA). Los animales se sacrificaron a las seis semanas de la operación, y se tomaron medidas del torque de remoción (RT). Resultados: Al colocarse, se necesitó un IT significativamente mas alto para insertar los implantes EXP en comparación con los de control. Los valores RFA fueron significativamente mas altos para implantes EXP1 colocados en la tibia pero no en el fémur. Confrontando los datos del fémur y de la tibia apareció una diferencia significativa. Los implantes EXP2 fracasaron en insertarse completamente y demostraron un menor valor de RFA del que se podía esperar debido a la exposición de las roscas, aunque esta diferencia no fue estadísticamente significativa. Conclusiones: Los resultados del presente estudio mostraron que 1o de autoroscado resultan en una mejor estabilidad primaria comparada con el diseño estándar de Brånemark. No hubo evidencia de que el diseño de autoroscado causara reacciones negativas en el tejido óseo. Todos los implantes ganaron estabilidad durante el periodo de cicatrización. [source]

Early loading (2 or 6 weeks) of sandblasted and acid-etched (SLA) ITI® implants in the posterior mandible

CLINICAL ORAL IMPLANTS RESEARCH, Issue 2 2004
A 1-year randomized controlled clinical trial
Abstract: The aim of this 1-year prospective controlled clinical trial was to evaluate the effect of early loading of ITI® solid screw titanium implants with a sandblasted and acid-etched (SLA) surface on clinical and radiographic parameters. Material and methods: Twenty-seven consecutively admitted patients presenting bilateral edentulous posterior mandibular areas and in need of prosthetic reconstruction were recruited. Sixty-seven ITI® standard solid screw implants with an SLA surface, a diameter of 4.1 mm and a length of 8, 10 or 12 mm were installed bilaterally in molar and premolar areas according to a one-stage surgical protocol. One week (test) and 5 weeks (control) after implant placement, solid ITI® prosthetic abutments were connected using a torque of 35 N cm. No provisional restoration was fabricated. Two weeks (test) and 6 weeks (control) after implant placement, porcelain-fused-to-metal single-tooth crowns were cemented. Clinical measurements were obtained at day 0 and 2, 6, 12, 24 and 52 weeks thereafter. Periapical radiographs were taken immediately after implant placement, after 6 weeks and at the 1-year examination. Results: After 1 year, implant survival was 100%. Two test and one control implants rotated at the time of abutment connection and were left unloaded for 12 additional weeks. At the 1-year examination, no statistically significant differences were found between the test and control sites with respect to pocket probing depths (2.6 mm±0.5 vs. 2.7 mm±0.5), mean clinical attachment levels (3.1 mm±0.4 vs. 3.2 mm±0.5), mean percentages of sites bleeding on probing (9.7% vs. 8.3%), mean widths of keratinized mucosa (1.8 mm±0.4 vs. 1.9 mm±0.5), mean PerioTest® values (,1.4 PTV±0.9 vs. ,1.6 PTV±0.8) or mean crestal bone loss measurements (0.57 mm±0.49 vs. 0.72 mm±0.50). Conclusion: Based on these results, loading of titanium implants with an SLA surface as early as 2 weeks did not appear to jeopardize the osseointegration healing process in the posterior mandible. Furthermore, implants rotating at 35 N cm, if left unloaded for additional 12 weeks, did not negatively affect clinical and radiographic outcomes. Résumé Le but de cet essai clinique contrôlé prospectif d'une année a été d'évaluer l'effet de la mise en charge précoce d'implants en titane vis solide ITI® avec une surface sablée et mordancée (SLA) sur des paramètres cliniques et radiographiques. Vingt-sept patients présentant des aires bilatérales mandibulaires postérieures édentées et nécessitant donc une reconstruction prothétique ont été recrutés. Soixante-sept implants ITI® d'un diamètre de 4,1 mm et d'une longueur de 8, 10 ou 12 mm ont été placés bilatéralement dans les zones molaires et prémolaires suivant le processus chirurgical en une étape. Une semaine (test) et cinq semaines (contrôle) après leur placement des piliers prothétiques ITI® ont été serrés avec une force de 35 Ncm. Aucune restauration provisoire n'a été fabriquée. Deux semaines (test) et six semaines (contrôle) après le placement des implants des couronnes céramo-métalliques indépendantes ont été cimentées. Des mesures cliniques ont été obtenues aux jours 0 et deux, et aux semaines 6, 12, 24 et 52. Des radiographies périapicales ont été prises immédiatement après le placement des implants, après six semaines et une année. Après une année, le taux de survie implantaire était de 100%. Deux implants tests et un contrôle pivotaient au moment de la connexion du pilier et ont été laissés non-chargés pour 12 semaines supplémentaires. Après une année, aucune différence statistique n'a été trouvée entre les sites tests et contrôles en ce qui concerne les profondeurs de poches au sondage (2,6 ±0,5 mm vs 2,7± 0,5 mm), les niveaux d'attache clinique moyens (3,1±0,4 vs 3,2±0,5 mm,) les pourcentages moyens de sites saignant au sondage (9,7% vs 8,3%), les largeurs moyennes de muqueuse attachée (1,8±0,4 mm vs 1,9±0,5 mm), les valeurs Periotest moyennes (,1,4±0,9 PTV vs ,1,6 ±0,8 PTV) ou les mesures de perte osseuse crestale moyennes (0,57 ± 0,49 mm vs 0,72±0,52 mm). La charge d'implants en titane avec surface SLA aussitôt que deux semaines après leur placement ne semblait pas mettre en danger le processus d'ostéoïntégration dans la partie postérieure de la mandibule. De plus, les implants pivotant à 35 Ncm, si laissés non-chargés pour douze semaines supplémentaires, n'affectaient pas de manière négative les mesures cliniques et radiographiques. Zusammenfassung Material und Methoden: Es wurden siebenundzwanzig Patienten mit beidseits zahnlosem Seitenzahnbereich im Unterkiefer, welche eine prothetische Versorgung benötigten, in die Studie aufgenommen. Es wurden 67 ITI® Standard Vollschraubenimplantate mit einem Durchmesser von 4.1 mm und einer Länge von 8, 10 oder 12 mm beidseits in der Molaren- und Prämolarenregion transmukosal eingesetzt. Eine Woche (Test) und 5 Wochen (Kontrolle) nach Implantation wurden ITI® Massivsekundärteile mit einem Drehmoment von 35 Ncm eingesetzt. Es wurde keine provisorische Versorgung angefertigt. Zwei Wochen (Test) und 6 Wochen (Kontrolle) nach Implantation wurden Gold-Porzellan Einzelkronen einzementiert. Klinische Messungen wurden am Tag 0 und nach 2, 6, 12, 24, und 52 Wochen aufgenommen. Periapikale Röntgenaufnahmen wurden sofort nach der Implantation, nach 6 Wochen und anlässlich der 1 Jahreskontrolle angefertigt. Resultate: Nach einem Jahr betrug die Implanta-tüberlebensrate 100%. Zwei Test- und ein Kontrollimplantat drehten sich beim Einschrauben der Sekundärteile und wurden für zusätzliche 12 Wochen unbelastet belassen. Bei der 1 Jahresuntersuchung konnten zwischen Test- und Kontrolli-mplantaten keine statistisch signifikanten Unterschiede bezüglich Sondierungswerten (2.6mm+/,0.5 gegenüber 2.7mm +/,0.5), mittlerem klinischem Attachmentniveau (3.1mm +/,0.4 gegenüber 3.2mm +/,0.5), mittlerem Prozentanteil beim Bluten auf Sondieren (9.7% gegenüber 8.3%), mittlerer Breite der keratinisierten Mukosa (1.8mm +/,0.4 gegenüber 1.9mm +/,0.5), mittleren Periotest® Werten (,1.4 PTV +/,0.9 gegenüber ,1.6 PTV +/,0.8) oder mittlerem marginalem Knochenverlust (0.57mm +/,0.49 gegenüber 0.72mm +/,0.50) gefunden werden. Schlussfolgerung: Gemäss dieser Resultate schien die Belastung von Titanimplantaten mit SLA Oberfäche bereits nach 2 Wochen den Heilungsprozess der Osseointegration im posterioren Unterkiefer nicht zu beeinträchtigen. Implantate, die bei 35Ncm rotierten und daraufhin für weitere 12 Wochen unbelastet blieben, beeinflussten die klinischen und radiologischen Resultate nicht negativ. Resumen La intención de este ensayo clínico prospectivo controlado fue evaluar el efecto de una carga temprana sobre implantes macizos roscados de titanio con una superficie pulverizada con arena y gravada con ácido (SLA) sobre parámetros clínicos y radiográficos. Material y Métodos: Se reclutaron veintisiete pacientes consecutivamente admitidos que presentaron áreas edéntulas bilaterales en la mandíbula posterior y necesitando reconstrucción protésica. Se instalaron bilateralmente en las áreas molar y premolar sesenta y siete implantes ITI® estándar macizos roscados de titanio con una superficie SLA, un diámetro de 4.1 mm y una longitud de 8, 10 o 12 mm de acuerdo con un protocolo quirúrgico de una sola fase. Una semana (prueba) y 5 semanas (control) tras la colocación del implante, se conectaron pilares prostéticos macizos ITI usando un torque de 35 Ncm. No se fabricaron restauraciones provisionales. Dos semanas (prueba) y 6 semanas (control) tras la colocación de los implantes, se cementaron coronas unitarias metalocerámicas. Se obtuvieron medidas clínicas en el día 0 y tras 2, 6, 12, 24 y 52 semanas. Se tomaron radiografías periapicales inmediatamente tras la colocación del implante, a las 6 semanas y en el examen de 1 año. Resultados: Tras 1 año, la supervivencia de los implantes fue del 100%. Dos implantes de prueba y uno de control rotaron en el momento de la conexión del pilar y se dejaron sin carga durante 12 semanas más. En el examen de 1 año, no se encontraron diferencias significativas entre los lugares de prueba y los de control respecto a las profundidades de sondaje (2.6 mm±0.5 vs. 2.7 mm±0.5), niveles medios de inserción clínica (3.1±mm±0.4 vs. 3.2 mm±0.5), porcentaje medio de lugares con sangrado al sondaje (9.7% vs. 8.3%), anchura media de mucosa queratinizada (1.8 mm±0.4 vs. 1.9 mm±0.5), valores medios de Perio Test® (,1.4 PTV±0.9 vs. ,1.6 PTV±0.8) o a las medidas medias de perdida de hueso crestal (0.57 mm±0.49 vs. 0.72 mm±0.50). Conclusiones: Basándose en estos resultados, la carga de implantes de titanio con superficie SLA tan pronto como a las 2 semanas no pareció comprometer el proceso de cicatrización de la osteointegración en la mandíbula posterior. Mas aun, los implantes que rotaron a 35 Ncm, si se dejan sin carga durante 12 semanas más, no afectaron negativamente los resultados clínicos y radiográficos. [source]

Microbiological findings and host response in patients with peri-implantitis

CLINICAL ORAL IMPLANTS RESEARCH, Issue 4 2002
Margareta Hultin
Abstract: The aim of the present study was to characterise microbiota and inflammatory host response around implants and teeth in patients with peri-implantitis. We included 17 partly edentulous patients with a total of 98 implants, of which 45 showed marginal bone loss of more than three fixture threads after the first year of loading. Nineteen subjects with stable marginal tissue conditions served as controls. Oral hygiene, gingival inflammation, and probing pocket depth were evaluated clinically at teeth and implants. Microbiological and crevicular fluid samples were collected from five categories of sites: 1) implants with peri-implantitis (PI), 2) stable implants (SI) in patients with both stable and peri-implantitis implants, 3) control implants (CI) in patients with stable implants alone, 4) teeth in patients (TP) and 5) controls (TC). Crevicular fluid from teeth and implants was analysed for elastase activity, lactoferrin and IL-1, concentrations. Elastase activity was higher at PI than at CI in controls. Lactoferrin concentration was higher at PI than at SI in patients with peri-implantitis. Higher levels of both lactoferrin and elastase activity were found at PI than at teeth in patients. The concentrations of IL-1, were about the same in the various sites. Microbiological DNA-probe analysis revealed a putative periodontal microflora at teeth and implants in patients and controls. Patients with peri-implantitis harboured high levels of periodontal pathogens, Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Bacteroides forsythus and Treponema denticola. These findings indicate a site-specific inflammation rather than a patient-associated specific host response. [source]