Fracture resistance of endodontically treated teeth restored with ceramic inlays and different base materials.

This study evaluated the fracture resistance of endodontically treated teeth restored with different base materials and mesioocclusal-distal (MOD) ceramic inlays. Fifty mandibular molars were assigned into five groups (n=10 per group). Group1 (control) comprised intact molar teeth without any treatment. Teeth in other groups were subjected to root canal treatment and restored with MOD ceramic inlays on different base materials. In Group 2, base material was zinc phosphate cement; Group 3's was glass ionomer cement; Group 4's was composite resin, and Group 5's was composite resin reinforced with fiber. Finally, a continuous occlusal load was applied until fracture occurred. Mean fracture resistance of Group 1 (3,027 N) was significantly higher than the other groups (890, 1,070, 1,670, 1,226 N respectively). Fracture resistance of Group 4 was statistically comparable with Group 5 and significantly higher than Groups 2 and 3 (p<0.05; Tukey's HSD). Use of different base materials under ceramic inlay restorations could affect the fracture resistance of endodontically treated teeth.

The fracture resistance of teeth restored with different adhesive dowels.

OBJECTIVE: Fiber-reinforced composite dowels are suggested to be a better alternative to metal dowels. This in vitro study evaluated the fracture resistance and fracture modes of teeth restored with nine different dowel systems. MATERIALS AND METHODS: Ninety mandibular pre-molar teeth were decoronated and nine homogenous groups were composed. Root canal and dowel canal preparations were made and nine different dowel systems were used to fabricate restorations. Core build-ups were made with a composite resin core material. Specimens were mounted in acrylic resin blocks and continuous compressive force was applied until fracture occurred. Fracture resistance and fracture mode data were collected. One-sample Kolmogorov-Smirnov and one-way ANOVA tests were performed for the fracture resistance data of the groups. RESULTS: There were no significant differences among the fracture resistances of the groups. All specimens of the pre-fabricated stainless steel dowel group fractured catastrophically. However, even in the worst-case, five specimens of the fiber-reinforced composite groups had favorable fracture modes. CONCLUSIONS: The teeth restored with fiber reinforced composite dowels were as resistant to fracture as teeth restored with stainless steel dowels. Fracture modes of teeth restored with fiber reinforced composite dowels were more advantageous than teeth restored with pre-fabricated stainless steel dowels.

Clinical and microbiological efficacy of three different treatment methods in the management of denture stomatitis.

OBJECTIVE: This study evaluated. the effect of mouthrinses and tissue conditioner on the clinical findings and microbial flora of 60 patients with Newton's type II denture stomatitis (N2DS) BACKGROUND: Denture stomatitis is a common problem in complete denture wearers. MATERIALS AND METHODS: Sixty patients with N2DS were included in this study and divided into three groups. Two groups of patients were instructed to rinse their mouth with the designated mouthrinses DioxiDent and Corsodyl twice daily for 1 min and to soak their dentures overnight in these solutions for 15 days. For the third group, tissue conditioner was placed in each of 20 patients' existing maxillary dentures. Patients were evaluated both clinically and microbiologically at baseline and after 15 days. Palatal swabs and smears were taken from each patient before and after treatment and these samples were examined mycologically. The difference between Candida colonisation before and after treatment and the differences between pre-treatment and post-treatment clinical findings were assessed. RESULTS: DioxiDent and Corsodyl showed an improvement in palatal inflammation and a decrease in Candida colonisation compared to Visco-gel. CONCLUSIONS: The effectiveness of topical chlorine dioxide and chlorhexidine gluconate in the management of N2DS was demonstrated.

A 1- to 12-year clinical evaluation of 106 endosseous implants supporting fixed and removable prostheses.

The purpose of this article is to report on the long-term clinical evaluation of patients treated with dental implants. A total of 106 implants were placed in 34 patients and restored with fixed partial dentures and overdentures. The 12-year cumulative implant survival and success rates were 95.2% and 90.2%, respectively. Probing depths around mandibular implants were significantly lower than those around maxillary implants (P < .05). The cumulative implant success rate in nonsmokers was 97.7%, but this dropped to 75.81% in smokers. Also, patients rehabilitated with implant-supported overdentures had more peri-implant tissue inflammation than patients with fixed prostheses.

Replacing an anterior metal-ceramic restoration with an all-ceramic resin-bonded fixed partial denture: a case report.

Since the first resin-bonded fixed partial denture was described, this adhesive technique for splinting mobile teeth has developed into a conservative method for replacing missing teeth. Heat-pressed all-ceramic materials have been introduced for the fabrication of 3-unit fixed partial dentures in the anterior and premolar region. This clinical report describes the replacement of a conventional partial coverage metal-ceramic resin-bonded fixed partial denture with an all-ceramic resin-bonded fixed partial denture in the anterior maxillary area.

Effect of dentin bonding and ferrule preparation on the fracture strength of crowned teeth restored with dowels and amalgam cores.

STATEMENT OF PROBLEM: It is necessary to obtain an adequate bond at the core/dentin junction where the majority of failures occur. The effect of recently developed dentin bonding agents on the fracture resistance of endodontically treated teeth at the amalgam core/dentin junction is unclear. PURPOSE: The purpose of this study was to evaluate the effects of 2 dentin bonding agents and a ferrule preparation on the fracture resistance of crowned mandibular premolars incorporating prefabricated dowel and silver amalgam cores. MATERIAL AND METHODS: Sixty extracted mandibular second premolars were divided into 6 groups of 10 each. The coronal portion of each tooth was removed at the cemento-enamel junction (CEJ) in the first 3 groups. In the other groups, teeth were sectioned 1 mm above the CEJ to create a ferrule. After root canal preparations, prefabricated dowels (ParaPost) were placed. The first group served as a control and was tested without application of bonding agents and without incorporation of a ferrule design. In the second and third groups, respectively, an autopolymerizing adhesive (Superbond D-Liner) and a dual-polymerizing adhesive (Panavia F) were applied to tooth surfaces before restorative procedures. For the fourth (ferrule) group, no bonding agent was applied, but a 1-mm ferrule preparation was used. In the fifth (ferrule+D-Liner) and sixth (ferrule+Panavia F) groups, respectively, autopolymerizing and dual-polymerizing bonding agents were used in conjunction with the ferrule preparation. After amalgam core fabrication, Ni-Cr full cast crowns for each group were prepared and cemented. All specimens were stored in water for 1 week and thermal cycled 1000 times between 5 degrees and 55 degrees C. A compressive shear load was applied at an angle of 135 degrees to the crown, and the maximum load at fracture (N) was recorded. The data were analyzed with 1-way ANOVA and Tukey Honestly Significant Difference tests (alpha=.05). RESULTS: Significantly higher fracture strength values were demonstrated for the ferrule+Panavia F (652.5 N), ferrule+D-liner (649.1 N) and ferrule (592.4 N) groups, respectively, than for the other groups. The next highest fracture strength values were found for the D-Liner (485.0 N) and Panavia F (486.3 N) groups. The control group (376.6 N) demonstrated the lowest fracture strength in all test groups (P<.001). CONCLUSION: A ferrule preparation or a bonding agent designed for silver amalgam core-dentin bonding can each increase the fracture strength for teeth receiving cast crowns after endodontic therapy and dowel and amalgam core restorations.

Replacement of missing posterior teeth with an all-ceramic inlay-retained fixed partial denture: a case report.

Adhesively luted all-ceramic inlay-retained fixed partial dentures can be a clinical alternative for the replacement of missing posterior teeth in certain situations. This type of restoration allows satisfactory esthetics and reduced tooth preparation compared to a conventional metal-ceramic fixed restoration. This case report describes the use of an inlay-retained fixed partial denture as a conservative alternative for the replacement of missing posterior teeth.

The efficiency of different light sources to polymerize composite beneath a simulated ceramic restoration.

STATEMENT OF PROBLEM: Inadequate polymerization diminishes the physical properties of composite and compromises material strength. Newly developed light-polymerizing units (plasma arc and high intensity halogen) operate at relatively high intensity and are purported to provide optimum properties to composites in a shorter time. PURPOSE: The aim of this in vitro study was to examine the polymerization efficacy of 3 different polymerization units through a simulated ceramic restoration by determining degree of monomer conversion of a composite luting Material. MATERIAL AND METHODS: A conventional halogen light, a plasma arc light, and a high-intensity halogen light were used to polymerize a composite (Variolink II) with or without catalyst. A pressable ceramic block (5 mm in diameter, 2 mm in height) was used as an interface between the polymerizing light tip and composite. The composite/veneer combination was exposed to 2 different polymerization time protocols for each polymerization unit: (1) 20 or 40 seconds for conventional halogen light, (2) 3 or 6 seconds for plasma arc light, and (3) 10 or 20 seconds (under ramp mode) for the high-intensity halogen light. Using different light units, 120 composite specimens were evaluated (n = 5). Fourier transformation infrared spectroscopy was used to determine the level of light polymerization of the resin through the ceramic material with each of the light sources immediately after polymerization or after 24 hours. Degree of conversion was calculated as a percentage of experimentally polymerized versus maximally polymerized composite. The data were analyzed by 4-factor analysis of variance (alpha = .05). Independent t tests (alpha = .05) were used to detect differences between groups defined by the specific interacting variables. RESULTS: Degree of conversion values varied with the light source (P < .05), polymerization type (P < .05), testing time (P < .01), and exposure to each light source (P < .01). Significant interactions were present between light source and polymerization type (P = .00), light source and testing time (P = .007), and polymerization type and testing time (P = .004). The degree of conversion values were significantly higher in dual-polymerized specimens after 24 hours (P < .01), but there were no significant differences in light-polymerized specimens after 24 hours. The degree of conversion values achieved were significantly lower (P < .05) when specimens were dual polymerized by conventional halogen light and measured immediately (31.59 +/- 7.76). The degree of conversion values achieved were significantly (P < .05) higher with dual polymerization by high-intensity halogen measured after 24 hours (65.06 +/- 8.14). There were no other significant differences among groups. CONCLUSION: The highest degree of conversion values of composite were achieved with polymerization by high-intensity halogen. The plasma arc light achieved similar polymerization of composite through ceramic material in a markedly shorter period than conventional halogen light.

Maxillary anterior segmental advancement by using distraction osteogenesis: a case report.

After the first clinical application of distraction osteogenesis (DO) to correct mandibular deformity was reported in 1992, various applications such as maxillary or midface advancement, temporomandibular joint reconstruction, alveolar augmentation, and mandibular widening have been described in the oral and maxillofacial region. Block et al and Altuna et al first examined anterior segmental DO experimentally in the maxilla and reported successful results. After these studies, DO has been used clinically for the total advancement of the maxilla or midface. But no clinical application of DO for maxillary anterior segmental advancement was found by a review of the literature in English. In this article, we present a case with a skeletal Class III abnormality resulting from a maxillary deficiency, which was treated by using anterior segmental DO.