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Teeth
Kinds of Teeth Terms modified by Teeth Selected AbstractsFERRULES FOR ENDODONTICALLY TREATED TEETHJOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 5 2009Yoshihiro Goto DDS [source] BONDING TO FLUOROSED TEETHJOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 4 2009PhD Guest Experts, R. Banu Ermis DDS [source] INFLUENCE OF MEASUREMENT TECHNIQUE, TEST FOOD, TEETH AND MUSCLE FORCE INTERACTIONS IN MASTICATORY PERFORMANCEJOURNAL OF TEXTURE STUDIES, Issue 1 2007FLÁVIA RIQUETO GAMBARELI ABSTRACT The role of texture and flavors in mastication is evident, but it is difficult to understand the interactions among food properties, oral physiology and perception. Mastication results from rhythmic mandibular movements. The teeth and masticatory muscles together form the mechanism whereby the food particles are fragmented. Masticatory performance and efficiency are defined as the capacity to reduce natural or artificial test materials during mastication, or by counting the number of strokes required to reduce food, respectively. Foods eaten for nourishment are very different from the industrial test materials used to quantify masticatory performance, thus, divergences could arise if the chewable material can or cannot be swallowed. This study presents a synopsis of masticatory performance methods, which is also related to muscle force, number of teeth and test chewing substance diversity. PRACTICAL APPLICATIONS The attributes of food, such as appearance, flavor and texture, as well as its interaction with saliva, number of teeth and conditions of the biomechanical system, influence the chewing process. In addition, reflex control and cognition can influence food perception and breakdown in the mouth. Food acceptability and choice depend on sensory properties of the food, which are perceived during chewing and swallowing. Masticatory performance and maximal occlusal force measurement may provide essential information that could lead to an appropriate diagnosis as regards masticatory function. Masticatory efficiency and performance can be measured to determine the individual's capacity to comminute a natural or a chewable test material. A material with uniform properties that can be reliably reproduced is essential to provide an ideal test bolus for the scientific study of masticatory effectiveness. [source] PATTERNS OF IRON AGE HORSE SUPPLY: AN ANALYSIS OF STRONTIUM ISOTOPE RATIOS IN TEETH,ARCHAEOMETRY, Issue 1 2009R. BENDREY This paper presents a pilot study of strontium (Sr) isotope ratios from Iron Age horse tooth enamel samples. It compares 87Sr/86Sr ratios from horse teeth to estimates for local ranges of biologically available strontium, to investigate whether horses were being bred at the sites where their remains were discovered. A horse from Middle Iron Age Rooksdown, Hampshire, was not bred at the site but, rather, came from as far away as Wales, Scotland or continental Europe. Horse teeth from Middle Iron Age Bury Hill, Hampshire, returned 87Sr/86Sr values typical of local chalkland. [source] STRESS REDUCTION IN A GEAR TOOTH USING PHOTOELASTICITY AND FINITE ELEMENT ANALYSISEXPERIMENTAL TECHNIQUES, Issue 5 2001A. Ahlqvist No abstract is available for this article. [source] Evaluation of tooth-fragment reattachment: a clinical and laboratory studyDENTAL TRAUMATOLOGY, Issue 4 2010Yucel Yilmaz Materials and Methods:, The clinical study was conducted on 43 fractured incisors: 22 uncomplicated crown fractures (Group A) and 21 complicated crown fractures (Group B). The 43 incisal fragments: 23 were kept dry for 47 h and 20 were kept wet for 24 h by the patients before they were reattached. The fragments were kept in 0.9% saline solution for 30 min before reattachment. The fragments in Group A were reattached using a dentin bonding agent, a flowable and a hybrid resin composite, whereas the fragments in Group B were reattached to the tooth remnant after a pulpotomy was performed. The laboratory study was conducted on 56 extracted incisors. Teeth were divided equally into four groups: Group I , Uncomplicated crown fracture + wet medium; Group II , Uncomplicated crown fracture + dry medium; Group III , Complicated crown fracture + wet medium, and Group IV , Complicated crown fracture + dry medium. The fragments were then reattached in a manner that was similar to that used in the clinical study. The restored teeth were then re-fractured. All data were analyzed statistically. Results: In the clinical study, the restored teeth were followed up for 2 years. Neither the type of trauma nor the storage medium had any significant effect on the survival, color, and bond strength of the restored teeth when assessed in the clinical and laboratory study. The color disharmony that was encountered initially in restored teeth resolved significantly on its own accord within 12 months after reattachment of the fragment. Conclusion: Fragment reattachment can be used to treat fractured teeth successfully in children and adolescents. [source] Evaluation of radiographs, clinical signs and symptoms associated with pulp canal obliteration: an aid to treatment decisionDENTAL TRAUMATOLOGY, Issue 6 2009Adeleke O. Oginni The dental clinician faced with this condition has to make a difficult decision. The aim of this study was to evaluate the clinical signs and symptoms associated with teeth with PCO and to assess the status of the periapical tissues using the periapical index (PAI) as an aid in making a treatment decision. The study included teeth diagnosed with PCO in patients with a history of traumatic injury to the involved teeth. Histories of associated signs and symptoms including pain, swelling and drainage from a sinus tract were elicited. Tooth color, sensibility to electric pulp testing, mobility and percussion tenderness were recorded. The periapical status was assessed using the PAI. Two hundred and seventy-six teeth were diagnosed with PCO. One hundred and fifty-seven (56.9%) and 119 (43.1%) demonstrated partial or total PCO, respectively. Yellow discoloration presented most frequently, occurring in 186 (67.4%) teeth. Sixty-two (33.3%) of these had developed periapical lesions and reacted negatively to sensibility testing. Fifty-seven (30.7%) of these teeth presented radiographically with a normal periapical appearance and reacted normally to sensibility testing, whereas 67 (36.0%) presented with small changes in the periapical bone pattern and reacted in the high normal range to sensibility testing. Teeth with PAI scores ,2 presented with occasional spontaneous pain. Teeth with PAI scores ,3 presented with clinical symptoms and signs ranging from pain on percussion to spontaneous pain, and slight swelling to sinus tract drainage. Based on the findings of this study, endodontic treatment should be initiated in teeth with tenderness to percussion, PAI scores ,3 and a negative response to sensibility testing. [source] Evaluation of fracture resistance in simulated immature teeth using resilon and ribbond as root reinforcements , An in vitro studyDENTAL TRAUMATOLOGY, Issue 4 2009Hiremath Hemalatha Material and Methods:, Sixty five freshly extracted human maxillary anterior teeth were prepared with a Peeso no. 6 to simulate immature teeth (Cvek's stage 3 root development). After instrumentation, each root was irrigated with sodium hypochlorite and with ethylene diamino tetra acetic acid to remove the smear layer. To simulate single visit apexification technique a 4,5 mm white Pro Root mineral trioxide aggregate plug was placed apically using schilder carrier. The teeth were divided into three experimental groups and one control group. Group I , control group (root canals instrumented but not filled); Group II , backfilled with thermoplastisized gutta-percha using AH plus sealer; Group III , reinforced with Resilon using epiphany sealer; Group IV , reinforced with Ribbond fibers using Panavia F luting cement. A Universal Testing Machine was used to apply a load, at the level of the lingual cementoenamel junction with a chisel-shaped tip The peak load to fracture was recorded and statistical analysis was completed using student's t -test. Results:, Values of peak load to fracture were 1320.8, 1604.88, 1620, and 1851newtons for Group I to Group IV respectively. The results of student's t -test, revealed no significant difference (P > 0.05,) between Group II and Group III. Comparison between Group IV and Group III and between Group IV and Group II revealed highly significant difference (P > 0.001). Conclusions:, Teeth reinforced with Ribbond fibers using Panavia F luting cement showed the highest resistance to fracture. Resilon could not strengthen the roots and showed no statistically significant difference when compared with thermopasticised gutta-percha in reinforcing immature tooth when tested with universal testing machine in an experimental model of immature tooth. [source] Effect of root surface treatment with propolis and fluoride in delayed tooth replantation in ratsDENTAL TRAUMATOLOGY, Issue 6 2008Jéssica Lemos Gulinelli Nevertheless, an extended extraoral period damages the periodontal ligament and results in external root resorption. The purpose of this study was to assess by histologic and histometric analysis, the influence of propolis 15% (natural resinous substance collected by Apis mellifera bees from various plants) and the fluoride solution used as root surface treatment on the healing process after delayed tooth replantation. Thirty Wistar (Rattus norvegicus albinus) rats were submitted to extraction of their upper right incisor. The teeth were maintained in a dry environment for 60 min. After this, the pulp was extirpated and the papilla, enamel organ and periodontal ligament were removed with scalpel. The teeth were divided into three experimental groups: Group I , teeth immersed in 20 ml of physiologic saline; Group II , teeth immersed in 20 ml of 2% acidulated phosphate sodium fluoride; Group III , teeth immersed in 20 ml of 15% propolis. After 10 min of immersion in the solutions, the root canals were dried and filled with calcium hydroxide paste and the teeth were replanted. The animals were euthanized 60 days after replantation. The results showed that similar external root resorption was seen in the propolis and fluoride groups. Teeth treated with physiologic saline tended to have more inflammatory root resorption compared with those treated with fluoride or propolis. However, the comparative analysis did not reveal statistically significant differences (P > 0.05) between the treatment modalities when used for delayed tooth replantation. [source] Pulp revascularization of replanted immature dog teeth after treatment with minocycline and doxycycline assessed by laser Doppler flowmetry, radiography, and histologyDENTAL TRAUMATOLOGY, Issue 2 2004Alessandra Luisa de Souza Ritter Abstract,,, This study investigated the effect of topical antibiotic treatment on pulp revascularization in replanted teeth. Thirty-four immature teeth were selected from three young dogs. Baseline radiographs and laser Doppler flowmetry (LDF) readings were obtained. Specimens were randomly divided into four groups: Thirty-eight teeth were extracted, kept dry for 5 min, and either (Group 1) covered with minocycline mixture (G1, n = 11), (Group 2) soaked in doxycycline (G2, n = 11), or (Group 3) soaked in saline (G3-negative control, n = 6), and replanted. Teeth in Group 4 were not extracted (positive control, n = 6). Postoperative radiographs and LDF readings were obtained for 2 months after replantation. After sacrifice, the jaws were collected and processed for light microscopy. Pre- and postreplantation LDF readings and radiographs, and histologic findings were analyzed to assess revascularization. Pulp revascularization occurred in 91% (G1), 73% (G2), and 33% (G3) of the specimens. In conclusion, minocycline facilitates pulp revascularization in replanted immature teeth after replantation. [source] Effects and distribution of the enamel matrix derivative Emdogain® in the periodontal tissues of rat molars transplanted to the abdominal wallDENTAL TRAUMATOLOGY, Issue 1 2002Yoshioki Hamamoto Abstract , The enamel matrix derivative Emdogain® (EMD) has been found to promote regeneration of lost periodontal tissues. We have studied the effects and distribution of EMD in the periodontal tissues of maxillary rat molars transplanted to a subcutaneous position in the abdominal wall. The molars were transplanted with or without EMD either immediately after extraction or after drying for 30 min. After 2 days, 1, 2 or 4 weeks the rats were killed and the teeth were examined by means of light microscopy and immunohistochemistry with anti-amelogenin antibodies. Teeth transplanted immediately after extraction showed formation of alveolar bone separated from the dental roots by a periodontal space, regardless of the use of EMD. Among the teeth that were transplanted with EMD after drying for 30 min, new alveolar bone was formed in five out of eight teeth after 2 and 4 weeks. None of the teeth that were dried for 30 min and transplanted without EMD showed alveolar bone formation. Only one tooth transplanted with EMD showed root resorption after drying, while resorption was noted in all teeth transplanted without EMD. All teeth that were transplanted with EMD and none of the teeth that were transplanted without EMD showed an immunohistochemical reaction for amelogenin. After 2 days, amelogenin was precipitated on all surfaces exposed at the transplantation procedure. Later, the immunoreactive material was redistributed to cells at the root surface, where it was still demonstrable after 4 weeks. In conclusion, EMD is accumulated in cells at the root surface and promotes regeneration of the periodontal tissues of the transplanted teeth. It also seems to promote healing of root resorption. [source] Factors affecting the time of onset of resorption in avulsed and replanted incisor teeth in childrenDENTAL TRAUMATOLOGY, Issue 5 2001M. Donaldson Abstract , Resorption is the main reason for loss of replanted teeth. The outcome examined in this study is the timing of the onset of resorption. The effect of dichotomised dry and wet time intervals as well as the presence of additional crown damage and of contamination were determined. Of 84 replanted teeth, 67.5% developed resorptions. Twenty-eight had detectable additional crown damage with a more rapid onset being seen in these cases (P=0.009). The critical limit for dry time was 15 min (P=0.038) and significant differences persisted for greater limits also. Serial analysis of the association between the time of onset of root resorption and dichotomised wet time variables failed to yield any significant associations. There was visible contamination detected in 32 teeth and these exhibited a more rapid onset of resorption than the other cases (P=0.030). Teeth with inflammatory root resorption (12.8%) had a more rapid onset of resorption than those that developed replacement resorption (54.7%) (P<0.001). It is concluded that the risk of early resorption is increased in teeth that have additional damage or have contamination, or are kept in dry conditions for longer than 15 min. [source] Efficacy of laser Doppler flowmetry for the diagnosis of revascularization of reimplanted immature dog teethDENTAL TRAUMATOLOGY, Issue 2 2001Kallaya Yanpiset Abstract , This study was performed to assess if laser Doppler flowmetry (LDF) is an improved method for the detection of revascularization of replanted teeth. Teeth were extracted and reimplanted under different experimental conditions. LDF readings were taken before extraction and weekly for 3 months. In control teeth, LDF baseline readings were taken and then repeated after the apical blood vessels were cut surgically. At the end of 3 months it was determined radiographically and histologically whether revascularization had occurred, i.e. vitality had returned. Results: LDF readings correctly predicted the pulp status (vital vs. non-vital) in 83.7% of the readings. 73.9% (17 of 23) were correct for the vital teeth and 95% (19 of 20) were correct for the non-vital teeth. Fisher's exact test (2-tail) indicated that there was no significant association between the efficacy of LDF and tooth type (P=0.166), although P2 was the least accurate tooth tested. Wilcoxon's matched-pair signed rank test demonstrated that in the revascularized (vital) teeth, the flux value between the baseline and week 2 dropped significantly (P=0.0001), increased significantly from week 2 to week 4 (P=0.0001) and then decreased steadily until week 12. However, at week 12 the flux was still significantly higher than at week 2 (P=0.010). In the teeth that failed to revascularize, the flux value dropped significantly by weeks 1 and 2 (P=0.004 and P=0.0001, respectively). Flux values did not increase from week 2. A Fast Fourier Transform (FFT) analysis confirmed a pulse of dominant frequency of 2 Hz in the teeth that returned to vitality and the lack thereof in those that stayed non-vital. One tooth in which the flux value evaluation indicated a non-vital tooth but the radiographic/histologic findings showed vital (false negative) possessed a pulse of dominant frequency and proved by this method to have successfully revascularized. [source] Approximal caries development in surfaces in contact with fluoride-releasing and non-fluoride-releasing restorative materials: an in situ studyEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 6 2007Áine M. Lennon This study investigated the effect of compomer on initial interproximal caries development. One-hundred and sixty cylindrical, and 40 semispherical, bovine enamel samples (control) were prepared, polished, and sterilized. Sixty semicircular samples were prepared from each of the compomer Dyract eXtra and the fluoride-free composite Spectrum TPH. Samples were stored in water and fluoridated twice daily for 28 d. A baseline quantitative light fluorescence (QLF) image was made of each cylindrical sample. Twenty volunteers received intra-oral appliances with eight sample chambers. Each wing contained 1 control sample and either 3 Dyract eXtra or 3 Spectrum TPH samples in contact with the enamel surface of a cylindrical enamel sample. Appliances were worn for 24 h a day for 28 d except during toothbrushing (twice daily) and placement in 10% sucrose solution (five times daily). A final QLF image was made after 28 d. Caries development was analyzed as the lesion area × mean fluorescence loss (,Q % mm2) between these and the baseline images using QLF subtract software. The median ,Q was significantly lower in the Dyract eXtra group (,6.1% mm2) than in the Spectrum TPH (,13.9% mm2, P , 0.001) or control (,11.4% mm2, P = 0.03) groups. Teeth in contact with the compomer developed less caries compared with controls. [source] Dental caries and salivary status in children with type 1 diabetes mellitus, related to the metabolic control of the diseaseEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 1 2006Jolanta Siudikiene The aim of this study was to investigate the relationship among type 1 diabetes mellitus, dental caries, and salivary status in children. The study comprised 68, 10,15-yr-old diabetics, and 68, age- and gender-matched non-diabetic controls. Diabetics were categorized into well-to-moderately controlled (HbA1c <,9.0%) and poorly controlled (HbA1c , 9.0%) groups. Caries was recorded by assessing lesion activity at non-cavitated and cavity levels. Teeth were examined visually for the presence of dental plaque. Saliva was analyzed for unstimulated and stimulated flow rates, buffer effect, mutans streptococci, lactobacilli, and yeasts. Diabetics had fewer caries and plaque, lower salivary flow rates and buffer effect, and more frequent growth of yeasts than their non-diabetic controls. Well-to-moderately controlled diabetics had fewer decayed surfaces and lower counts of mutans streptococci and yeasts than poorly controlled diabetics, but the level of metabolic control of diabetes had no influence on salivary flow rates and buffer effect. High caries levels in diabetics were significantly associated with age, plaque score, and decreased unstimulated salivary flow rate, but were not associated with the level of metabolic control of diabetes. High caries experience in this study population could be related to plaque accumulation and/or to changes in saliva induced by diabetes mellitus. [source] Surface characteristics of dentin experimentally exposed to hydrofluoric acidEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 4 2003Thomas Pioch The purpose of this study was to test the effect of hydrofluoric acid (HF) on the surface characteristics of dentin in vitro. Dentin was exposed in 50 human molars and divided into five groups according to different etching schedules: (i) no etching, (ii) 15 s HF, (iii) 15 s H3PO4, (iv) 15 s HF and 15 s H3PO4, (v) 15 s H3PO4 and 15 s HF. Teeth were examined under a scanning electron microscope equipped with energy-dispersive X-ray (EDX) or two layers of fluorescence-labeled primer followed by the composite were applied, and the teeth were sectioned and examined using confocal laser scanning microscopy (CLSM). With scanning electron microscopy, no openings of dentinal tubules were found in groups (i), (ii), and (iv). In group (v) only a few tubules were opened and in group (iii) the smear layer was completely removed and tubules appeared open. The EDX analysis revealed that fluoride was incorporated into the dentin surface when HF was used. With CLSM, distinct hybrid layers could be detected only in group (iii). In group (v) the hybrid layer appeared less established compared with group (iii). No dentin hybridization was found in groups (i), (ii), and (iv). It is concluded that HF has the ability to close the openings of dentin tubules which were opened due to etching by phosphoric acid and cannot dissolve the smear layer. [source] New visions of dental tissue research: Tooth development, chemistry, and structureEVOLUTIONARY ANTHROPOLOGY, Issue 5 2008Tanya M. Smith Abstract Teeth are one of the best preserved and most commonly recovered elements in primate fossil assemblages. Taxonomic, functional, and phylogenetic hypotheses often rely on dental characters, despite considerable evidence of homoplasy in tooth form and large variation in tooth size within and among primates.1,2 Recent studies have led to new areas of research centered on incremental tooth development, chemical composition, and internal structure. Due to rapid technological developments in imaging and elemental sampling, these new approaches have the potential to increase our understanding of developmental biology, including not only changes in the pace of growth and reproduction, but also our assessments of diets, migration patterns, environments, and taxonomy. The integration of these temporal, chemical, and structural approaches heralds a bright future for the role of dental tissue research in evolutionary anthropology. © 2008 Wiley-Liss, Inc. [source] Oral disease experience of older adults seeking oral health servicesGERODONTOLOGY, Issue 2 2010Kavita P. Ahluwalia doi:10.1111/j.1741-2358.2009.00311.x Oral disease experience of older adults seeking oral health services Objective:, The objective of this investigation was to describe the dental disease (dental caries and alveolar bone loss) experience in a sample of community-dwelling older adults who regularly utilize dental services in New York City. Background:, Public financing for dental care directed at older adults in the United States is minimal. Improved preventive methods, primarily the use of fluorides, have resulted in declines in tooth loss, and concomitant increase in risk for dental diseases among older adults. While the oral disease burden in institutionalized elderly and those unable to access services is well-documented, the dental care needs of older adults who access dental services are not well documented. Materials and Methods:, Radiographic and record review were used to determine prevalence of dental caries, alveolar bone loss, frequency of service utilization, and medical status in this cross-sectional investigation of a sample of older adults (N = 200) using dental services at Columbia University College of Dental Medicine. Results:, Only 9% of the sample was completely edentulous, the mean DMFT was 19.9 and mean alveolar bone loss was 3.6 mm. Missing and Decayed Teeth accounted for 57.8% and 6.5% of the total caries burden respectively. Missing Teeth and alveolar bone loss increased with increasing age, but there was no increase in Decayed Teeth. Conclusions:, While access to and utilization of dental services may result in improved tooth retention, older adults who use dental services continue to have dental care needs, especially periodontal care needs. [source] Bonding acrylic teeth to acrylic resin denture bases: a reviewGERODONTOLOGY, Issue 3 2006S. B. Patil Partial or complete dentures are more commonly constructed for the elderly group of the population. Teeth debonding from the dentures can be frustrating to the patients as well as the dentist. Research has been carried out and is continuing to study the issue of bonding acrylic teeth to the denture base resin. The present review takes into account the majority of research papers published in the last five decades for determining the bond strength. Selection of more compatible combinations of denture base resins and acrylic teeth may reduce the number of prosthesis fractures and the resultant repairs. [source] Periodontal status and IOTN interventions among young hemophiliacsHAEMOPHILIA, Issue 4 2006S. AZHAR Summary., ,Fifty-two young individuals suffering from severe haemophilia A and B volunteered to be compared with school- and college-going students for oral health status description and subsequent management. A total of 244 students (84.42% boys and 15.58% girls) with the age group of 13,23 years were divided into two groups, A and B (controls). The purpose of this study was to increase awareness about evidence-based dental practices by oral examinations followed by comparisons of periodontal health and prevalence of malocclusions among medically compromised students and healthy controls. Results described the oral health in severe haemophilic population to be compromised with combined simplified health index score of 0.50 and Decayed/Modified/Filled Teeth (DMFT) index score of 2.07 when compared with 0.42 and 0.95, respectively, among group B. Although prevalence of malocclusion and orthodontic treatment needs among group A were higher, yet it was not confirmed as a reason for degraded dental and periodontal status. However, spontaneous and/or toothbrush (trauma)-induced gingival bleeding episodes among group A could be explained as factors discouraging oral hygiene maintenance, particularly self-administered measures. Four haemophiliacs presented with symptoms of Temporomandibular Joint Dysfunction Syndrome (TMPDS). Evidence-based oral medicine and clinical practices need to be encouraged and applied to enhance the quality of life among haemophiliacs, particularly in developing world. Dental treatment needs of haemophilic population appear to be greater and maybe incorporated in routine dental practices, at institutional and individual levels. [source] Do pre-irradiation dental extractions reduce the risk of osteoradionecrosis of the mandible?HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 6 2007Daniel T. Chang MD Abstract Background. This study was done to determine if pre-radiotherapy (pre-RT) dental extractions reduce the risk of osteoradionecrosis (ORN). Methods. Between 1987 and 2004, 413 patients with oropharyngeal carcinomas were treated with definitive RT at the University of Florida. Dentate patients underwent pretreatment dental evaluation. Teeth in the RT field were usually extracted if thought to have poor long-term prognosis from dental disease. The endpoint was ,grade 2 ORN using a modified staging system. Patients were excluded for local recurrence, additional RT above the clavicles, or head and neck surgery besides neck dissection. Results. ORN rates were as follows: edentulous, <1%; teeth in-field with pre-RT extractions, 15%; and teeth in-field without pre-RT extractions, 9%. Patients with poor in-field teeth and pre-RT extractions had a higher 5-year incidence of ORN than those who did not have pre-RT extractions (16% vs 6%, p = .48). Likewise, for those with in-field teeth in good condition and pre-RT extractions, the 5-year ORN incidence was higher than for those who did not undergo extractions (15% vs 2%, p = .42). Multivariate analysis revealed increased ORN risk with doses of >70 Gy, once-daily fractionation, or brachytherapy. Conclusion. Pre-RT extractions do not appear to reduce the risk of ORN. © 2007 Wiley Periodicals, Inc. Head Neck, 2007 [source] Influence of endodontic treatment, post insertion, and ceramic restoration on the fracture resistance of maxillary premolarsINTERNATIONAL ENDODONTIC JOURNAL, Issue 6 2010K. Bitter Bitter K, Meyer-Lueckel H, Fotiadis N, Blunck U, Neumann K, Kielbassa AM, Paris S. Influence of endodontic treatment, post insertion, and ceramic restoration on the fracture resistance of maxillary premolars. International Endodontic Journal, 43, 469,477, 2010. Abstract Aim, To investigate the effects of endodontic treatment, post placement and ceramic restoration type on the fracture resistance of premolars. Methodology, One hundred and twenty teeth maxillary premolars were allocated to four groups (A,D; n = 30). In group A, mesio-occlusal-distal-inlays with a buccal and palatal wall of 2 mm (MOD), in group B partial onlays with palatal cusp coverage and in group C total onlays with buccal and palatal cusp coverage were prepared. Group D served as untreated controls. Groups A,C were divided into three subgroups (n = 10): (i) teeth received solely the described preparations, (ii) teeth were root filled, (iii) teeth were root filled and quartz fibre posts were placed. Teeth were restored using Computer-assisted design/computer-assisted machining-ceramic-restorations and subjected to thermo-mechanical-loading; subsequently, the buccal cusp was loaded until fracture. Results, Group D revealed significantly higher fracture resistance [mean (standard deviation)] [738 (272) N] compared to all other groups (P < 0.05; post hoc test Dunnett). For groups A,C, fracture resistance was significantly affected by the restoration type (P = 0.043) and endodontic treatment/post placement (P = 0.039; 2-way anova). Group A [380 (146) N] showed significantly lower fracture resistance compared to group B [470 (158) N] (P = 0.048; post hoc test Tukey). Compared to non-endodontically treated teeth [487 (120) N], root filled teeth revealed significantly lower fracture resistance [389 (171) N] (P = 0.031). Conclusion, The restoration of cavities with a remaining wall thickness of 2 mm using ceramic MOD-inlays is inferior with respect to the fracture resistance compared to partial onlay restorations. Root filled teeth without post placement show lower fracture resistance compared to non-endodontically treated teeth. [source] The effect of irrigation time, root morphology and dentine thickness on tooth surface strain when using 5% sodium hypochlorite and 17% EDTAINTERNATIONAL ENDODONTIC JOURNAL, Issue 3 2010O. E. Sobhani Sobhani OE, Gulabivala K, Knowles JC, Ng Y-L. The effect of irrigation time, root morphology and dentine thickness on tooth surface strain when using 5% sodium hypochlorite and 17% EDTA. International Endodontic Journal, 43, 190,199, 2010. Abstract Aim, To evaluate the effect of irrigation with 5% sodium hypochlorite (NaOCl) alone and in conjunction with 17% ethylenediaminetetraacetic acid (EDTA) on tooth surface strain (TSS) and to analyse the influence of irrigation time, root morphology and dentine thickness. Methodology, Thirty-six single-rooted pre-molars with single canals had their crown and enamel reduced and root canals prepared using a standardized protocol. Teeth were grouped according to anatomical criteria and randomly distributed to experimental irrigation groups: (A) saline (negative control); (B) 5% NaOCl (positive control); (C) 5% NaOCl alternated with 17% EDTA. TSS was measured using electrical strain gauges bonded to the cervico-proximal part of the tooth. Teeth, mounted in clear acrylic resin placed in a universal testing machine, were subjected to nine consecutive 10-min irrigation periods followed by non-destructive occlusal loading to record TSS. Statistical analysis was carried out using two-way hierarchical anova and post hoc multiple comparisons. Results, Two groups showed an increase in TSS from the baseline (initial 10-min irrigation with saline). Group A showed a negligible reduction of 1.2% (343,339 ,,), which was not statistically significant (P = 0.7). Group B showed a highly significant (P = 0.001) increase in TSS by 53.7% (178,253 ,,), and group C showed a significant (P = 0.02) increase in TSS by 17.4% (163,192 ,,). The rate of change in TSS was significantly different between test groups. The length of the tooth (P = 0.04) as well as the mesio-distal (P = 0.05) width had significant effects on TSS. Conclusions, Irrigation with 5% with or without 17% EDTA increased TSS. The increase was significantly greater with 5% NaOCl alone than with 5% NaOCl alternated with 17% EDTA in contrast to previous findings with longer duration of irrigant exposure. Tooth length and mesio-distal root width significantly contributed to the increase in TSS. [source] Micro-computed tomography of tooth tissue volume changes following endodontic procedures and post space preparationINTERNATIONAL ENDODONTIC JOURNAL, Issue 12 2009O. H. Ikram Abstract Aim, To compare the volume of hard tooth tissue lost after caries removal, access cavity preparation, root canal preparation, fibre post space and cast post preparation in carious premolar teeth. The null hypothesis tested was that there is no difference between the volumes of hard tooth tissue lost expressed as a percentage of the preoperative hard tooth tissue volume, after each operative procedure. Methodology, Twelve extracted human premolars with mesial or distal carious cavities penetrating into the pulp chamber were selected. Teeth were scanned using a microCT scanner. After each operative procedure the loss of hard tooth tissue volume was measured. The data were statistically analysed using one-way analysis of variance and Fisher's PLSD test with statistical significance set at , = 0.01. Results, The percentage of preoperative hard tooth tissue volume lost after caries removal was 8.3 ± 5.83, after access cavity preparation the loss of volume reached 12.7 ± 6.7% (increase of 4.4%). After root canal preparation, fibre post space and cast post preparation the hard tissue volume lost reached, 13.7 ± 6.7 (increase of 1%), 15.1 ± 6.3 (increase of 1.4%) and 19.2 ± 7.4 (increase of 4.1%) respectively. Each procedure performed after caries removal significantly increased (P < 0.01) the amount of hard tissue volume lost with the exception of the root canal preparation. Conclusions, Access cavity and post space preparation are the procedures during root canal treatment which result in the largest loss of hard tooth tissue structure. Cast post space preparation causes a larger loss of tooth structure than fibre post space preparation. This should be taken into account when planning root canal treatment and restoration of root filled teeth that are to be restored with cuspal coverage restorations. [source] Effectiveness of HERO 642 versus Hedström files for removing gutta-percha fillings in curved root canals: an ex vivo studyINTERNATIONAL ENDODONTIC JOURNAL, Issue 11 2009B. Ayd Abstract Aim, To compare the effectiveness of gutta-percha removal and the maintenance of canal anatomy when using the HERO 642 system or Hedström files (H-files) in mandibular molar teeth. Methodology, The root canals of 40 mandibular molar teeth were instrumented using H-files and filled with gutta-percha and sealer. After 1 year in storage, the roots were sectioned horizontally to provide apical, middle and coronal root thirds. Sections were photographed, and an individual muffle was produced for each tooth. Teeth were randomly divided into four groups (n = 10) and the gutta-percha removed using either the HERO 642 system or H-files, with or without solvent. Digital images of the root canals were then re-taken. Root thirds were inspected for lateral perforations, and the percentage of the residual canal filling was determined on postoperative images. Transportation and centring ratio were calculated using preoperative and postoperative images of the cross-sections of root thirds. Results, H-files groups were associated with less filling material than the HERO 642 system (H-files,HERO 642 P = 0.056, H-files,HERO 642+solvent P = 0.041, H-files + solvent,HERO 642 P = 0.018, H-files + solvent,HERO 642 + solvent P = 0.016). The percentage of residual filling material was similar in the apical thirds, and the contribution of solvent to canal debridement was not statistically significant (P > 0.05). Perforation occurred mesiobuccally in 48% of specimens in the apical sections of mesial roots. There were no significant differences for centring ratio, transportation and perforation rate between groups. Conclusions, H-files left less gutta-percha overall; however, there was no difference in the apical third. The effect of solvent was not remarkable. Both instrument systems created a large number of perforations. [source] Influence of intracoronal bleaching agents on the ultimate strength and ultrastructure morphology of dentineINTERNATIONAL ENDODONTIC JOURNAL, Issue 7 2009V. Cavalli Abstract Objective, To evaluate the effects of intracoronal bleaching on ultimate tensile strength (UTS) of sound and etched dentine and its ultrastructure morphology. Methodology, Bovine dentine specimens with (e) or without previous etching with 37% phosphoric acid for 15 s were used for the intracoronal bleaching experiments. Teeth were randomly assigned to five treatments (n = 10): (C) control , no bleaching, (SP) sodium perborate, (CP) 35% carbamide peroxide, (25% HP) 25% hydrogen peroxide and (35% HP) 35% hydrogen peroxide. Bleaching was performed four times within a 72 h interval and afterwards, dentine pulp chamber blocks were obtained. The blocks were sectioned in 0.7 mm-thick slices and these were trimmed to reduce the inner dentine to a dumbbell shape with a cross-sectional area of 0.8 mm2. Specimens were tested with the microtensile method (0.5 mm min,1) and data were analysed (two-way anova -Tukey test, P < 0.05). Additional teeth were prepared for transmission electron microscopy (TEM) to evaluate dentine ultramorphology. Results, The mean values of the UTS (SD) in MPa for sound dentine were: C = 48.3(8.5)a, SP = 34.6 (8.2)b, CP = 32.9 (8.9)b, 25% HP = 28.0(4.6)b, 35% HP = 26.4(6.6)b, and pre-etched dentine: Ce = 38.9(13.8)a, SPe = 31.3 (9.3)ab, CPe = 28.4 (6.2)ab, 25% HPe = 30.0 (7.9)ab, 35% HPe = 19.9(4.6)b. Significant differences between the means are indicated by the letters. TEM observations exhibited demineralization areas for all bleaching treatments. Conclusion, Bleaching decreased dentine UTS after treatment. Pre-etched not-bleached dentine (Ce) presented UTS similar to pre-etched bleached dentine, except for 35% HPe. The decrease of UTS of bleached dentine could be attributed to ultrastructural alterations such as loss of inorganic components. [source] Randomized clinical trial of root-end resection followed by root-end filling with mineral trioxide aggregate or smoothing of the orthograde gutta-percha root filling , 1-year follow-upINTERNATIONAL ENDODONTIC JOURNAL, Issue 2 2009R. Christiansen Abstract Aim, To compare healing after root-end resection with a root-end filling of mineral trioxide aggregate (MTA) or smoothing of the orthograde gutta-percha (GP) root filling. Methodology, Forty-four patients (consisting of 52 teeth with periapical infection), average age of 54.6 years (range 30,77) participated in a randomized clinical trial (RCT) comparing the MTA and GP treatment methods. Radiographs produced 1-week and 12 months post-operatively were compared after blinding for treatment method, and healing was assessed as complete, incomplete, uncertain, or unsatisfactory. Results, Six teeth were not available for the 12-month follow-up: three teeth (GP) had been re-operated because of pain and two teeth (one GP, one MTA) had been extracted because of root fracture (these five teeth were classified as failures). One patient (GP) was not available for recall. In the GP group, seven teeth (28%) showed complete healing, six teeth (24%) incomplete healing, six teeth (24%) uncertain healing and two teeth (8%) unsatisfactory healing after 1 year. In the MTA group, 22 teeth (85%) showed complete healing, three teeth (12%) incomplete healing, and none were scored as uncertain or unsatisfactory healing after 1 year. The difference in healing between the GP and the MTA groups was significant (P < 0.001). Conclusions, The results from this RCT emphasize the importance of placing a root-end filling after root-end resection. Teeth treated with MTA had significantly better healing (96%) than teeth treated by smoothing of the orthograde GP root filling only (52%). [source] Efficacy of ProTaper Universal rotary retreatment system for gutta-percha removal from root canalsINTERNATIONAL ENDODONTIC JOURNAL, Issue 4 2008L.-S. Gu Abstract Aim, To evaluate the efficacy of the ProTaper Universal rotary retreatment system for gutta-percha (GP) removal from root canals. Methodology, Root canals of 60 extracted human maxillary anterior teeth were prepared and filled with laterally condensed GP and AH Plus sealer. Teeth were divided into three groups: group A , GP removal completed with the ProTaper Universal rotary retreatment system and with further canal repreparation accomplished with ProTaper Universal rotary instruments; group B , GP removal was completed using Gates Glidden drills and Hedström files with chloroform as a solvent, followed with further canal repreparation with ProTaper Universal rotary instruments; group C , the same as group B for GP removal with further canal preparation with stainless steel K-flex files (Kerr). The operating time was recorded. Teeth were rendered transparent for the evaluation of the area of remaining GP/sealer in bucco-lingual and mesial,distal directions. Statistical analysis was performed by using repeated measures analysis of variance and anova. Results, The ProTaper Universal technique (group A) resulted in a smaller percentage of canal area covered by residual GP/sealer than in groups B and C, with a significant difference between groups A and C (P < 0.05). Mean operating time for group A was 6.73 min, which was significantly shorter (P < 0.05) than group B (10.86 min) and group C (13.52 min). Conclusions, In this laboratory study all test techniques left GP/sealer remnants within the root canal. The ProTaper Universal rotary retreatment system proved to be an efficient method of removing GP and sealer from maxillary anterior teeth. [source] Root and canal morphology of maxillary first and second permanent molar teeth in a Ugandan populationINTERNATIONAL ENDODONTIC JOURNAL, Issue 9 2007C. M. Rwenyonyi Abstract Aim, To investigate the root and canal morphology of permanent maxillary molar teeth from a Ugandan population. Methodology, Maxillary first (n = 221) and second molar (n = 221) teeth were collected from patients attending dental clinics in Kampala. Teeth were prepared using a clearing technique: the pulp chambers were accessed and the teeth placed consecutively into 5% sodium hypochlorite, 10% nitric acid, then methyl salicylate. Indian ink was injected into the pulp chambers to demonstrate the canal system. Results, In the first molars, 95.9% of the teeth had separate roots. The mesiobuccal root was fused with the palatal root in 3% of specimens and with the distobuccal root in 0.5% of teeth. In the second molars, 86% of the teeth had separate roots. The mesiobuccal root was fused with the palatal root in 6.3% of specimens and with the distobuccal root in 6.8% of teeth. Apical deltas were more frequent in the mesiobuccal root when compared with distobuccal and palatal roots of both the first and second molars. A type I canal configuration (>75%) was the most frequent in all the roots of both the first and second molars. Canal intercommunications and lateral canals were more frequent in the mesiobuccal root when compared with other roots. Conclusions, The mesiobuccal root tended to have more variations in the canal system followed by the distobuccal root, whereas the palatal root had the least. The findings in root and canal morphology of this Ugandan population were different from previous studies, which may partly be attributed to racial differences. [source] Radiological assessment of periapical status using the periapical index: comparison of periapical radiography and digital panoramic radiographyINTERNATIONAL ENDODONTIC JOURNAL, Issue 6 2007C. Ridao-Sacie Abstract Aim, To compare the use of periapical radiographs and digital panoramic images displayed on monitor and glossy paper in the assessment of the periapical status of the teeth using the periapical index (PAI). Methodology, A total of 86 subjects were examined. All participants underwent a full-mouth radiographic survey (14 periapical radiographs) and a panoramic radiography. The periapical status, using the PAI score, of all appraised teeth was assessed. Results, Periapical radiographs allowed the assessment of the periapical status of 87% of teeth using the PAI. On the contrary, digital radiography had a significantly reduced potential to allow assessment of the periapical status (P < 0.01). Only 57.6% and 34.1% of teeth could be appraised using digital panoramic images displayed on monitor and glossy paper respectively (P < 0.01). The total percentage of teeth with periapical pathosis was five fold higher when assessed with digital panoramic images displayed on glossy paper compared with periapical radiographs (P < 0.01). Conclusions, Teeth were best viewed on periapical radiographs except maxillary second and third molars, which were better viewed in orthopantomograms. Orthopantomograms on screen were scorable more often than when on printed images. Apical periodontitis was scored more often on paper than on screen, and more often on screen than in periapical radiographs. [source] | ||||||||||||||||||||||||||||||||||||||||||||||