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Biomedical subjects

F Mannocci

Publications and source records attributed to F Mannocci.

31 records · Page 2Linked to original sources

Stereomicroscopic and scanning electron microscopic study of roots obturated with vertically condensed gutta-percha, epoxy resin cement, and dentin bonding agent.

Root canal fillings performed with dentin bonding agent, gutta-percha, and epoxy resin sealer were observed by stereomicroscope. Fourteen palatal roots of extracted maxillary molars were used. Seven roots (group 1) were filled with gutta-percha, epoxy resin sealer, and dentin bonding agent. Seven (group 2) were filled with gutta-percha and epoxy resin sealer alone. The presence of these materials (gutta-percha, adhesive, cement, and a combination of these materials) and the number of voids present were evaluated in the apical, middle, and coronal thirds of the canals. In group 1, a combination of the three materials used was found to be the statistically most frequent case only in the apical third. No statistically significant difference was found between the overall number of voids present in the two groups. The resin-dentin-gutta-percha interface of roots from group 1 was observed by scanning electron microscopy: no statistically significant difference was found between apical and coronal sections regarding the presence of hybrid layer, penetration of resin into the dentinal tubules, or the presence of gaps in either the dentin-resin interface or the resin-gutta-percha interface.

Bismuth↗

Apical seal of roots obturated with laterally condensed gutta-percha, epoxy resin cement, and dentin bonding agent.

The apical seal of roots obturated with either of two kinds of dentin bonding agent, gutta-percha and epoxy-resin-based root canal sealer, was compared by a die leakage test with that of an epoxy resin root canal sealer and gutta-percha without a bonding agent. Thirty-two roots were prepared chemomechanically and divided into three experimental groups. Group 1 was filled with gutta-percha, epoxy-resin sealer, and All-Bond 2 Adhesive. Group 2 was filled with gutta-percha, epoxy-resin sealer, and Scotchbond Multi-Purpose Plus adhesive. Group 3 was filled with gutta-percha and epoxy resin sealer. The teeth were immersed in 2% methylene blue solution. Groups 1 and 2 leaked significantly less than group 3. The materials most frequently observed at the apex were in group 1 dental adhesive and in group 2 gutta-percha. The interface between dentin and the adhesive materials in groups 1 and 2 was examined by scanning electron microscope and showed a hybrid-like layer.

Dental Leakage↗

Short-term assessment of leakage of Class V composite restorations placed in vivo.

The purpose of this study was to investigate the effectiveness of two dentin bonding systems, one of which was also in combination with a self-curing resin, when applied in V-shaped circular cavities cut in anterior teeth crossing the cementum-enamel junction. Twenty-seven teeth scheduled for extraction for periodontal reasons were treated in vivo. The sample teeth were divided at random into three groups. Group 1 was treated with All Bond 2 (AB2) + Z-100 composite, group 2 with Scotchbond Multipurpose Plus (SMPP) + Z-100, and group 3 with AB2 in conjunction with Bisfil 2B as liner and Z-100. The in vivo restored teeth were extracted after 2-3 months of clinical service. They were then immersed in a dye solution for 24 h, sectioned, and scored for marginal leakage. Analysis of variance revealed no significant differences between the three groups both at cervical and incisal sites. The enamel sites were free from any leakage. Only two cervical sites of groups 1 and 2 and one of group 3 showed a score 1 for leakage. The results of the short-term clinical performance of the three systems were promising.

Analysis of Variance↗

Sealing ability of several restorative materials used for repair of lateral root perforations.

Amalgam, IRM, Vitremer, Bisfil, and Ana Norm Liner were evaluated for repair of experimentally induced lateral perforations. Eighty-five sound, mandibular, and maxillary molars, extracted for periodontal reasons, were selected for this study. The sample teeth were randomly divided in five groups with 15 specimens each. Ten teeth were used as control groups. After the perforations were filled with the above-mentioned materials, the teeth were immersed in a 2% methylene blue solution for 48 h, sectioned, and dye penetration was measured. The results indicated that Bisfil 2 B provided a significantly better seal than the other materials.

Coloring Agents↗

Effect of two etching times on the sealing ability of Clearfil Liner Bond 2 in Class V restorations.

PURPOSE: To investigate the sealing ability of the Clearfil Liner Bond 2 self-etching primer in Class V restorations placed under clinical and laboratory conditions. MATERIALS AND METHODS: Firstly, the influence of two etching times of the self-etching primer were tested in vitro. In 10 Class V cavities (Group 1), the self-etching primer was applied for 30 seconds on the enamel and dentin, while in another 10 Class V cavities (Group 2) the etching time was 60 seconds. Since the Group 2 samples showed the best in vitro sealing ability at both the enamel and cementum-dentin sites, the teeth of Group 3 (10 restorations) were restored as in Group 2 under clinical conditions, applying the self-etching primer for 60 seconds. The sample teeth were extracted after 65-90 days, and then processed for leakage. Two other groups of 10 samples each were prepared under laboratory conditions to investigate hybrid layer, resin tags and adhesive lateral branch formation. A flat buccal surface on each extracted tooth was prepared. Group 4 samples were conditioned for 30 seconds, and those of Group 5 for 60 seconds. RESULTS: In Group 1, 40% of the restorations showed leakage at the cementum-dentin site and 40% at the enamel site. Groups 2 and 3 showed statistically significant difference (less leakage) than Group 1. In Group 2 and 3 no leakage was found at the enamel site, and only a moderate leakage (10% and 20% of restorations, respectively) was found at the cementum-dentin site. The scanning electron microscopy observations of Group 4 samples showed a thin hybrid layer, with well-fitting and smooth resin tags and adhesive lateral branches only sporadically. Group 5 samples presented a thicker hybrid layer, rough and deep resin tags with many adhesive lateral branches. The etch enamel pattern was more uniform and rougher in Group 5 than in Group 4. The 60-second application time of the self-etching primer seems to be more reliable than a shorter conditioning time in day-to-day practice.

Acid Etching, Dental↗

Bond strengths of a porcelain material to different abutment substrates.

The study evaluated the bond strength values of a single-unit all-porcelain material luted with an adhesive-resin cement to different abutment substrates: amalgam, compomer, traditional glass ionomer cement, microhybrid resin composite, two resin composites for abutment build-up, gold, sandblasted gold, dentin and enamel. Syntac enamel-dentin bonding system, in combination with IPS-Empress porcelain material, was used. After thermal cycling, the samples were inserted into a Bencor jig device and sheared in a Controls testing machine. The statistical analysis of the differences between the bond strength values obtained was performed by ANOVA and the Student-Newman-Keuls multiple-comparison test. The type of failure at the interface was evaluated using scanning electron microscopy. The type of failure, such as adhesive, cohesive and adhesive-cohesive, was correlated with bond strength values. Enamel, dentin and the two resin composites for crown build-up showed the highest bond strength values, while amalgam and gold samples showed the lowest.

Adhesiveness↗