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Third Molars (third + molar)

Distribution by Scientific Domains

Medical Sciences	84%

Kinds of Third Molars

human third molar

mandibular third molar

Terms modified by Third Molars

third molar extraction

third molar surgery

third molar tooth

Selected Abstracts

Third molar position following Bionator treatment

ORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 3 2000
Calogero Dolce
Third molar eruption is an unpredictable event. The position of the third molar continuously changes during development. The purpose of this study was to evaluate the influence of Bionator treatment on third molar position against an untreated control group. A Bionator is a loose-fitting intra-oral appliance that postures the mandible forward, thereby producing skeletal and dentoalveolar changes. Data were obtained from direct measurements of existing longitudinal panoramic radiographs taken during the course of a randomized study investigating Class II malocclusion treatment options. The following variables were analyzed: mandibular third molar depth in relation to the cemento-enamel junction of the second molar; anterior,posterior (A,P) position in relation to the anterior border of the ramus; and angulation registered at the functional occlusal plane. Analysis of variance and ordinal logistic regression were used to investigate relationships between the variables. Angulation of the third molars changed substantially with varying depths (p<0.0008) and A,P positions (p<0.0001), but did not appear to relate appreciably to dental age (p>0.5) or treatment condition (p>0.4). The A,P position was significantly correlated to dental age (p>0.004) and Bionator treatment (p<0.0001), whereas depth was marginally associated with dental age (p<0.07) and not influenced by Bionator treatment (p>0.5). Third molars adopt a position further anterior in relation to the ramus with Bionator treatment than they do in controls. As dental age increases, Bionator use appears to positively influence third molar position. [source]

Dislocation of an upper third molar into the maxillary sinus after a severe trauma: a case report

DENTAL TRAUMATOLOGY, Issue 3 2007
Heng-Xing Cai
Abstract , Dental injuries are common following facial trauma. This article presents a rare injury: the dislocation of a third molar into the maxillary sinus after complex mandibular and maxillary tuberosity fractures. The possible mechanism and clinical treatment are discussed. [source]

Effect of selected literature on dentists' decisions to remove asymptomatic, impacted lower third molars

EUROPEAN JOURNAL OF ORAL SCIENCES, Issue 1 2002
Wil J. M. Van Der Sanden
The aim of this study was to assess the effect of studying selected literature on dentists' decisions to remove asymptomatic, impacted lower third molars. A pre-test,post-test control group design was used. Given 36 patient cases, two groups of 16 general dental practitioners each were asked to assess the need for removal of asymptomatic impacted lower third molars. The cases were classified by three parameters: ,position of the third molar', ,impaction type', and ,patient age'. After studying selected literature on this subject by the intervention group, both groups were asked to assess the same cases again. Frequencies of decisions to remove the third molars were calculated. For each participant, tables were composed by crosstabulating the indication to remove a third molar with each of the three parameters. T -tests were used to test the significance of the difference between pre-test and post-test decisions. The overall number of indications to remove asymptomatic, impacted lower third molars decreased by 37% in the intervention group. In the control group, the difference between pre- and post-test was not statistically significant. It was concluded that the provision of selected literature significantly influences treatment decision making by dentists in a third molar decision task. [source]

Calcifying epithelial odontogenic (Pindborg) tumor with malignant transformation and metastatic spread

HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 8 2001
Michael J. Veness MB
Abstract Background Pindborg tumors (calcifying epithelial odontogenic tumors) are uncommon neoplasms of odontogenic origin most often located in the posterior mandible. First described in detail in 1955 by Pindborg, these tumors are considered benign but can be locally aggressive in nature, with recurrence rates of 10% to 15% reported. The malignant form of this tumor is exceedingly rare. Methods We describe the case of a 64-year-old woman initially treated for a painful infected left mandibular third molar. The patient underwent extraction of the tooth and excision of an associated soft tissue component. Subsequent histologic review identified a Pindborg tumor of the left posterior mandible. Results After initial excision, this tumor recurred twice, with the recurrences exhibiting a progression to a malignant Pindborg tumor (odontogenic carcinoma) with vascular invasion and spread to a cervical lymph node. Further treatment involved radical surgery and adjuvant radiotherapy. At last review 12 months after treatment, the patient was disease free. Conclusions This article describes only the second case of odontogenic carcinoma. The transformation from benign to malignant histologic findings has not previously been documented in this tumor. The salient clinical features of this case are presented along with supportive pathologic and radiologic evidence. © 2001 John Wiley & Sons, Inc. Head Neck 23: 692,696, 2001. [source]

Leukaemic infiltration of the mandible in a young girl

INTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 2 2007
RACHAEL E. BENSON
Background., This report presents a case of leukaemic infiltration of the mandible in a 10-year-old female of Sudanese extraction. Case report., The patient was in remission from acute lymphoblastic leukaemia when she presented with pain localized to the alveolar ridge overlying the unerupted lower right second permanent molar. Two days later, she developed right inferior alveolar nerve paraesthesia. Radiographic imaging demonstrated cortical line absence around the developing lower right second and third permanent molars, and distal displacement of the lower right third molar. In addition, the cortical outline of the right inferior dental canal lacked clarity. Biopsy confirmed leukaemia recurrence demonstrating the Philadelphia chromosome. Tailored chemotherapy was commenced, and a bone marrow transplant was carried out 12 weeks later. At 6-month dental review, the patient remained exceptionally well with no bone pain and normal sensation in the right lower lip. Conclusion., The importance of regular and long-term dental examination of patients with leukaemia is discussed. [source]

Third molar position following Bionator treatment

Brief communication: The London atlas of human tooth development and eruption

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2010
S.J. AlQahtani
Abstract The aim of this study was to develop a comprehensive evidence-based atlas to estimate age using both tooth development and alveolar eruption for human individuals between 28 weeks in utero and 23 years. This was a cross-sectional, retrospective study of archived material with the sample aged 2 years and older having a uniform age and sex distribution. Developing teeth from 72 prenatal and 104 postnatal skeletal remains of known age-at-death were examined from collections held at the Royal College of Surgeons of England and the Natural History Museum, London, UK (M 91, F 72, unknown sex 13). Data were also collected from dental radiographs of living individuals (M 264, F 264). Median stage for tooth development and eruption for all age categories was used to construct the atlas. Tooth development was determined according to Moorrees et al. (J Dent Res 42 (1963a) 490,502; Am J Phys Anthropol 21 (1963b) 205,213) and eruption was assessed relative to the alveolar bone level. Intraexaminer reproducibility calculated using Kappa on 150 teeth was 0.90 for 15 skeletal remains of age <2 years, and 0.81 from 605 teeth (50 radiographs). Age categories were monthly in the last trimester, 2 weeks perinatally, 3-month intervals during the first year, and at every year thereafter. Results show that tooth formation is least variable in infancy and most variable after the age of 16 years for the development of the third molar. Am J Phys Anthropol, 2010. © 2010 Wiley-Liss, Inc. [source]

Variations in the mechanical properties of Alouatta palliata molar enamel

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 1 2010
Laura A. Darnell
Abstract Teeth have provided insights into many topics including primate diet, paleobiology, and evolution, due to the fact that they are largely composed of inorganic materials and may remain intact long after an animal is deceased. Previous studies have reported that the mechanical properties, chemistry, and microstructure of human enamel vary with location. This study uses nanoindentation to map out the mechanical properties of Alouatta palliata molar enamel on an axial cross-section of an unworn permanent third molar, a worn permanent first molar, and a worn deciduous first molar. Variations were then correlated with changes in microstructure and chemistry using scanning electron microscopy and electron microprobe techniques. The hardness and Young's modulus varied with location throughout the cross-sections from the occlusal surface to the dentin-enamel junction (DEJ), from the buccal to lingual sides, and also from one tooth to another. These changes in mechanical properties correlated with changes in the organic content of the tooth, which was shown to increase from ,6% near the occlusal surface to ,20% just before the DEJ. Compared to human enamel, the Alouatta enamel showed similar microstructures, chemical constituents, and magnitudes of mechanical properties, but showed less variation in hardness and Young's modulus, despite the very different diet of this species. Am J Phys Anthropol 2010. © 2009 Wiley-Liss, Inc. [source]

Brief communication: Dental development and enamel thickness in the Lakonis Neanderthal molar

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 1 2009
T.M. Smith
Abstract Developmental and structural affinities between modern human and Neanderthal dental remains continue to be a subject of debate as well as their utility for informing assessments of life history and taxonomy. Excavation of the Middle Paleolithic cave site Lakonis in southern Greece has yielded a lower third molar (LKH 1). Here, we detail the crown development and enamel thickness of the distal cusps of the LKH 1 specimen, which has been classified as a Neanderthal based on the presence of an anterior fovea and mid-trigonid crest. Crown formation was determined using standard histological techniques, and enamel thickness was measured from a virtual plane of section. Developmental differences include thinner cuspal enamel and a lower periodicity than modern humans. Crown formation in the LKH 1 hypoconid is estimated to be 2.6,2.7 years, which is shorter than modern human times. The LKH 1 hypoconid also shows a more rapid overall crown extension rate than modern humans. Relative enamel thickness was approximately half that of a modern human sample mean; enamel on the distal cusps of modern human third molars is extremely thick in absolute and relative terms. These findings are consistent with recent studies that demonstrate differences in crown development, tissue proportions, and enamel thickness between Neanderthals and modern humans. Although overlap in some developmental variables may be found, the results of this and other studies suggest that Neanderthal molars formed in shorter periods of time than modern humans, due in part to thinner enamel and faster crown extension rates. Am J Phys Anthropol, 2009. © 2008 Wiley-Liss, Inc. [source]

A cranial base of Australopithecus robustus from the hanging remnant of Swartkrans, South Africa

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2006
Darryl J. de Ruiter
Abstract SKW 18, a partial hominin cranium recovered from the site of Swartkrans, South Africa, in 1968 is described. It is derived from ex situ breccia of the Hanging Remnant of Member 1, dated to approximately 1.5,1.8 Mya. Although partially encased in breccia, it was refit to the facial fragment SK 52 (Clarke 1977 The Cranium of the Swartkrans Hominid SK 847 and Its Relevance to Human Origins, Ph.D. dissertation, University of the Witwatersrand, Johannesburg), producing the composite cranium SKW 18/SK 52. Subsequent preparation revealed the most complete cranial base attributable to the species Australopithecus robustus. SKW 18 suffered weathering and slight postdepositional distortion, but retains considerable anatomical detail. The composite cranium most likely represents a large, subadult male, based on the incomplete fusion of the spheno-occipital synchondrosis; unerupted third molar; pronounced development of muscular insertions; and large teeth. Cranial base measures of SKW 18 expand the range of values previously recorded for A. robustus. SKW 18 provides information on anatomical features not previously visible in this taxon, and expands our knowledge of morphological variability recognizable in the cranial base. Morphological heterogeneity in the development of the prevertebral and nuchal muscular insertions is likely the result of sexual dimorphism in A. robustus, while differences in cranial base angles and the development of the occipital/marginal sinus drainage system cannot be attributed to size dimorphism. Am J Phys Anthropol, 2006. © 2006 Wiley-Liss, Inc. [source]

An unusual presentation of an ectopic third molar in the condylar region

AUSTRALIAN DENTAL JOURNAL, Issue 3 2010
C Pace
Abstract We describe the case of a 53-year-old patient who presented with an intermittent discharging sinus on his face which, following a number of investigations, was found to be secondary to an ectopic third molar in the condylar region. The ectopic tooth was surgically removed with complete resolution of the facial swelling. This case highlights the possibility of dental pathology presenting with completely unrelated signs and symptoms, and the importance of the clinician maintaining an open mind when it comes to the differential diagnosis of such a presentation. [source]

The use of vein grafts in the repair of the inferior alveolar nerve following surgery

AUSTRALIAN DENTAL JOURNAL, Issue 2 2010
RHB Jones
Abstract Damage to the branches of the trigeminal nerve can occur as a result of a variety of causes. The most common damage to all divisions of this nerve occurs as a result of facial trauma. Unfortunately, iatrogenic damage to the inferior alveolar branch of the mandibular division of the trigeminal nerve is common because of its anatomical position within the mandible and its closeness to the teeth, particularly the third molar. It has been reported there is an incidence of approximately 0.5% of permanent damage to the inferior alveolar nerve following third molar removal. Extraction of other teeth within the mandible carries a lower incidence of permanent damage. However, damage can still occur in the premolar area, where the nerve exits the mandible via the mental foramen. Dental implants are a relatively new but increasing cause of damage to this nerve, particularly if the preoperative planning is inadequate. CT scanning is important for planning the placement of implants if this damage is to be reduced. Primary repair of the damaged nerve will offer the best chance of recovery. However, if there is a gap, and the nerve ends cannot be approximated without tension, a graft is required. Traditionally, nerve grafts have been used for this purpose but other conduits have also been used, including vein grafts. This article demonstrates the use of vein grafts in the reconstruction of the inferior dental branch of the mandibular division of the trigeminal nerve following injury, in this case due to difficulty in third molar removal, following sagittal split osteotomy and during the removal of a benign tumour from the mandible. In the five cases presented, this technique has demonstrated good success, with an acceptable return of function occurring in most patients. [source]

Endodontic management of a fused mandibular third molar and distomolar: A case report

AUSTRALIAN ENDODONTIC JOURNAL, Issue 1 2010
Ali Zeylabi dds
Abstract Careful management of fused teeth is essential as abnormal morphology can predispose a tooth to caries and periodontal disease. In this paper, a rare case of successful endodontic management of unilateral mandibular third molar fused to a distomolar is reported. Caries was removed from the tooth complex under local anaesthesia. The pulp chambers of the third molar and supernumerary tooth were accessed and the root canals were prepared using rotary instrumentation and copious irrigation with 2.5% sodium hypochlorite. Obturation using the lateral condensation technique with gutta-percha and AH26 sealer was subsequently performed. A 1-year recall showed a good treatment result. [source]

Effect of selected literature on dentists' decisions to remove asymptomatic, impacted lower third molars

Dentin surface treatment using a non-thermal argon plasma brush for interfacial bonding improvement in composite restoration

EUROPEAN JOURNAL OF ORAL SCIENCES, Issue 5 2010
Andy C. Ritts
Ritts AC, Li H, Yu Q, Xu C, Yao X, Hong L, Wang Y. Dentin surface treatment using a non-thermal argon plasma brush for interfacial bonding improvement in composite restoration. Eur J Oral Sci 2010; 118: 510,516. © 2010 Eur J Oral Sci The objective of this study was to investigate the treatment effects of non-thermal atmospheric gas plasmas on dentin surfaces used for composite restoration. Extracted unerupted human third molars were prepared by removing the crowns and etching the exposed dentin surfaces with 35% phosphoric acid gel. The dentin surfaces were treated using a non-thermal atmospheric argon plasma brush for various periods of time. The molecular changes of the dentin surfaces were analyzed using Fourier transform infrared spectrophotometry/attenuated total reflectance (FTIR/ATR), and an increase in the amount of carbonyl groups was detected on plasma-treated dentin surfaces. Adper Single Bond Plus adhesive and Filtek Z250 dental composite were applied as directed. To evaluate the dentin/composite interfacial bonding, the teeth thus prepared were sectioned into micro-bars and analyzed using tensile testing. Student,Newman,Keuls tests showed that the bonding strength of the composite restoration to peripheral dentin was significantly increased (by 64%) after 30 s of plasma treatment. However, the bonding strength to plasma-treated inner dentin did not show any improvement. It was found that plasma treatment of the peripheral dentin surface for up to 100 s resulted in an increase in the interfacial bonding strength, while prolonged plasma treatment of dentin surfaces (e.g. 5 min) resulted in a decrease in the interfacial bonding strength. [source]

Effects of additional and extended acid etching on bonding to caries-affected dentine

EUROPEAN JOURNAL OF ORAL SCIENCES, Issue 5 2004
César Augusto Galvão Arrais
This study evaluated the effects of additional and extended acid etching on microtensile bond strength (µTBS) of two adhesive systems to sound (SD) and caries-affected dentine (CAD). Flat surfaces of CAD surrounded by SD of 36 extracted carious third molars were assigned to four treatments (i): self-etching adhesive system (Clearfil SE Bond) applied to dentine surfaces following manufacturer's instructions (MI); (ii) after additional etching for 15 s (35% phosphoric acid, PA); (iii) total-etch one-bottle adhesive (Single Bond) applied to dentine surfaces following MI; or (iv), after etching for 45 s with PA. Composite ,blocks' were built on bonded surfaces and restored teeth were vertically sectioned to obtain bonded slices of 0.7 mm thick. Slices were trimmed to create hourglass-shaped specimens (cross-sectional area of 1 mm2), which were tested under tension in a universal testing machine. Additional CAD and SD samples were prepared for scanning electron microscopy observations. Additional and extended etching significantly increased µTBS to CAD; however, µTBS of both adhesives to CAD were significantly lower than to SD. Additional and extended etching can improve bonding to CAD; however, adhesives applied on SD showed the best results for bonding. [source]

Effect of selected literature on dentists' decisions to remove asymptomatic, impacted lower third molars

Localization of substance P-induced upregulated interleukin-8 expression in human dental pulp explants

INTERNATIONAL ENDODONTIC JOURNAL, Issue 2 2008
G. T.-J.
Abstract Aim, To localize ex vivo expression of interleukin-8 (IL-8) induced by substance P (SP) in human dental pulps. Methodology, Intact caries-free, freshly extracted third molars (n = 20) were collected from patients (15,25 years old). The teeth were split and pulpal tissue was obtained and stored in Dulbecco's modified Eagle medium. Human dental pulp tissue explants were stimulated with SP. Expression of IL-8 in pulp explants was detected and localized by immunohistochemistry. Results, Moderated IL-8 immunoreactivities were detected mainly in the cell-rich zone in pulp tissues 12 h after tumour necrosis factor alpha (TNF-,) stimulation (positive controls), whereas only weak IL-8 expression was observed in tissues stimulated with SP at the same time interval. These data did not differ from those in negative controls. Increased IL-8 expression in pulp explants after 24 h of SP stimulation was noted compared with negative controls and located in fibroblast-like cells, blood vessel-associated cells and extracellular matrix in the central zone and cell-rich zone of pulp explants. Tissues stimulated with TNF-, for 24 h (positive controls) revealed weak IL-8 immunoreactivities with altered cell morphology. Conclusions, Substance P induces IL-8 expression and was located in fibroblast-like pulp cells, blood vessel-associated cells and extracellular matrix of human dental explants. These data support the hypothesis that neuropeptide (SP) coordinates the modulation of pulpal inflammation via up-regulating chemokine IL-8. [source]

Radiological assessment of periapical status using the periapical index: comparison of periapical radiography and digital panoramic radiography

INTERNATIONAL ENDODONTIC JOURNAL, Issue 6 2007
C. 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]

Influence of the pulpal components on human dentine permeability in vitro

INTERNATIONAL ENDODONTIC JOURNAL, Issue 3 2005
P. Puapichartdumrong
Abstract Aim, To examine the influence of the retained pulpal components on permeability of human dentine by monitoring drug diffusion. Methodology, Twelve intact dentine discs were prepared from freshly extracted human third molars. The dentine surface on the enamel side was etched with 10% polyacrylic acid for 30 s. The drug diffusion test was carried out before and after removal of the retained pulpal components. Each dentine disc was inserted between two plastic chambers; enamel- and pulpal-side chambers, which were filled with 0.05 mol L,1 naproxen sodium (NA) and phosphate-buffered saline (PBS), respectively. After 10 min, the solution on the pulpal-side chamber was collected to determine the concentration of NA using a spectrophotometer. To remove the retained pulpal components and residual NA, the pulp chamber of each disc was washed out with PBS and placed in an ultrasonic cleaner. After removal of these components and the residual NA, the drug diffusion test was repeated. The inner surface of the pulp chamber was observed using scanning electron microscopy (SEM) before and after the removal of the retained pulpal components. Results, The amount of NA that diffused through dentine into the pulp was significantly higher after the pulp chamber was washed out with PBS (paired t -test, P < 0.05). SEM observation demonstrated the presence of the retained pulpal components, odontoblastic layer and some parts of subodontoblastic zone, covering the surface of predentine. These components were removed after the pulp chamber was washed out with PBS followed by cleaning in an ultrasonic cleaner. Conclusions, The presence of retained pulpal components had a significant influence on drug diffusion through dentine discs. [source]

Periapical status and quality of root fillings and coronal restorations in an adult Spanish population

INTERNATIONAL ENDODONTIC JOURNAL, Issue 8 2004
J. J. Segura-Egea
Abstract Aim, To investigate the quality of root fillings and coronal restorations and their association with periapical status in an adult Spanish population. Methodology, A total of 180 subjects, aged 37.1 ± 15.7 years, who presented as new patients at the Faculty of Dentistry, Seville, Spain, were examined. All participants underwent a full-mouth radiographic survey incorporating 14 periapical radiographs. The periapical region of all root filled teeth, excluding third molars, were examined. The technical quality of root fillings was evaluated in terms of length in relation to the root apex and lateral adaptation to the canal wall. Radiographic signs of overhang or open margins associated with coronal restorations were also evaluated. Periapical status was assessed using the Periapical Index score. Statistical analyses were conducted using the Cohen's , test and logistic regression. Results, The total number of root filled teeth was 93, and 60 (64.5%) had apical periodontitis (AP). Presence of AP in root filled teeth was associated with inadequate adaptation of the filling (OR = 2.29; P = 0.06), inadequate length of the root filling (OR = 2.44; P = 0.048), and with poor radiographic quality of the coronal restoration (OR = 2.38; P = 0.054). Only 34.4% of the root fillings were adequate from a technical perspective. When both root fillings and coronal restorations were adequate the incidence of AP decreased to 31.3% (OR = 5.50; P < 0.01). Conclusions, The incidence of AP in root filled teeth was high. Many root fillings were technically unsatisfactory. Adequate root fillings and coronal restorations were associated with a lower incidence of AP; an adequate root filling had a more substantial impact on the outcome of treatment than the quality of the coronal restoration. [source]

Variations in number and morphology of permanent teeth in 7-year-old Swedish children

INTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 1 2001
B. Bäckman
Summary.Objectives. To establish the prevalence of numerical and morphological variations of permanent teeth in Swedish 7-year-olds and to accept or reject the hypothesis of a higher prevalence for these conditions in northern Sweden compared to other areas. Design. Cross-sectional. Setting. Department of Odontology/Pedodontics, Umeå University, Sweden. Sample and methods. A total of 739 healthy Caucasian 7-year-olds residing in the city of Umeå, northern Sweden in 1976. The children were examined clinically and radiographically. Results. The prevalence of hypodontia (excluding third molars) in girls was 8·4%, in boys 6·5%, and in both sexes combined 7·4%. Of the children with hypodontia, the majority (90·9%) lacked one or two teeth. Lower second premolars were the teeth most frequently missing. The prevalence of hyperdontia was 1·9%; 11 girls and three boys were affected; 78% of the supernumerary teeth were mesiodenses. Of the morphological variations, peg-shaped upper lateral incisors were found in 0·8% of the children, double-formation (gemination) in 0·3%, taurodontism in 0·3% and dens invaginatus in 6·8%. One diagnosis was found in 18% of the children, and in almost 8% of them more than one diagnosis was found. Conclusions. The results agree with those obtained in similar populations and are considered representative of this ethnic group. The hypothesis of a genetically determined higher prevalence of numerical and morphological variations in the study population was not verified. [source]

Effect of curing mode on bond strength of self-adhesive resin luting cements to dentin

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2010
T. R. Aguiar
Abstract In this study, the in vitro bond strength of dual-curing resin cements to indirect composite restorations when the cement was either light polymerized or allowed to only autopolymerize was evaluated. Occlusal dentin surfaces of 56 extracted human third molars were flattened to expose coronal dentin. Teeth were assigned to eight groups (n = 7) according to resin cement products and polymerization modes: conventional cement (Panavia F 2.0; Kuraray Medical) and self-adhesive cements [RelyX Unicem (3M ESPE), BisCem (Bisco), and G-Cem (GC Corp.)]. Cements were applied to prepolymerized resin discs (2-mm-thick Sinfony; 3M ESPE), which were subsequently bonded to the prepared dentin surfaces. The restored teeth were either light-polymerized through the overlying composite according to manufacturers' instructions or were allowed to only self-cure. After 24 h, the teeth and restorations were sectioned to obtain multiple bonded beams (1.0 mm2) and tested in tension at a crosshead speed of 0.5 mm/min until failure. Data (MPa) were analyzed by two-way ANOVA and Tukey test (, = 0.05). Light activation of some cement systems (G-Cem and Panavia F 2.0) increased the bond strength, while the curing mode did not affect the bond strength for some (RelyX Unicem and BisCem). The bond strength in the autopolymerized mode varied among products. In general, the use of self-adhesive resin cements did not provide significantly higher bond strengths than that of a conventional material, and two self-adhesive cements yielded significantly lower bond values (regardless of cure mode) than the other products. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010 [source]

Adhesion of a self-etching system to dental substrate prepared by Er:YAG laser or air abrasion

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2008
Wanessa C. Souza-Zaroni
Abstract The purpose of this study was to assess the microtensile bond strength of a self-etching adhesive system to enamel and dentin prepared by Er:YAG laser irradiation or air abrasion, as well as to evaluate the adhesive interfaces by scanning electron microscopy (SEM). For microtensile bond strength test, 80 third molars were randomly assigned to five groups: Group I, carbide bur, control (CB); II, air abrasion with standard tip (ST); III, air abrasion with supersonic tip (SP); IV, Er:YAG laser 250 mJ/4 Hz (L250); V, Er:YAG laser 300 mJ/4 Hz (L300). Each group was divided into two subgroups (n = 8) (enamel, E and dentin, D). E and D surfaces were treated with the self-etching system Adper Prompt L-Pop and composite buildups were done with Filtek Z-250. Sticks with a cross-sectional area of 0.8 mm2 (±0.2 mm2) were obtained and the bond strength tests were performed. Data were submitted to ANOVA and Tukey's test. For morphological analysis, disks of 30 third molars were restored, sectioned and prepared for SEM. Dentin presented the highest values of adhesion, differing from enamel. Laser and air-abrasion preparations were similar to enamel. Dentin air-abrasion with standard tip group showed higher bond strength results than Er:YAG-laser groups, however, air-abrasion and Er:YAG laser groups were similar to control group. SEM micrographs revealed that, for both enamel and dentin, the air-abrasion and laser preparations presented irregular adhesive interfaces, different from the ones prepared by rotary instrument. It was concluded that cavity preparations accomplished by both Er:YAG laser energies and air abrasion tips did not positively influence the adhesion to enamel and dentin. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008 [source]

Tooth loss in well-maintained patients with chronic periodontitis during long-term supportive therapy in Brazil

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 10 2006
Luiz A. Chambrone
Abstract Aim: The objective of this retrospective study was to assess the reasons for tooth loss in a sample of patients who underwent periodontal therapy and supportive periodontal therapy (SPT) in a Brazilian private periodontal practice. Material and Methods: A sample of 120 subjects who had been treated and maintained for 10 years or longer was selected from patients attending a periodontal practice. All patients followed a similar treatment: basic procedures, re-evaluation and periodontal surgery where indicated. Reasons for tooth loss were categorized as periodontal, caries, endodontal, root fractures and extraction of retained or partially erupted third molars. Results: Of the 2927 teeth present at the completion of active periodontal treatment, 53 (1.8%) were lost due to periodontal disease, 16 (0.5%) for root fracture, six (0.2%) to caries, five (0.2%) for endodontic reasons and 31 (1.0%) were lost to extraction of retained or partially erupted third molars. Logistic regression analysis was performed to investigate the association between five independent variables with tooth loss due to periodontitis. Only age (>60 years) and smoking were statistically significant (p<0.05). Conclusion: The findings of this survey were consistent with previous studies. Older subjects and smokers were more susceptible to periodontal tooth loss. In addition, patients with generalized chronic periodontitis were treated and maintained for long-term periods with low rates of tooth loss. [source]

Occurrence and risk indicators of increased probing depth in an adult Brazilian population

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 2 2005
Cristiano Susin
Abstract Background/Aims: There is little information about the occurrence and risk indicators for periodontal diseases in Latin America. The present study describes the prevalence, extent and severity of periodontal probing depth (PPD) and assesses the association between demographic, behavioural and environmental risk indicators and the extent and severity of PPD in this population. Materials and Methods: The target population was urban adults aged 30 years in Rio Grande do Sul state in South Brazil. A representative sample was selected using a multi-stage, probability, cluster sampling strategy and included 853 dentate subjects 30,103 years of age. A full-mouth clinical examination was carried out at six sites per tooth on all permanent teeth, excluding third molars, and was conducted in a mobile examination centre. Results: Approximately 65% and 25% of the subjects and 19% and 5% teeth per subject had PPD 5 and 7 mm, respectively. 31.6%, 33.7% and 34.7% subjects had generalized, localized or no PPD 5 mm, respectively. Probing depth increased in prevalence with increasing age, and leveled off at around 50 years of age and beyond. PPD 5 mm was significantly higher in males than in females, and in non-Whites than in Whites. Cigarette smokers had a significantly higher occurrence of PPD 5 mm than non-smokers, and this relationship was dose dependent. A multivariate model showed that generalized PPD 5 mm was associated with subjects aged 40 years, males, non-Whites and moderate or heavy cigarette smokers (relative risk ratios: 2.0, 2.0, 2.2, 2.4 and 6.8, respectively). Conclusion: Moderate and deep probing depth was a common finding in this urban adult Brazilian population. Older age, male gender, non-White race and moderate and heavy cigarette smoking were significant risk indicators of increased PPD, and these may be useful indicators of periodontal disease high-risk groups. [source]

Relationship of cigarette smoking to the subgingival microbiota

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 5 2001
A. D. Haffajee
Abstract Background: The relationship of cigarette smoking to the composition of the subgingival microbiota is not clear. Some studies indicated higher levels of certain species in smokers, while other studies failed to detect differences in the microbiota between subjects with different smoking histories. Thus, the purpose of the present investigation was to examine the prevalence, proportions and levels of the subgingival species in adult subjects who were current, past or never smokers. Method: 272 adult subjects ranging in age from 20,86 years with at least 20 teeth were recruited for study. Smoking history was obtained using a questionnaire. Clinical measures were taken at 6 sites per tooth at all teeth excluding third molars at a baseline visit. Subgingival plaque samples were taken from the mesial surface of all teeth excluding third molars in each subject at baseline and assayed individually for counts of 29 subgingival species using checkerboard DNA-DNA hybridization. Subjects were subset according to smoking history into never (n=124), past (n=98) and current smokers (n=50). Uni-variate and multi-variate analyses were used to seek associations between smoking category and the counts, proportions and prevalence of subgingival species. Results: Greater differences were observed for the prevalence (% of sites colonized) of the test species in the 3 smoking groups than were observed for counts or proportions of total counts. Members of the orange and red complexes including E. nodatum, F. nucleatum ss vincentii, P. intermedia, P. micros, P. nigrescens, B. forsythus, P. gingivalis and T. denticola were significantly more prevalent in current smokers than in the other 2 groups. The difference in prevalence between smokers and non-smokers was due to greater colonization at sites with pocket depth <4 mm. Stepwise multiple linear regression analysis indicated that combinations of the prevalence of 5 microbial species and pack years accounted for 44% of the variance for mean pocket depth (p<0.000001), while the prevalence of 3 microbial taxa along with age, pack years, current smoking and gender accounted for 31% of the variance in mean attachment level (p<0.000001). The difference in prevalence between current and never smokers of all members of the red complex and 8 of 12 members of the orange complex was significantly greater in the maxilla than in the mandible. Conclusions: The major difference between the subgingival microbiota in subjects with different smoking history was in the prevalence of species rather than counts or proportions. The greater extent of colonization in smokers appeared to be due to greater colonization at pocket depths <4 mm. Differences in colonization patterns between current and never smokers were greater in the maxilla than in the mandible. Zusammenfassung Grundlagen: Die Beziehung zwischen dem Zigarettenrauchen und der Zusammensetzung der subgingivalen Mikroflora ist nicht klar. Einige Studien verweisen auf höhere Titer von bestimmten Spezies bei Rauchern, während andere Studien keine Unterschiede in der Mikroflora zwischen Personen mit unterschiedlichem Raucher- oder Nichtraucherverhalten nachweisen konnten. Daher war der Zweck der vorliegenden Studie die Untersuchung von Prävalenz, Anteil und Titer der subgingivalen Spezies bei erwachsenen Patienten, die zur Zeit, früher oder niemals Raucher waren. Methode: Für die Studie wurden 272 erwachsene Patienten im Alter zwischen 20 und 86 Jahren und wenigstens 20 Zähnen rekrutiert. Die Anamnese des Rauchverhaltens wurde under Verwendung eines Fragebogens durchgeführt. Bei einer Eingangsuntersuchung erfolgten die klinischen Messungen an 6 Stellen pro Zahn bei allen Zähnen außer den dritten Molaren. Bei der Eingangsuntersuchung wurden, bei allen Zähnen außer den dritten Molaren, von den Mesialflächen subgingivale Plaqueproben entnommen. Für die einzelnen Flächen wurde die Anzahl von 29 subgingivalen Spezies mittels Schachbrett-DNA-DNA-Hybridisierung bestimmt. Die Patienten wurden entsprechend der Rauchervorgeschichte in folgende Gruppen eingeteilt: niemals (n=124), früher (n=98) und zur Zeit (n=50). Um Assoziationen zwischen den Rauchkategorien und der Anzahl, dem Anteil und der Prävalenz der subgingivalen Spezies herauszufinden wurden eine uni-variate und multi-variate Analyse verwendet. Ergebnisse: Es wurden größere Unterschiede zwischen den 3 Gruppen hinsichtlich der Prävalenz der Testspezies (% der Taschen die kolonisiert waren) beobachtet als bei der Anzahl oder dem Anteil an der Gesamtzahl der Keime beobachtet wurde. Die Prävalenz der Keime des orangen und roten Komplexes einschließlich. E. nodatum, F. nucleatum ss vincentii, P. intermedia, P. micros, P. nigrescens, B. forsythus, P. gingivalis und T. denticola war bei den aktuellen Rauchern stärker prävalent als in den anderen beiden Gruppen. Die Differenz in der Prävalenz zwischen Rauchern und Nichrauchern wurde verursacht durch eine stärkere Kolonisation in Taschen mit einer Taschentiefe <4 mm. Die schrittweise multiple lineare Regressionsanalyse zeigte, dass Kombinationen der Prävalenz von 5 mikrobiellen Spezies und der Packungsjahre für 44% der Varianz der mittleren Taschentiefe verantwortlich waren (p<0.000001), während die Prävalenz von 3 mikrobiellen Taxa zusammen mit Alter, Packungsjahre, Raucherstatus und Geschlecht für 31% der Varizna im mittleren Attachmentniveau verantwortlich waren (p<0.000001). Die Differenz in der Prävalenz zwischen den aktuellen Rauchern und den die niemals rauchten war für alle Keime der roten Komplexes und 8 von 12 Keimen des orangen Komplexes im Oberkiefer signifikant größer als im Unterkiefer. Schlussfolgerung: Der Hauptunterschied zwischen der subgingivalen Mikroflora bei Patienten mit unterschiedlicher Rauchervorgeschichte lag mehr bei der Prävalenz der Spezies als bei der Anzahl der Keime oder den Anteilen an der Gesamtflora. Das größere Maß an Kolonisation bei den Rauchern schien durch eine stärkere Kolonisation in Taschen <4 mm verursacht zu sein. Differenzen im Kolonisationsmuster zwischen aktuellen Rauchern und Nichtrauchern die niemals rauchten waren im Oberkiefer größer als im Unterkiefer. Résumé Origine, but: La relation entre l'usage de la cigarette et la composition de la microflore sous gingivale n'est pas claire. Certaines études indiquent d'importants niveaux de certaines espèces chez les fumeurs, alors que d'autres études n'arrivent pas à détecter de différences dans la micrflore entre des sujets ayant des histoires tabagiques différentes. Aussi, le propos de cette recherche est d'examiner la prévalence, les proportions et le niveau des espèces sous gingivales chez des sujets adultes fumeurs, anciens fumeurs ou non-fumeurs. Méthodes: 272 sujets adultes, âgès de 20 à 86 ans, ayant au moins 20 dents furent recrutés pour l'étude. L'histoire tabagique fut obtenue à l'aide d'un questionnaire. Des mesures cliniques furent prises sur 6 sites par dents, sur toutes les dents à l'exception des troisièmes molaires lors de la première visite. Des échantillons de plaque sous gingivale étaient prélevés sur la face mésiale de chaque dent à l'exception des troisièmes molaires chez chaque sujet lors de la première visite et individuellement testés pour le comptage de 29 espèces sousgingivales par hybridisation en damier ADN-ADN. Les sujets étaient groupés en sous ensembles en fonction de leur histoire tabagique en non-fumeurs (n=124), ancien fumeurs (n=98), et fumeurs (n=50). Des analyses monovariées et multivariées furent utilisées pour rechercher des associations entre les catégories de fumerus et les comptages, proportions et prévalences des espèces bactériennes. Résultats: De plus grandes différences étaient observées pour la prévalence (% de sites colonisés) des expèces testées dans les 3 groupes, que pour le comptage ou la proportion des comptages totaux. Les membres des complexes orange et rouge dont E. nodatum, F. nucléatum ss vicentii, P. intermedia, P. micros, P. nigrescens, B. forsythus, P. gingivalis, et T. denticolaétait significativement plus prévalent chez les fumeurs que dans les 2 autres groupes. La différence de prévalence entre les fumeurs et les non-fumeurs était due à une plus grande colonisation des sites dont la profondeur de poche était <4 mm. L'analyse par régression linéaire multiple stepwise indiquait que les combinaisons de la prévalence de 5 espèces microbiennes et les paquets-années comptaient pour 44% de la variance pour la moyenne de profondeur de poche (p<0.000001), alors que la prévalence de 3 taxons microbiens avec l'âge, les paquets-années, le tabagisme présent et le sexe comptaient pour 31% de la variance pour le niveau d'attache moyen (p<0.000001). La différence de prévalence entre les fumerus en activité et les non-fumeurs (jamais fumé) de tous les membres du complexe rouge et de 8 des 12 membres du complexe orange était significativement plus élevée au maxillaire qu'à la mandibule. Conclusions: La différence majeure entre les microflores sous gingivales chez les sujets ayant des histoires tabagiques différentes se trouvaient dans la prévalence des expèces plutôt que dans leurs quantité ou leurs proportions. La plus grande importance de colonisation chez les fumerus apparaît être dûe à une colonisation plus grande dans les poches <4 mm. Des différences des caractéristiques de colonisation entre les fumerus actifs et les personnes n'ayant jamais fuméétaient plus importantes au maxillaire qu'à la mandibule. [source]

The effect of repeated professional supragingival plaque removal on the composition of the supra- and subgingival microbiota

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 9 2000
Laurie Ann Ximénez-Fyvie
Abstract Background, aims: The purpose of the present investigation was to determine the effect of weekly professionally administered supragingival plaque removal on the composition of the supra and subgingival microbiota. Methods: 18 adult subjects with periodontitis who had been treated and were in a maintenance phase of therapy were clinically and microbiologically monitored at baseline, 3, 6 and 12 months. After the baseline visit, the subjects received scaling and root planing followed by professional supragingival plaque removal every week for 3 months. Clinical measures of plaque accumulation, bleeding on probing (BOP), gingival redness, suppuration, pocket depth and attachment level were made at 6 sites per tooth at each visit. Separate supra (N=1804) and subgingival (N=1804) plaque samples were taken from the mesial aspect of all teeth excluding third molars in each subject at each time point and evaluated for their content of 40 bacterial taxa using checkerboard DNA-DNA hybridization. Significance of changes in mean counts, prevalence and proportions of bacterial species over time in both supra and subgingival samples were determined using the Quade test and adjusted for multiple comparisons. Results: Mean % of sites exhibiting plaque, gingival redness and BOP were significantly reduced during the course of the study. Significant decreases in mean counts were observed in both supra and subgingival samples. Mean total DNA probe counts (×105, ±SEM) at baseline, 3, 6 and 12 months were: 133±19, 95±25, 66±6, 41±6 (p<0.001) for supragingival samples and 105±22, 40±10, 19±4, 13±3 (p<0.001) for subgingival samples. Mean counts of 22 of 40 and 34 of 40 species tested were significantly reduced in the supra and subgingival samples respectively over the monitoring period. For example, mean counts of Porphyromonas gingivalis×105 at baseline, 3, 6 and 12 months in the subgingival plaque samples were 2.0±0.4, 0.5±0.2, 0.6±0.3, 0.3±0.1 (p<0.001); Bacteroides forsythus 2.0±0.6, 0.4±0.1, 0.4±0.2, 0.1±0.2 (p<0.001); Treponema denticola 3.4±1.1, 0.8±0.3, 0.4±0.2, 0.3±0.3 (p<0.01). Similar reductions were seen in supragingival plaque samples. While counts were markedly reduced by professional plaque removal, the proportion and prevalence of the 40 test species were marginally affected. Conclusions: Weekly professional supragingival plaque removal profoundly diminished counts of both supra- and subgingival species creating a microbial profile comparable to that observed in periodontal health. This profile was maintained at the final monitoring visit, 9 months after completion of therapy. [source]

Scanning Electron Microscope Analysis of Internal Adaptation of Materials Used for Pulp Protection under Composite Resin Restorations

JOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 2 2005
MARIA INEZ LEMOS PELIZ DDS
ABSTRACT Purpose:: The aim of this study was to evaluate the interfacial microgap with different materials used for pulp protection. The null hypothesis tested was that the combination of calcium hydroxide, resin-modified glass ionomer, and dentin adhesive used as pulp protection in composite restorations would not result in a greater axial gap than that obtained with hybridization only. Materials and Methods: Standardized Class V preparations were performed in buccal and lingual surfaces of 60 caries-free, extracted human third molars. The prepared teeth were randomly assessed in six groups: (1) Single Bond (SB) (3M ESPE, St. Paul, MN, USA); (2) Life (LF) (Kerr Co., Romulus, MI, USA) + SB; (3) LF + Vitrebond (VT) (3M ESPE) + SB; (4) VT + SB; (5) SB + VT; (6) SB + VT + SB. They were restored with microhybrid composite resin Filtek Z250 (3M ESPE), according to the manufacturer's instructions. However, to groups 5 and 6, the dentin bonding adhesive was applied prior to the resin-modified glass ionomer. The specimens were then thermo-cycled, cross-sectioned through the center of the restoration, fixed, and processed for scanning electron microscopy. The specimens were mounted on stubs and sputter coated. The internal adaptation of the materials to the axial wall was analyzed under SEM with × 1,000 magnification. Results: The data obtained were analyzed with nonparametric tests (Kruskal-Wallis, p V .05). The null hypothesis was rejected. Calcium hydroxide and resin-modified glass ionomer applied alone or in conjunction with each other (p < .001) resulted in statistically wider microgaps than occurred when the dentin was only hybridized prior to the restoration. [source]

An updated clinical and epidemiological profile of the adenomatoid odontogenic tumour: a collaborative retrospective study

JOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 7 2007
Hans Peter Philipsen
Background:, Adenomatoid odontogenic tumour (AOT) is a benign odontogenic jaw lesion. The aim of this study was to update the biological profile of AOT. Material and methods:, Cases published in the literature and cases in files of co-authors were included. Results:, 550 new cases were retrieved, and of a total of 1082 cases analysed, 87.2% were found in the second and third decades. The M:F ratio was 1:1.9. 70.8% were of the follicular variant (extrafollicular: 26.9%, peripheral: 2.3%). 64.3% occurred in the maxilla. 60% of follicular AOTs were associated with unerupted canines. Nineteen cases of AOT (2.8%, M:F ratio was 1:1.4) were associated with embedded third molars. Twenty-two peripheral AOTs (2.3%, M:F ratio was 1:5.3) were recorded. The relative frequency (RF) of AOT ranged between 0.6% and 38.5%, revealing a considerably wider AOT/RF range than hitherto reported (2.2,7.1%). Conclusions:, This updated review based on the largest number of AOT cases ever presented, confirms the distinctive, although not pathognomonic clinicopathological profile of the AOT, its worldwide occurrence, and its consistently benign behaviour. [source]