Evaluation of the agreement by examiners according to classifications of third molars

Objectives. This study recorded and evaluated the intra-and inter-group agreement degree by different examiners for the classification of lower third molars according to both the Winter's and Pell & Gregory's systems. Study Design. An observational and cross-sectional study was realized with forty lower third molars analyzed from twenty digital panoramic radiographs. Four examiner groups (undergraduates, maxillofacial surgeons, oral radiologists and clinical dentists) from Aracaju, Sergipe, Brazil, classified them in relation to angulation, class and position. The variance test (ANOVA) was applied in the examiner findings with significance level of p<0.05 and confidence intervals of 95%. Results. Intra- and inter-group agreement was observed in Winter's classification system among all examiners. Pell & Gregory's classification system showed an average intra-group agreement and a statistical significant difference to position variable in inter-group analysis with greater disagreement to the clinical dentists group (p<0.05). Conclusions. High reproducibility was associated to Winter's classification, whereas the system proposed by Pell & Gregory did not demonstrate appropriate levels of reliability.

Immunohistochemical Analysis of Human Homologue of Drosophila Patched (PTCH) in Dental Follicles of Impacted Third Molars

This study investigated the immunodetection of PTCH in epithelial components of dental follicles associated with impacted third molars without radiographic signs of pathosis. One hundred and five specimens of dental follicles associated with impacted third molars with incomplete rhizogenesis (between Nolla's stage 6 and 9) were surgically removed from 56 patients. Epithelial cell proliferation was determined by using immunohistochemical labeling. Statistical analysis was performed using Fisher exact test and a level of significance of 5%. Of the 105 dental follicles collected, 3 were PTCH-positive. The specimens with squamous metaplasia and epithelial hyperplasia had higher rates of positivity for PTCH, as well as those with active remnants of odontogenic epithelium. This study suggests that the odontogenic cells of the dental follicle might be proliferating during the rhizogenesis, while the squamous metaplasia and hyperplasia of the epithelial lining and proliferative odontogenic epithelial rests show the differentiation potential of dental follicles.

Mineralization of mandibular third molars can estimate chronological age-Brazilian indices

Forensic age estimation is an important element of anthropological research, as it produces one of the primary sources of data that researchers use to establish the identity of a person living or the identity of unknown bodily remains. The aim of this study was to determine if the chronology of third molar mineralization could be an accurate indicator of estimated age in a sample Brazilian population. If so, mineralization could determine the probability of an individual being 18 years or older. The study evaluated 407 panoramic radiographs of males and females from the past 5 years in order to assess the mineralization status of the mandibular third molars. The evaluation was carried out using an adaptation of Demirjian's system. The results indicated a strong correlation between chronological age and the mineralization of the mandibular third molars. The results indicated that modern Brazilian generation tends to demonstrate an earlier mandibular third molar mineralization than older Brazilian generation and people of other nationalities. Males reached developmental stages slightly earlier than females, but statistically significant differences between the sex were not found. The probability that an individual with third molar mineralization stage H had reached an age of 18 years or older was 96.8-98.6% for males and females, respectively. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

Assessment of Preemptive Analgesia Efficacy in Surgical Extraction of Third Molars

Background and objectives: Literature on preemptive analgesia is controversial. Reliability of results and difficult reproducibility of research contribute for non-elucidation of the subject. The aim of this study is to test the efficacy of oral ketoprofen (150 mg) preemptively administrated two days before third molar surgery, compared with postoperative administration in the same patient. Methods: Thirteen patients underwent surgical removal of bilateral third molar in two separate procedures. In a random and double blind procedure, oral ketoprofen 150 mg was administered every 12 hours two days before surgery and, after the procedure, the same drug was administered for three days. On the other side, a control (placebo) was used orally every 12 hours two days before surgery and, after the procedure, ketoprofen 150 mg was administered every 12 hours for three days. Postoperative pain was assessed by visual analogue scale, nominal scale, and amount of rescue analgesics consumed. Results: There was no statistically significant difference in postoperative pain between the preemptive treatment and control. Conclusion: In this experimental model, preemptive analgesia was not effective in reducing postoperative pain in surgical extraction of third molar compared with the postoperative administration of the same drug.

Sublingual ketorolac and sublingual piroxicam are equally effective for postoperative pain, trismus, and swelling management in lower third molar removal

Objective. Lower third molar removal provides a clinical model for studying analgesic drugs. The present study's aim was to compare the clinical efficacy of sublingual ketorolac and sublingual piroxicam in managing pain, trismus and swelling after lower third molar extraction in adult volunteers. Study Design. In this double-blinded, randomized, crossover investigation, 47 volunteers received for 4 days ketorolac sublingually (10 mg 4 times daily) and piroxicam sublingually (20 mg once daily) during 2 separate appointments after lower third molar extraction of symmetrically positioned lower third molars. A surgeon evaluated objective parameters (surgery duration, mouth opening, rescue analgesic medication, and facial swelling) and volunteers documented subjective parameters (postoperative pain and global evaluation), comparing postoperative results for a total of 7 days after surgery. The means of the objective and subjective parameters were compared for statistical significance (P < .05). Results. Volunteers reported low pain scores during the postoperative period when treated with either sublingual ketorolac or piroxicam. Also, volunteers ingested similar amounts of analgesic rescue medication (paracetamol) when they received either drug sublingually (P > .05). Additionally, values for mouth openings measured just before surgery and immediately after suture removal 7 days later were similar among volunteers (P > .05), and the type of nonsteroidal antiinflammatory drug (NSAID) used in this study showed no significant differences between swellings on the second or seventh days after surgery (P > .05). Conclusions. Pain, trismus, and swelling after lower third molar extraction, independent of surgical difficulty, were successfully controlled by sublingual ketorolac (10 mg 4 times daily) or sublingual piroxicam (20 mg once daily), and no significant differences were observed between the NSAIDs evaluated. (Oral Surg Oral Med Oral Pathol Oral Radiol 2012;114:27-34)

Evaluation of an Experimental Gel Containing Euclea natalensis: An In Vitro Study

Objective. To evaluate the effect of an experimental gel containing Euclea natalensis extract on dentin permeability. Methods. Thirty-six dentin discs, 1-mm-thick. The discs were prepared from the coronal dentin of extracted human third molars that were divided into 3 groups (n = 10). The dentin discs in each group were treated with the groups following experimental materials: (FG): 1.23% fluoride gel, pH 4.1; (EG): Euclea natalensis extract gel, pH 4.1; (CG): control gel, pH 4.1. The gels were applied to the occlusal slide of the dentin under the following conditions: after 37% phosphoric acid and before 6% citric acid. The hydraulic conductance (HC) of each condition was determined four times using a fluid flow apparatus (Flodec). The data were analyzed using Two-way ANOVA and Tukey's test (P < 0.05). Results. The greatest mean reduction in HC was produced in group EG dentin discs (61.2%; P < 0.05). Even after acid challenge with 6% citric acid the great reduction occurred in group EG (66.0%; P < 0.05) than other groups (CG-77.1%, FG-90.8%). Conclusion. E. natalensis gel not only reduced dentin permeability, but also resisted posttreatment citric acid challenge without changing its permeability. Further research has to confirm this promising result in the clinical situation.

Effects of water flow on ablation rate and morphological changes in human enamel and dentin after Er:YAG laser irradiation

Purpose: To investigate the laboratory effect of Er:YAG laser on ablation rate and morphological changes in human enamel and dentin with varying water flow. Methods: 23 human third molars were sectioned in mesio-distal and buccal-lingual directions. The slabs were flattened and weighted on an analytical laboratory balance (control). A 4-mm(2) area was demarcated and the samples were randomly assigned into three groups according to water flow employed during the laser irradiation (1.0, 1.5, and 2.0 mL/minute). An Er:YAG laser was used to ablate enamel (80.22-J/cm(2), 300 mJ/4Hz) and dentin (96.26-J/cm(2), 250 mJ/4Hz). After irradiation, the samples were immersed in distilled water for 1 hour and then weighted again. The final mass was obtained and laser-irradiated substrate mass loss was calculated by the difference between the initial and final mass. Afterwards, specimens were prepared for SEM. Results: Data were submitted to ANOVA and Tukey's test (P< 0.05). It was observed that the 2.0 mL/minute resulted in a higher mass loss, 1.0 mL/minute showed a lower mass loss, and 1.5 mL/minute demonstrated intermediate results (P< 0.05). The increase of water flow promoted less melting areas and cracks. Furthermore, dentin was more ablated than enamel. It may be concluded that the water flow of Er:YAG laser and the substrates affected the ablation rate. Among the tested parameters, 2.0 mL/minute improved the ability of ablation in enamel and dentin, with less morphologic surface alteration. (Am J Dent 20 12;25:332-336).

Effectiveness of immediate bonding of etch-and-rinse adhesives to simplified ethanol-saturated dentin

This study examined the immediate bond strength of etch-and-rinse adhesives to demineralized dentin saturated with either water or absolute ethanol. The research hypothesis was that there would be no difference in bond strength to dentin between water or ethanol wet-bonding techniques. The medium dentin of 20 third molars was exposed (n = 5). The dentin surface was then acid-etched, left moist and randomly assigned to be saturated via either water wet-bonding (WBT) or absolute ethanol wet-bonding (EBT). The specimens were then treated with one of the following etch-and-rinse adhesive systems: a 3-step, water-based system (Adper Scotchbond Multipurpose, or SBMP) or a 2-step, ethanol/water-based system (Adper Single Bond 2, or SB). Resin composite build-ups were then incrementally constructed. After water storage for 24 h at 37 degrees C, the tensile strength of the specimens was tested in a universal testing machine (0.5 mm/min). Data were analyzed by two-way ANOVA and Tukey's test (alpha = 5%). The failure modes were verified using a stereomicroscope (40x). For both adhesives, no significant difference in bond strength was observed between WBT and EBT (p > 0.05). The highest bond strength was observed for SB, regardless of the bonding technique (p < 0.05). No significant interaction between adhesives and bonding techniques was noticed (p = 0.597). There was a predominance of adhesive failures for all tested groups. The EBT and WBT displayed similar immediate bond strength means for both adhesives. The SB adhesive exhibited higher means for all conditions tested. Further investigations are needed to evaluate long-term bonding to dentin mediated by commercial etch-and-rinse adhesives using the EBT approach.

Influence of Ozone Gas and Ozonated Water Application to Dentin and Bonded Interfaces on Resin-Dentin Bond Strength

Purpose: To assess the influence of ozone gas and ozonated water application to prepared cavity and bonded interfaces on the resin/dentin bond strength of two-step etch-and-rinse adhesive systems (Adper Single Bond 2 [SB2] and XP-Bond [XP]). Materials and Methods: Sixty extracted human third molars were sectioned perpendicularly to their long axes to expose flat occlusal dentin surfaces. In experiment 1, dentin was treated with ozone before the bonding procedure, while in experiment 2, ozone was applied to resin/dentin bonded interfaces. In experiment 1, dentin surfaces were treated either with ozone gas (2100 ppm), ozonated water (3.5 ppm), or distilled water for 120 s, and then bonded with SB2 or XP according to manufacturers' instructions. Hybrid composite buildups were incrementally constructed and the teeth were sectioned into resin-dentin sticks (0.8 mm(2)). In experiment 2, dentin surfaces were first bonded with SB2 or XP, composite buildups were constructed, and bonded sticks obtained. The sticks were treated with ozone as previously described. Bonded sticks were tested under tensile stress at 1 mm/min. Silver nitrate impregnation along the resin/dentin interfaces was also evaluated under SEM. Results: Two-way ANOVA (adhesive and ozone treatment) detected no significant effect for the cross-product interaction and the main factors in the two experiments (p > 0.05), which was confirmed by the photomicrographs. Conclusion: Ozone gas and ozonated water used before the bonding procedure or on resin/dentin bonded interfaces have no deleterious effects on the bond strengths and interfaces.

Nd:YAG Laser Irradiation of Etched/Unetched Dentin Through an Uncured Two-step Etch-and-Rinse Adhesive and its Effect on Microtensile Bond Strength

Purpose: To evaluate whether Nd:YAG laser irradiation of etched and unetched dentin through an uncured adhesive affected the microtensile bond strength (pTBS). Materials and Methods: Flat dentin surfaces were created in 19 extracted human third molars. Adper Single Bond (SB) adhesive was applied over etched (groups 1 to 3) or unetched dentin (groups 4 to 6). The dentin was then irradiated with a Nd:YAG laser through the uncured adhesive, using 0.75 or 1 W power settings, except for the control groups (groups 1 and 4). The adhesive was light cured and composite crowns were built up. After 24 h, the teeth were sectioned into beams, with cross-sectional areas of 0.49 mm(2), and were stressed under tension. Data were statistically analyzed using two-way ANOVA and Tukey's test (alpha = 5%). Dentin surfaces of fractured specimens and the interfaces of untested beams were observed under scanning electron microscopy (SEM). Results: Acid etching, laser irradiation, and their interaction significantly affected bonding (p < 0.05). Laser irradiation did not improve bonding of etched dentin to resin (p > 0.05). However, higher pTBS means were found on unetched lased dentin (groups 5 and 6), but only in comparison to group 4, where neither lasing nor etching was performed. Groups 4 to 6 showed the lowest pTBS means among all groups tested (p < 0.05). Laser irradiation did not change the characteristics of the hybrid layers created, while solidification globules were observed on lased dentin surfaces under SEM. Conclusion: Laser irradiation of dentin through the uncured adhesive did not significantly improve the pTBS in comparison to the suggested manufacturer's technique.

Argon and Nd:YAG Lasers for Caries Prevention in Enamel

Objective: The aim of this study was to investigate the effect of Nd:YAG and argon laser irradiations on enamel demineralization after two different models to induce artificial caries. Background data: It is believed that the use of the high-intensity laser on the dental structure can lead to a more acid-resistant surface. Materials and methods: Twenty-one extracted human third molars were sectioned into tooth quarters. The quarters were distributed in three groups: Group I (control), untreated; Group II, Nd:YAG laser (60 mJ, 15 pps, 47.77 J/cm(2), 30 sec); and Group III, argon laser (250mW, 12 J/cm(2), 48 sec). Tooth quarters from each group were subjected to two different demineralization models: cycle 1, a 14 day demineralization (pH 4.5; 6 h) and remineralization (pH 7.0; 18 h) solutions, 37 degrees C and cycle 2, 48 h in demineralization solution (pH 4.5). Samples were prepared in slices (60-100 mu m thick) to be evaluated under polarized light microscopy. Demineralization areas were measured (mm(2)) (n = 11). Data were analyzed by ANOVA and Tukey's test (p < 0.05). Results: Means followed by different letters are significantly different: 0.25 A (control, cycle 48 h); 0.18 AB (control, cycle 14 days); 0.17 AB (Nd:YAG, cycle 14 days); 0.14 BC (argon, cycle 48 h); 0.09 BC (Nd:YAG, cycle 48 h), and 0.06 C (argon, cycle 14 days). Conclusions: The argon laser was more effective for caries preventive treatment than Nd: YAG laser, showing a smaller demineralization area in enamel.

Degradation of resin-dentin bonds of etch-and-rinse adhesive system to primary and permanent teeth

The aim of this in vitro study was to compare the degradation of resin-dentin bonds of an etch-and-rinse adhesive system to primary and permanent teeth. Flat superficial coronal dentin surfaces from 5 primary second molars and 5 permanent third molars were etched with phosphoric acid and bonded with an adhesive system (Adper Single Bond 2, 3M ESPE). Blocks of resin composite (Z250, 3M ESPE) were built up and the teeth sectioned to produce bonded sticks with a 0.8 mm(2) cross-sectional area. The sticks of each tooth were randomly divided and assigned to be subjected to microtensile testing immediately (24 h) or after aging by water storage (6 months). Data were analyzed by two-way repeated measures ANOVA and Tukey post hoc test (alpha = 0.05). Failure mode was evaluated using a stereomicroscope (400x). Microtensile values significantly decreased after the 6 months aging, independent of the dentin substrate. In 24 h, the values obtained to primary dentin were lower compared with permanent dentin. This difference was not maintained after aging. Adhesive/mixed failure was predominant in all experimental groups. In conclusion, degradation of resin-dentin bonds of the etch-and-rinse adhesive system occurred after 6 months of water storage; however, the reduction in bond strength values was higher for permanent teeth.

Multiple Tooth Agenesis in Non-syndromic Patient: a rare case report

Dental agenesis is a term referred to the absence of one or more teeth. However, oligodontia is a severe type of tooth agenesis involving six or more congenitally missing teeth, excluding the third molars. Oligodontia has a low prevalence and is a very rare condition. The aim was to show this case report of a 13-year-old female patient who presented oligodontia with absence of eight permanent teeth and condylar atrophy on left side. The patient had no history of any syndrome or systemic disease according to the anamnesis. Is very important to know oligodontia features to perform a carefully treatment plan.

Six-month evaluation of a resin/dentin interface created by methacrylate and silorane-based materials

Objectives: This study aimed to compare the micro-tensile bond strength of methacrylate resin systems to a silorane-based restorative system on dentin after 24 hours and six months water storage. Material and Methods: The restorative systems Adper Single Bond 2/Filtek Z350 (ASB), Clearfil SE Bond/Z350 (CF), Adper SE Plus/Z350 (ASEP) and P90 Adhesive System/Filtek P90 (P90) were applied on flat dentin surfaces of 20 third molars (n=5). The restored teeth were sectioned perpendicularly to the bonding interface to obtain sticks (0.8 mm2) to be tested after 24 hours (24 h) and 6 months (6 m) of water storage, in a universal testing machine at 0.5 mm/min. The data was analyzed via two-way Analysis of Variance/Bonferroni post hoc tests at 5% global significance. Results: Overall outcomes did not indicate a statistical difference for the resin systems (p=0.26) nor time (p=0.62). No interaction between material × time was detected (p=0.28). Mean standard-deviation in MPa at 24 h and 6 m were: ASB 31.38 (4.53) and 30.06 (1.95), CF 34.26 (3.47) and 32.75 (4.18), ASEP 29.54 (4.14) and 33.47 (2.47), P90 30.27 (2.03) and 31.34 (2.19). Conclusions: The silorane-based system showed a similar performance to methacrylate-based materials on dentin. All systems were stable in terms of bond strength up to 6 month of water storage.

Prevalência de dentes supranumerários na região dos pré-molares e sua associação com a presença dos terceiros molares

O objetivo do presente estudo foi determinar a prevalência de supranumerários na região dos pré-molares nos estágios de dentadura decídua, mista e permanente, além de verificar sua associação com a presença de terceiros molares. Foram avaliadas radiografias panorâmicas de 1.976 pacientes matriculados no curso de Ortodontia Preventiva e Interceptiva da Profis (Sociedade de Promoção Social do Fissurado Lábio-Palatal), em Bauru-SP. As radiografias foram analisadas em negatoscópio, em ambiente escurecido, por um único examinador que determinou a presença de supranumerários na região dos pré-molares, bem como a presença de terceiros molares. A associação entre o aparecimento de supranumerários e a presença de terceiros molares foi verificada pelo Teste de McNemar. O Teste exato de Fisher foi aplicado para verificar o dimorfismo sexual. Constatou-se uma prevalência de 0,45% de supranumerários na região dos pré-molares na amostra estudada, sendo 11% na maxila e 89% na mandíbula, e não foi observado dimorfismo sexual em relação ao aparecimento dos supranumerários (p=0,32). Nas radiografias avaliadas, foi observado que os quatro terceiros molares estavam presentes sempre que verificada a presença dos supranumerários, detectando uma associação estatisticamente significante (p < 0,01) entre o aparecimento dos pré-molares supranumerários e a presença dos terceiros molares. Concluiu-se que a incidência de pré-molares supranumerários foi baixa na população estudada, e que existe associação entre o aparecimento destes supranumerários com a presença dos terceiros molares.