Simplified edentulous treatment: A multicenter randomized controlled trial to evaluate the timing and clinical outcomes of the technique.

STATEMENT OF PROBLEM: The time and cost of conventional complete denture procedures have been questioned in favor of simplified and faster methods. Whether the simplified edentulous treatment (SET) method yields complete dentures with acceptable outcomes is unclear. PURPOSE: The purpose of this randomized clinical trial (RCT) was to evaluate the outcomes of 2 techniques in providing complete dentures: the conventional and the SET methods. MATERIAL AND METHODS: Three Italian academic institutions participated in this single-blind parallel RCT. In total, 64 participants were selected and agreed to join the study. They were allocated randomly to 1 of 2 treatment groups, the conventional and SET group: 32 participants per group, 50% women in each group. Treatment was provided by final year predoctoral dental students. The time required for the clinical and laboratory procedures, the number of clinical sessions, and the laboratory returns were recorded. The clinical quality of the dentures and participant satisfaction were evaluated using questionnaires. Differences between treatment group outcomes were analyzed with 2-tailed independent sample Student t tests for clinical and technical timing and clinical and technical steps and Mann-Whitney U tests for denture quality and participant satisfaction (α=.05). RESULTS: The clinical time required (-34%, P<.001), number of clinical sessions (-34%, P<.001), and laboratory returns (-46.5%, P<.001) were significantly lower for the SET than for the conventional method. The laboratory time required (-10.6%) was not significantly less with the SET method (P=.06). Participant satisfaction (P=.816) and prosthodontist ratings of denture quality (P=.539) were comparable between the groups. The participants appreciated the reduced number of clinical sessions with SET (P=.003). CONCLUSIONS: Simplified edentulous treatment may be considered a reliable method for providing complete dentures in a shorter timeframe while maintaining denture quality and patient satisfaction.

Effect of post-cure heating on the flexural strength of two indirect resin composites.

The aim of this study was to evaluate whether a post-cure heat-treatment may improve the flexural strength of two indirect resin-based composites. Tested factors were: material (Gradia Indirect, Gradia Forte), mass (opaqus dentin, dentin, enamel) and curing mode (light, light and heat). A three-point bending test appliance was developed according to ISO 4049/2000. Three-Way ANOVA and 2-Pameter Weibull cumulative distribution function were performed. Factors material and curing mode were significant (p < 0.001), while the mass type was not (p = 0.181). A post-cure heat treatment may be useful for enhancing the flexural strength of both materials.

Effect of storage time on the accuracy of casts made from different irreversible hydrocolloids.

AIM: Several new irreversible hydrocolloid formulations have recently become available with claims of an improved dimensional stability by the manufacturers. The aim of this study was to evaluate the accuracy of casts made from alginate impression materials poured immediately and after specific storage periods. METHODS AND MATERIALS: Five alginates were tested: CA 37 (Cavex); Jeltrate (Dentsply Caulk); Jeltrate Plus (Dentsply Latin America); Hydrogum 5 (Zhermack); and Alginoplast (Heraeus Kulzer). A master model was mounted on a special device and used to obtain the impressions. These impressions were stored at 23 degrees C and 100% relative humidity, then poured with gypsum immediately, and again after 24, 72 and 120 hours. The casts were measured and the data were analyzed by one way analysis of variance (ANOVA) and Tukey test at p<0.05. RESULTS: The dimensional stability of the alginate impressions was both material and time dependent (p<0.05). After 24 hours of storage, only Alginoplast and Hydrogum 5 comply with the master model (p>0.05). After 72 and 120 hours, only Hydrogum 5 was dimensionally stable (p>0.05). CONCLUSION: The dimensional stability of the alginate impressions is influenced by the selected material and the storage time. CLINICAL SIGNIFICANCE: Alginate impressions should generally be poured immediately. However, some new types of alginate may have the pouring delayed.

SEM evaluation of the cement layer thickness after luting two different posts.

PURPOSE: To verify with SEM the cement layer thickness and uniformity of resin-relined translucent fiber posts (anatomic posts) and standard translucent fiber posts. MATERIALS AND METHODS: On 20 extracted maxillary anterior teeth, the roots were endodontically treated and prepared for the insertion of a fiber post. Translucent fiber posts (DT) were luted with a dual-curing resin cement (Duo-Link) in 10 specimens (group 1) after the canal walls had been treated with the One-Step bonding system. In the other 10 specimens (group 2), experimental anatomic posts (Anatomic Post'n Core) were tested. To these posts, a layer of light-curing resin is added to allow for a pre-cementation relining of the post, aimed at improving its fit into the endodontic space. For luting, the same adhesive-resin cement combination of group 1 was used. All the roots were sectioned and prepared for SEM observations. At the 1-mm, 4.5-mm, and 8-mm level of each root, cement thickness was measured, and the presence of gaps or voids within the luting material or at its interfaces was evaluated. A statistical analysis was performed to test the significance of differences in the cement layer thickness around the two types of post and at different levels of the same type of post. RESULTS: In the presence of anatomic posts, the cement layer was significantly thinner and more uniform at the coronal and middle level of the root. In both groups, voids and bubbles were detected within the luting material, within the abutment material, and between fiber post and cement. Gaps were also visible between post and relining material. CONCLUSIONS: The resin cement thickness was significantly lower in the anatomic post group than in the control group (standardized posts), except at the apical third of the canal, where there was no statistically significant difference. A good adaptation of anatomic posts was evident in all of the specimens.