Context:Early observations of enamel surfaces prepared by erbium lasers motivated clinicians to use laser as an alternative to chemical etching.Aims:Evaluate shear bond strength (SBS) values of different dental adhesives on Erbium:Yttrium Aluminum Garnet (Er:YAG) laser prepared enamel and to evaluate possible etching patterns correlations between dental adhesives and SBS values.Subjects and Methods:One hundred bovine incisors were randomly assigned to SBS tests on enamel (n = 15) and to enamel morphology analysis (n = 5) after Er:YAG laser preparation as follows: Group I – 37% phosphoric acid (PA)+ ExciTE®; Group II – ExciTE®; Group III – AdheSE® self-etching; Group IV – FuturaBond® no-rinse. NR; Group V – Xeno® V. Teeth were treated with the adhesive systems and subjected to thermal cycling. SBS were performed in a universal testing machine at 5 mm/min.Statistical Analysis Used:One-way ANOVA and post-hoc tests (P < 0.05). For the morphology evaluation, specimens were immersed in Ethylenediamine tetraacetic acid (EDTA) and the etching pattern analyzed under Scanning Electron Microscope (SEM).Results:Mean bond strengths were Group I – 47.17 ± 1.61 MPa (type I etching pattern); Group II – 32.56 ± 1.64 MPa, Group III – 29.10 ± 1.34 MPa, Group IV – 23.32 ± 1.53 MPa (type III etching pattern); Group V – 24.43 MPa ± 1.55 (type II etching pattern).Conclusions:Different adhesive systems yielded significantly different SBSs. Acid etching significantly increased the adhesion in laser treated enamel. No differences in SBS values were obtained between AdheSE® and ExciTE® without condition with PA. FuturaBond® NR and Xeno® V showed similar SBS, which was lower in comparison to the others adhesives. No correlation between enamel surface morphology and SBS values was observed, except when PA was used.

Ozone is an important disinfecting agent, however its influence on enamel adhesion has not yet been clarified.Objective:Evaluate the influence of ozone pretreatment on the shear strength of an etch-and-rinse and a self-etch system to enamel and analyze the respective failure modes.Material and Methods:Sixty sound bovine incisors were used. Specimens were randomly assigned to four experimental groups (n=15): Group G1 (Excite® with ozone) and group G3 (AdheSE® with ozone) were prepared with ozone gas from the HealOzone unit (Kavo®) for 20 s prior to adhesion, and groups G2 (Excite®) and G4 (AdheSE®) were used as control. Teeth were bisected and polished to simulate a smear layer just before the application of the adhesive systems. The adhesives were applied according to the manufacturer's instructions to a standardized 3 mm diameter surface, and a composite (Synergy D6, Coltene Whaledent) cylinder with 2 mm increments was build. Specimens were stored in 100% humidity for 24 h at 37º C and then subjected to a thermal cycling regimen of 500 cycles. Shear bond tests were performed with a Watanabe device in a universal testing machine at 5 mm/min. The failure mode was analyzed under scanning electron microscope. Means and standard deviation of shear bond strength (SBS) were calculated and difference between the groups was analyzed using ANOVA, Kolmogorov-Smirnov, Levene and Bonferroni. Chi-squared statistical tests were used to evaluate the failure modes. Results:Mean bond strength values and failure modes were as follows: G1- 26.85±6.18 MPa (33.3% of adhesive cohesive failure); G2 - 27.95±5.58 MPa (53.8% of adhesive failures between enamel and adhesive); G3 - 15.0±3.84 MPa (77.8% of adhesive failures between enamel and adhesive) and G4 - 13.1±3.68 MPa (36.4% of adhesive failures between enamel and adhesive).Conclusions:Shear bond strength values of both adhesives tested on enamel were not influenced by the previous application of ozone gas.

The two-step self-etch adhesive system showed the lowest nanoleakage deposition compared with the other adhesive systems evaluated, which seems to indicate a better behavior when a restoration is performed in dentin and possibly can lead to a durable adhesion along time.

Aim:The study aimed to analyze the morphology of the dentinresin interface yielded by two-step etch-and-rinse adhesive systems with different solvents and compositions. Materials and methods:A total of 32 dentine disks were prepared and randomly assigned to four groups of one-bottle etchand-rinse adhesive systems containing different solvents: group I, Adper Scotchbond-1XT™ (ethanol/water); group II, XP-Bond™ (tertiary butanol); group III, Prime and Bond NT ® (acetone); and group IV, One Coat bond ® (5% water). Adhesive systems were applied onto dentin disks, which were then thermal cycled, divided into two hemi-disks (n = 16), and prepared for field-emission scanning electron microscopy to examine the dentin-resin interdiffusion zone. Microphotographs were scanned and data were processed. Data were compared with analysis of variance multivariant test after Kolmogorov-Smirnov and Shapiro-Wilk tests using Statistic Package for the Social Sciences. Results:The adhesive layer thickness average found was group I: 45.9 ± 13.41 µm, group II: 20.6 ± 16.32 µm, group III: 17.7 ± 11.75 µm, and group IV: 50.7 ± 27.81 µm. Significant differences were found between groups I and IV and groups II and III (p < 0.000).Groups I (3.23 ± 0.53 µm) and II (3.13 ± 0.73 µm) yielded significantly thicker hybrid layers than groups III (2.53 ± 0.50 µm) and IV (1.84 ± 0.27 µm) (p < 0.003). Group III presented a less homogeneous hybrid layer, with some gaps. Tag length average was greater in groups II (111.0 ± 36.92 µm) and IV (128.9 ± 78.38 µm) than in groups I (61.5 ± 18.10 µm) and III (68.6 ± 15.84 µm) (p < 0.008). Conclusion:Adhesives systems with different solvents led to significant differences in the dentin-resin interface morphology. Solvents role in adhesives bond strength should be considered together with the other adhesive system components. Morphology of the Clinical significance:The adhesive containing tertiary butanol, in addition, seems to originate a good-quality hybrid layer and long, entangled tags and also appears to have greater ability to originate microtags, which may indicate higher bond strength.

r e v p o r t e s t o m a t o l m e d d e n t c i r m a x i l o f a c . 2 0 1 5;5 6(2):132-138 informação sobre o artigo Historial do artigo: Recebido a 27 de agosto de 2014 Aceite a 14 de abril de 2015 On-line a 27 de maio de 2015 Palavras-chave: Calcificação dentária Facetas dentárias Trauma dentário Dentes tratados endodonticamente r e s u m o A obliteração do canal radicular caracteriza-se por uma redução do volume pulpar e pelo aparecimento de uma cor amarelada na coroa dentária, geralmente consequência de uma situação traumática. A frequência e extensão da obliteração dependem da gravidade do traumatismo e do grau de formação da raiz. A ausência de resposta aos testes de sensibilidade, bem como o escurecimento da coroa dentária, habitual nestes casos, impõe que seja feito o diagnóstico diferencial com situaç ões de necrose pulpar. Um diagnóstico erradopode implicar opç ões terapêuticas mais invasivas e eventualmente desnecessárias. Através de um caso clínico de um dente com obliteração do canal radicular pós-traumática, os autores salientam a importância da história clínica e dos aspetos de fisiologia pulpar envolvidos na resposta a esta situação adversa, apresentando uma solução terapêutica conservadora, estável e de grande satisfação para a paciente, usando facetas Componeer ® .