Abstract Objectives A single-blinded, randomized, parallel clinical trial evaluated the use of 37% carbamide peroxide (CP) on bleaching effectiveness and tooth sensitivity reported by patients undergoing in-office tooth bleaching, in comparison with the results of using 35% hydrogen peroxide. Material and Methods Forty patients were allocated to receive two sessions of in-office tooth bleaching using either 35% hydrogen peroxide (HP) or 37% CP. Each patient’s sensitivity level was evaluated during and up to 24 h after bleaching. The effectiveness of the bleaching procedures was evaluated with a spectrophotometer one week after each session and 30 days after the last session. The impact of tooth bleaching on the patients’ perceptions regarding smile changes, in addition to the bleaching procedures and their results, were also recorded. Absolute and relative sensitivity risks were calculated. Data on sensitivity level were analyzed using the Mann-Whitney or T-test, and data from the color evaluation were subjected to 2-way repeated measures ANOVA. Results The use of CP reduced the risk and level of tooth sensitivity to values close to zero, whereas the difference between the bleaching agents disappeared after 24 h. An increased bleaching effect was observed for HP, mainly due to an improved reduction of redness and yellowness. Participants perceived improved tooth bleaching for HP and reduced sensitivity for CP, but no differences regarding the comfort of the techniques were noted. Conclusions In our study, 37% CP resulted in reduced tooth sensitivity but decreased the tooth bleaching effectiveness. However, both bleaching agents resulted in high levels of patient satisfaction.

The aim of this study was to evaluate the effect of immediate and delayed photoactivation of self-adhesive resin cements (SARCs) on the retention of glass-fiber posts luted into root canals. Bovine incisors were endodontically treated, and post holes of 9 mm in depth were prepared. Fiber posts were luted using one of two SARCs, BisCem(r) (Bisco Inc., Schaumburg, USA) or RelyX Unicem clicker (3M ESPE, Saint Paul, USA), or a regular (etch-and-rinse) resin cement (AllCem; FGM, Joinvile, Brazil). Photoactivation was performed immediately, or at 5 or 10 min after cementation. Root/post specimens were transversely sectioned 7 days after luting into 1-mm-thick slices, which were submitted to push-out testing in a mechanical testing machine. Bond strength data were analyzed by two-way ANOVA and Student-Newman-Keuls' method (α = 0.05). Immediate photoactivation resulted in the highest bond strength for Unicem. BisCem(r) demonstrated higher bond strength values when photoactivated after a 10-min delay. Immediate photoactivation yielded the lowest bond strengths for AllCem, although no differences in bond strength were observed between photoactivation delayed by 5 and 10 min. In conclusion, the moment of resin cement photoactivation may affect the intraradicular retention of fiber posts, depending upon the resin cement used for luting.

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.

Se investigó la inmunodetección de PTCH en los componentes epiteliales de los folículos dentales asociados a terceros molares retenidos sin signos radiográficos y morfológicos de patología. Fueron quirúrgicamente extraídos de 56 pacientes 105 muestras de folículos dentales asociadas a terceros molares retenidos con rizogénesis incompleta (entre el estadio de Nolla 6 y 9). La proliferación de células epiteliales se deteminó mediante inmunohistoquímica. El análisis estadístico se realizó mediante la prueba exacta de Fisher. De los 105 folículos dentales recogidos, 3 fueron PTCH-positivos. Las muestras con metaplasia escamosa e hiperplasia epitelial tuvieron mayores tasas de positividad para PTCH, así como aquellos con los restos de proliferación del epitélio odontogénico. En conclusión, este estudio sugiere que las células odontogénicas del folículo dental podrían estar proliferando durante la rizogénesis, mientras que la metaplasia escamosa e hiperplasia del epitelio y de restos epiteliales odontogénicos en proliferación muestran el potencial de diferenciación de los folículos dentales.

The bifid mandibular condyle is an exceedingly rare anomaly, frequently diagnosed as an incidental finding in a panoramic radiograph. Its etiology and pathogenesis are unknown, though the most acceptable theory suggests that trauma is at the origin of the condition. This article reports a new case of bilateral bifid condyle in a 21-year-old female with history of trauma in childhood.

El proceso condilar bífido es una anomalía muy rara. Se diagnostica como un hallazgo accidental en una radiografía panorámica. Su etiología y patogenia son desconocidas, aunque la teoría más aceptada sugiere que el trauma está en el origen de esta condición. Este artículo presenta un nuevo caso de proceso condilar bífido bilateral en una mujer de 21 años de edad con antecedentes de trauma en la infancia.