Microleakage of posterior composite restorations lined with self-adhesive resin cements.

PURPOSE: This study determined the microleakage of Class II composite restorations lined with self-adhesive resin-cements as bonding agents. METHODS: Forty-five caries-free extracted molars were sterilized, mounted in acrylic bases and divided into five equal groups according to the adhesive used: RXU (RelyX-Unicem, self-adhesive resin-cement, 3M ESPE), BRZ (Breeze, self-adhesive resin-cement, Pentron Clinical Technologies), MON (Monocem, self-adhesive resin-cement, Shofu), PAN (Panavia-F-2.0, resin-cement with self-etch primer, Kuraray) and SBMP (Scotchbond Multi-Purpose, total-etch three-step adhesive, 3M ESPE). Class II MOD cavities were prepared with gingival floors located on dentin at one side and on enamel on the other. The bonding agent SBMP, used according to the manufacturer's directions, or a thin layer of resin cement, was applied on all cavity walls and cavosurface margins. Filtek Z250 (3M ESPE) was used to restore cavities in all groups. The specimens were subjected to 1,000 thermocycles between 5 degrees C and 55 degrees C. All tooth surfaces were sealed with nail-varnish to within 1 mm from the restoration margins. The specimens were immersed in 2% fuchsine red solution for 24 hours at 37 degrees C. The teeth were then sectioned mesiodistally and dye penetration was assessed according to a five-point scale. Data were statistically analyzed with the Chi-square test (p < 0.05). RESULTS: Microleakage scores revealed that, on enamel margins, the SBMP group had significantly less microleakage than the RXU and BRZ groups, which, in turn, had significantly less microleakage than the MON and PAN groups; whereas on dentin margins, the RXU and BRZ groups had significantly less microleakage than the SBMP, MON and PAN groups. CONCLUSIONS: This in-vitro study showed that, when two self-adhesive resin-cements (RXU & BRZ) were used as liners in Class II composite restorations, they resulted in low microleakage scores as compared to the two other cements at both the enamel and dentin cavosurface margins.

A radiopaque implant template for partially edentulous patients.

This article describes a technique to fabricate a radiographic template using a vacuum-formed template with radiopaque putty impression material. This allows the position and contour of the proposed restoration to be seen with computerized tomography (CT). After planning, the radiographic template can be modified to be used as a surgical guide.

Screw- versus cement-retained implant prostheses: a systematic review of prosthodontic maintenance and complications.

PURPOSE: This systematic review aimed to identify different prosthodontic outcomes between screw- and cement-retained implant prostheses. MATERIALS AND METHODS: The relevant articles were retrieved from the following electronic databases: MEDLINE, EMBASE, PubMed (using medical subject headings), and the Cochrane Central Register of Controlled Trials (CENTRAL). The search was performed up to December 31, 2013, and was restricted to studies on human subjects reported in English. A further search was conducted through the reference lists of the articles found as well as from early online articles. Reviewed studies were those on fixed implant prostheses using different retention mechanisms such as screws or cement. Information on types of screws and mechanisms of preloading, as well as different luting cements, was collected in correlation with prosthodontic maintenance/complication issues seen in the clinical studies. RESULTS: Sixty-two papers met the review criteria. There were only six randomized controlled trials and none of them included an equivalent number of screw- and cement-retained single implant crowns for comparison. Studies used different types of screws and only a few reported the preloading procedure for the prosthetic screws. Other studies involving cement-retained implant prostheses used a range of dental cements; however, some did not specify the type used. Studies reported various prosthodontic maintenance/complication issues such as screw loosening, porcelain fracture, loss of retention, and esthetic concerns. Five studies did not report any prosthodontic maintenance issues during their observation periods. More recent studies also did not report any incidence of screw loosening. Only two studies stated the standardized criteria for reporting their prosthodontic maintenance/ complication issues. CONCLUSIONS: With inadequate information and various study designs, it was difficult to compare the prosthodontic outcomes between screw and cement-retained fixed implant prostheses. Both retention mechanisms showed prosthodontic maintenance/complication issues that must be considered and this review showed that the introduction of newer implant components may assist in minimizing these issues. It is also recommended that standardized criteria be used when reporting prosthodontic maintenance/complication issues to allow better comparison of data.

Dental fusion: a case report of esthetic conservative management.

The management techniques reported for dental fusion are usually complex, invasive, and irreversible. This case report describes a novel, simple technique to manage double teeth using resin restorations. The promising results obtained will encourage dental practitioners to consider this conservative approach before more complex treatment alternatives.

Retention of overdenture posts cemented with self-adhesive resin cements.

This study investigated the effects of two self-adhesive resin cements on the retention of overdenture anchor posts after 30 days of aging in water. Forty caries-free human canines were randomly assigned to four test groups. Uni-Anchor posts were cemented to specimens in groups A and B with Breeze and Maxcem self-adhesive resin cements, respectively. In groups C and D, Fuji glass-ionomer cement and Fleck's zinc phosphate cement were used, respectively. Specimens were stored in distilled water at 37 degrees C for 30 days. Each specimen was loaded in tension in an Instron universal testing machine. The maximum force required to dislodge each post was recorded. Means and standard deviations (SDs) were calculated and data were statistically analyzed with analysis of variance (ANOVA). Means and SDs were 706.5 +/- 204.6 N for Breeze, 585.1 +/- 213.5 N for Maxcem, 449.2 +/- 181.1 N for Fuji, and 330.4 +/- 120.6 N for Fleck's. ANOVA revealed significant differences among the means (P < .0003). Adhesive failure was observed with all groups except group A, in which eight specimens underwent a cohesive fracture of the dentin. Breeze cement (group A) resulted in the highest retention force and most frequent cohesive failure and thus would be expected to clinically perform in a superior manner.