ABSTRACT
The aims of this study were to evaluate the effect of immediate and delayed resin cement application on the microtensile bond strength of indirect composite resin restorations and, to evaluate adhesive strategies (for regular resin cement or humidity parameters for self-adhesive resin cement). Forty-five enamel/dentin discs (0.5 mm height and 10 mm of diameter) obtained from bovine teeth were divided into nine groups (n = 5). For regular cement, the variation factors were cementation technique at three levels (immediate cementation, 5 or 30 min after adhesive system application); and type of adhesive system at two levels (three- or two-step). For self-adhesive cement, the dentin moisture was the source of variation at three levels (normal, dry, or wet cementation). The specimens were submitted to microtensile bond strength (µTBS) testing using a universal testing machine. Data were analyzed by ANOVA, Tukey's test, and linear regression. Regular cement and three-step etch-and-rinse adhesive system showed the highest values of bond strength (25.21 MPa-30 min of delay). Only for this condition, three-step adhesive showed higher bond strength than the two-step adhesive. Nevertheless, the linear regression showed that irrespective of the strategy, the use of the two-step approach when compared with three-step adhesive system decreased µTBS (p < 0.001). The failure analysis showed predominant adhesive failures for all tested groups. All groups had comparable values of bond strength to bovine dentin when the same materials were used, even in suboptimal clinical conditions.
Subject(s)
Cementation/methods , Composite Resins/chemistry , Dental Restoration, Permanent/methods , Resin Cements/chemistry , Animals , Cattle , Dental Restoration Failure , Dentin/drug effects , Materials Testing , Random Allocation , Reference Values , Reproducibility of Results , Surface Properties , Tensile Strength , Time FactorsABSTRACT
The aims of this study were to evaluate the effect of immediate and delayed resin cement application on the microtensile bond strength of indirect composite resin restorations and, to evaluate adhesive strategies (for regular resin cement or humidity parameters for self-adhesive resin cement). Forty-five enamel/dentin discs (0.5 mm height and 10 mm of diameter) obtained from bovine teeth were divided into nine groups (n = 5). For regular cement, the variation factors were cementation technique at three levels (immediate cementation, 5 or 30 min after adhesive system application); and type of adhesive system at two levels (three- or two-step). For self-adhesive cement, the dentin moisture was the source of variation at three levels (normal, dry, or wet cementation). The specimens were submitted to microtensile bond strength (μTBS) testing using a universal testing machine. Data were analyzed by ANOVA, Tukey’s test, and linear regression. Regular cement and three-step etch-and-rinse adhesive system showed the highest values of bond strength (25.21 MPa–30 min of delay). Only for this condition, three-step adhesive showed higher bond strength than the two-step adhesive. Nevertheless, the linear regression showed that irrespective of the strategy, the use of the two-step approach when compared with three-step adhesive system decreased μTBS (p < 0.001). The failure analysis showed predominant adhesive failures for all tested groups. All groups had comparable values of bond strength to bovine dentin when the same materials were used, even in suboptimal clinical conditions.
Subject(s)
Animals , Cattle , Cementation/methods , Composite Resins/chemistry , Dental Restoration, Permanent/methods , Resin Cements/chemistry , Dental Restoration Failure , Dentin/drug effects , Materials Testing , Random Allocation , Reference Values , Reproducibility of Results , Surface Properties , Tensile Strength , Time FactorsABSTRACT
Despite the documented excellent clinical performance of dental implants, concerns linger regarding the best way to protect the restored dentition in patients with bruxism. This is because of the risk of occlusal overload that is reported to cause biological and biomechanical failures in the implant-prosthesis system. To better distribute occlusal loads to the rigid components of the prosthesis and to the interface between bone and implant during parafunctional movements, several dentists prescribe acrylic resin occlusal splints for nocturnal use by patients considered at risk. However, it is unclear whether this recommendation is based on scientific evidence or expert clinical opinion. This report reflects our effort to employ the systematic review protocol to assess whether there is scientific evidence to recommend an occlusal splint in bruxers after implant therapy.
