In vitro and In vivo Evaluationof Different Gingival Retraction Cords

Modern impression techniques used in restorative dentistry require displacementof gingival tissue to expose the subgingival finish lines on the tooth preparation. Many different medications are used on gingival retraction cords in order to minimize hemorrhage from the gingival sulcus during impression making. A common method of accomplishing gingival displacement is by packing cord into the gingival crevice. This is especially critical when using hydrophobic impression materials such as polyvinyl siloxanes. The purpose of this study was to determine whether any of the commonly used gingival retraction medications could inhibit the polymerization of polyvinyl siloxane impression materials when they are in direct contact with the setting material and to evaluate the clinical performance of retraction cords. Many gingival retraction cords in various shapes, sizes and medications are available on the market. The literature is replete with reports on the effects of medicated and non-medicated cords on impression and gingival tissue. In this study, the number of the criteria of evaluation was increased and both in vitro and in vivo studies were conducted together by three prosthodontists

Intraoral Repair of Metal Ceramic Restorations Following Preparation of the Endodontic Access Cavity (Case Reports)

The Manufacture of dental crowns and bridgework of porcelain fused to metal, a technique that results in highly functional and esthetic restorations, has been widely used for about 45 years. Bonded porcelain is exceptionally strong. However, the reasons for porcelain fracture may be multifactorial, and include where the bridge or crown substructure has been weakened by excessive occlusal adjustment or by the introduction of an endodontic access cavitiy. An esthetic and functional repair, wherever possible, has many advantages over time-consuming and expensive remakes of crowns and/or bridges. This report is a presentation of a simple method for both the dentist and the patient to repair a tooth with root canal treatment. In cases where the fracture is due to an endodontic access cavity, intraoral repair was performed using various porcelain repairing kits. The patients were recalled for follow up on a 3-month basis after treatment. This technique can be considered as a treatment of choice regarding the successful results

Pilot study of unidirectional E-glass fibre-reinforced composite resin splints: up to 4.5-year clinical follow-up

OBJECTIVES: This prospective clinical pilot study evaluated the performance of fibre-reinforced-composite resin (FRC) splints on mandibular anterior teeth. METHODS: Between June-2003 and January-2008, 19 patients (7 females, 12 males, 45-72 years old) from a group of consecutive patients who completed periodontal therapy received E-glass FRC splints (everStick Perio, StickTech) in combination with two types of flowable and restorative resin-composites (Filtek Flow, Filtek Supreme, n=11; Tetric Flow, Tetric-Ceram, n=8). Only patients with vital teeth, presenting mobility of grade 3, having at least one canine with no mobility on both sides of the dental arch were assigned for a splint therapy. The patients were recalled for periodical follow-up controls first at 6 months and thereafter annually. The evaluation protocol involved technical failures [chipping, debonding or fracture (tooth/restoration)] and biological failures (caries)]. Periodontal pocket depth (PPD) and clinical attachment level (CAL) were measured 6 months after splinting and annually. Six sites were measured for each natural tooth at the mesiobuccal, buccal, distobuccal, distolingual, lingual and mesiolingual sites. RESULTS: All splints were applied from canine to canine in the mandible. In total, 5 recalls were performed and no drop-out was experienced. One partial debonding of the FRC splint with Tetric Flow/Tetric-Ceram combination was observed after 40 months. No caries was found around any of the splints and no teeth had to be extracted until the final follow up. The splinted teeth were found to be vital in the vitality tests. Overall survival rate was 94.8% (Kaplan-Meier). The survival rate was not significantly affected by the composite type (Filtek-Flow/Filtek Supreme: 100%, Tetric Flow/Tetric Ceram: 96% (p=0.92) [Kaplan-Meier, Log Rank (Mantel-Cox) (CI=95%)]. Hazard ratio for Tetric Flow/Tetric Ceram group was 0.05 (95% CI) and for Filtek Flow/Filtek Supreme group 0.00 (95% CI). Whilst overall PPD measurements of the dentition ranged between 6 and 12 mm, the CAL measurements ranged between 4.9 and 10mm at baseline. The mean PPD for the splinted teeth decreased from 8.9±1.8 mm to 5.2±1.2 mm, and CAL decreased from 7.2±1.6 mm to 4.6±1 mm at the end point. CONCLUSION: Direct tooth splinting with E-glass FRC material performed successfully up to 4.5 years. Periodontal status of the splinted teeth showed decreased PPD and CAL

Fracture strength of fiber-reinforced surface-retained anterior cantilever restorations

PubMed ID: 18548961Purpose: This study compared the fracture strength of direct anterior cantilever fiber-reinforced composite (FRC) fixed partial dentures (FPD) reinforced with 3 types of E-glass fibers preimpregnated with either urethane tetramethacrylate, bisphenol glycidylmethacrylate/polymethyl methacrylate, or bisphenol glycidylmethacrylate monomers and 1 ultrahigh molecular weight polyethylene fiber. Failure types were also evaluated. Materials and Methods: A total of 40 caries-free, human maxillary central incisors (n = 10 per group) received surface-retained direct cantilever restoration (1 pontic) after etching and application of bonding agent. Four FRC materials were used (FRC1 = EverStick; FRC2 = BR-100; FRC3 = Interling; FRC4 = Ribbond), and pontics were built up using 1 particulate filler composite (Clearfil Photo Posterior). After the fracture test, failure types were analyzed. Results: No significant difference was found between the 4 FRC types veneered with particulate filler composite (893 ± 459 N to 1326 ± 391 N) (P = .1278). Complete pontic fracture at the connector area was most prominent for FRC4 (90%), followed by FRC3 (70%). Only FRC2 (10%) showed some fiber fractures, with half of the fiber remaining attached on the enamel surface of the abutment. Conclusion: The fracture strengths of cantilever FPDs made of 4 FRC materials with different monomer matrices and architectures, veneered with particulate filler composite, did not show significant differences. However, failure behavior varied between groups

Effects of non-silanized and silanized glass particles on the physical properties on denture base materials

23rd Symposium and Annual Meeting of International Society for Ceramics in Medicine, ISCM 2011 -- 6 November 2011 through 9 November 2011 -- Istanbul -- 87411The purpose of this study was to evaluate the effects of silanization of the glass on denture base materials and to evaluate different types of glasses. A total of 136 Poly(methyl methacrylate) (PMMA) (Palapress - Heraeus Kulzer) blocks were prepared in dimensions of 65mm × 10mm × 3mm. PMMA blocks were modified by different ratios of non-silanized and silanized Bioactive Glass Granules (BAG) (Vivoxid) and Inert Glass Granules (IG) (Vivoxid). The blocks were polished under water cooling and divided into 17 groups. (Group 1) No glass (control), (Group 2-5) 3-6-9-12% non-silanized BAG, (Group 6-9) 3-6-9-12% silanized BAG, (Group 10-13) 3-6-9-12% non-silanized IG, (Group 14-17) 3-6-9-12% silanized IG. The specimens were stored in distilled water and weighed (Mettler, Toledo) in days of 1, 2, 3, 7, 14, 21, 30, 45, 60. After water sorption test, the specimens were dried under 80°C and weighed in days of 0, 1, 2, 3, 5, 7, 9 for calculating the solubility values. Statistical analysis was performed using analysis of variance (ANOVA) followed by post-hoc comparisons (Dunnett T3, p<0.05). Water sorption and solubility values were significantly affected by the type and silanizaion of the glass (p<0.05). The highest water sorption value was observed in 12% silanized IG group (1,83±0,04%), whereas the lowest sorption values were recorded with 12% non-silanized BAG group (1,21±0,07%). Contrarily, The highest solubility value was observed in 12% non-silanized BAG group (0,98±0,03%), whereas the lowest solubility values were recorded with 12% non-silanized BAG group (0,34±0,03%). Water sorption and solubility values were affected by the type and silanization of the glass. Silanization improved the physical properties of the glass as well as the properties of the denture base material. © (2012) Trans Tech Publications