Prosthetic rehabilitation of a mandibular gunshot defect with an implant-supported fixed partial denture: a clinical report.

This report describes the clinical evaluation of a patient with a mandibular gunshot defect and the prosthodontic treatment with an implant-supported screw-retained fixed partial denture. Treatment included cemented crowns for 2 maxillary implants and an implant-supported screw-retained fixed partial denture supported by 8 mandibular implants. Despite the implant malposition limitations, the esthetic and functional demands of the patient were fullfilled.

Analysis of strain around endosseous dental implants opposing natural teeth or implants.

STATEMENT OF PROBLEM: Natural teeth and implants have different force transmission characteristics to bone. PURPOSE: The purpose of this study was to compare strains induced around a natural tooth opposing an implant with strains around occluding implants under static and dynamic loads. MATERIAL AND METHODS: Occlusion was created between a natural molar tooth and an implant in 1 side, and 2 implants in the contralateral side of acrylic resin models of both jaws. Strain-gauges were bonded around the neck of the natural tooth and implants, and strains were measured under 75 N and 100 N static axial and lateral dynamic loads in separate load situations using a data acquisition system at sample rate of 1000 Hz. The strain data of the natural tooth and implants were compared for each load by Kruskal-Wallis testing followed by the multiple comparison test (alpha=.05). RESULTS: Compressive strains were induced around natural tooth and implants as a result of static axial loading, whereas combinations of compressive and tensile strains were observed during lateral dynamic loading. Strains around the natural tooth were significantly lower than the opposing implant and occluding implants in the contralateral side for most regions under all loading conditions ( P <.05). There was a general tendency for increased strains around the implant opposing natural tooth under higher loads and particularly under lateral dynamic loading ( P <.05). CONCLUSION: Under static and dynamic loads, strain magnitudes around a natural tooth were significantly lower than that of an opposing implant and occluding implants in the contralateral side.

Effect of toothbrushing on the material loss, roughness, and color of intrinsically and extrinsically stained porcelain used in metal-ceramic restorations: an in vitro study.

PURPOSE: Because of abrasion by toothbrushing, dental materials in the oral cavity are subjected to substance loss to a different extent depending on the hardness of the material. This study investigated the color-change effect of substance loss and change of roughness resulting from toothbrushing of internally and externally stained metal ceramic. MATERIALS AND METHODS: Metal-ceramic specimens 15 mm in diameter and 2 mm thick were made. Blue colorant suspension was applied over the enamel porcelain (enamel-stained), in the body porcelain (dentin-stained), and over the opaque porcelain (opaque-stained). One group was not stained. Each group was made up of seven samples. All specimens were brushed in an experimental device. Material loss, roughness measurements, and spectrophotometric evaluations were made before and after brushing. Overall color change, chroma change, and value change were calculated with the use of the CIE-LAB uniform color scale. RESULTS: Significant substance loss as a result of brushing was observed. No significant differences between chroma changes, between value changes of different groups, or between overall color changes of dentin- and enamel-stained groups were found. The difference between overall color changes of opaque-dentin and opaque-enamel stained groups was statistically significant. CONCLUSION: Staining should be done as deeply as possible to obtain durable color appearance.