Randomized clinical trial of four adhesion strategies: A 42 month study.

CONTEXT: The adhesives clinical effectiveness has been extensively reported for noncarious cervical lesions (NCCLs). However, there is a lack of information about the adhesive systems strategies and their effect on NCCL restoration longevity. AIMS: This study aims to evaluate a 42-month performance of four dentin adhesive systems used for the restorative treatment of NCCLs. SETTINGS AND DESIGN: NCCLs were randomly divided into four groups: (1) Scotchbond multi-purpose (MP); 2: Single bond plus (SB); 3: Scotchbond SE (SE); and 4: Easy bond (EB). SUBJECTS AND METHODS: NCCLs (125) were randomly distributed: (1) MP; (2) SB; (3) SE; and (4) EB and were restored with a nanofilled resin-composite, evaluated along 18-36-42 months. STATISTICAL ANALYSIS USED: Kruskal-Wallis test: Comparison among the adhesive systems in each period. Friedman analysis: Comparison along the periods. Kaplan-Meier: Survival analysis. RESULTS: Baseline and 42-month retention (RET) rates (%) were 100/100 for MP; 100/94.74 for SB; 100/87.5 for SE; and 100/100 for EB. The cumulative failure percentage was 9.52% for MP, 9.52% SB, 15.8% SE, and 10% EB. Restorations survival was not dependent on the used adhesive type. Marginal adaptation (MA) was similar to each group, but EB presented noticeable marginal deterioration. Wear was noticed in the 3-step etch-and-rinse (MP) restorations evaluated after 42 months. For the EB, baseline and 18-month wear evaluation were statistically similar. After 36 and 42 months, wear was also similar for EB. CONCLUSIONS: Adhesive systems showed similar performance within most important adhesive bonding efficiency achievement parameters: RET, MA, interfacial staining, recurrent caries, and postoperative sensitivity evaluated during 42 months.

Stress and its role in the dentin hypersensitivity in rats.

INTRODUCTION: The perception of pain varies individually. Chronic stress leads to analgesia. The use of animal chronic mild stress model to mimic human condition was previously developed and now applied in the evaluation of pain perception in rats with dentin hypersensitivity (DH). AIMS: Using DH model induced by dentin erosion (DE) mediated by acidic solution, the present study aimed the evaluation of the interaction of chronic stress and pain induced by DH in rats with DE. METHODS: DH was induced by ad libitum 30-day intake of acidic solution. Stress was induced by the New York subway model. Body weight was weekly taken, during treatment. Groups WO (water, no stress), WS (water and stress), EO (acidic solution, no stress) and ES (acidic solution, stress) were submitted to treatments. RESULTS: After 30 days, all groups were submitted to DH test assessed by cold water stimuli in the labial surface of molars, for 5s, and the rats responses were scored as grades 0, 0.5, 1, 2, or 3. After euthanasia, blood was taken to obtain the levels of corticosterone, stomachs were observed in fresh preparations, kidneys and livers were submitted to histological evaluation. Open field model supported stress evaluation, as did corticosterone analysis. Stressed animals showed significant increase in pain perception and a decrease in locomotion frequency, tending to be more frequent in the periphery of the arena, corroborating stressed behavior and the need of protection as a pain relief. Corticosterone levels were increased in the stressed rats with dentin erosion and also corroborate present findings. Finally, reduction in weight gain was impaired in stressed group with dentin erosion. CONCLUSION: The animal model enabled the evaluation of how chronic mild stress interfered in DH pain perception.

Effect of chlorhexidine on the 18-month clinical performance of two adhesives.

PURPOSE: This study tested the hypothesis that 2% chlorhexidine (CHX) does not affect the 18-month clinical performance of two dentin adhesives, XP Bond (XPB) and XENO V (XEN). MATERIALS AND METHODS: A total of 120 noncarious cervical lesions (NCCL) were selected and assigned to 4 groups: (1) XPB; (2) CHX prior to the application of XPB; (3) XEN; (4) CHX prior to the application of XEN. A hybrid composite resin, Esthet•X, was used for all restorations. Restorations were evaluated blindly at 6 and 18 months by two evaluators using the University of North Carolina (UNC)-modified USPHS criteria. Statistical analyses included the Mann Whitney and McNemar nonparametric tests (p < 0.05). RESULTS: At 6 months, 91 (75.2%) restorations were evaluated, while 92 (76.7%) restorations were evaluated at 18 months. The 6-month/18-month overall retention rates (%) were 100/100 for XPB, 96.0/95.0 for CHX+XPB, 100/91.3 for XEN, and 100/95.8 for CHX+XEN with no statistical difference between any pair of groups at each recall. Sensitivity to air improved significantly for groups XPB, XEN, and CHX+XEN from pre-operative conditions to 1 week after insertion, to 6 and to 18 months after inserting. For group CHX+XPB, there was a statistically significant difference only between pre-operative conditions and 1 week after insertion. Marginal adaptation deteriorated for all groups, but no statistically significant differences were found. All other criteria remained statistically similar. CONCLUSION: The application of CHX prior to the dentin adhesive did not influence the 6-month/18-month clinical performance of the two adhesives.

Estudo in vitro da infiltração marginal em restaurações de resina composta aplicadas sobre superfícies dentinárias tratadas com proteína BMP associada ao laser de Nd: YAG / In vitro study of microleakage composite restoration in dentin surface treated with bone morphogenetic protein associated with Nd: YAG laser

Introdução - A proteína BMP tem sido encontrada nos processos de reparação óssea após fraturas, agindo como indutora de neoformação óssea. O objetivo deste estudo foi de avaliar a infiltração marginal em restaurações de resina composta aplicadas sobre dentina tratada com BMP associada à aplicação de irradiação com laser de Nd:YAG. Material e Método: Cinquenta e dois dentes bovinos foram divididos em três grupos. Todos os dentes receberam preparo de Classe V, padronizados em largura e profundidade e a restauração com resina composta também seguiu o mesmo protocolo para todos os dentes. O Grupo I foi o controle, onde os procedimentos foram realizados de forma convencional. No Grupo II a dentina recebeu tratamento com BMP associada a hidroxiapatita + colágeno seguida de irradiação com laser de Nd:YAG, técnica adesiva e restauração com RC. No Grupo III foi aplicada BMP (+hidroxiapatita +colágeno) + irradiação com laser de Nd:YAG + técnica adesiva + nova irradiação + restauração com RC. Após restaurações, as amostras foram termocicladas e submetidas à teste de microinfiltração. Resultados - Após a avaliação de três examinadores, foi realizada análise do teste exato de Fisher. A associação da irradiação com laser de Nd:YAG antes e após a aplicação da proteína BMP, mostrou resultados melhores que o grupo controle. Conclusão - A associação de irradiação com laser de Nd:YAG e proteína de BMP promoveu menor microinfiltração nos preparos de Classe V restaurados com resina composta