Long-term survival estimates of cast gold inlays and onlays with their analysis of failures.

The aim of the present study was to assess the clinical behaviour of cast gold restorations with respect to define a gold control against current and future ceramic and composite restorations. The study sample included 50 patients with 303 cast gold restorations. All restorations were cemented with a non-adhesive technique. A total of 303 restorations were evaluated clinically and radiographically using modified United States Public Health Service criteria. Restorations recorded as having an A- or a B-rating were defined as successful. Of the 303 restorations, 42 were judged as failures, which resulted in a failure rate of 13.8% for a mean observation time (+/- s.d.) of 18.7 ( +/- 9.5) years. The estimated Kaplan-Meier survival rates (s.e.) were 96.1% (+/- 1.1%) at 10 years, 87.0% (+/- 2.2%) at 20 years and 73.5% (+/- 5.4%) at 30 years. In total, biological reasons were counted 25 times in comparison to 17 technical reasons for those 42 failed cast gold restorations, with 17 secondary caries (40%) as the most common biological reason and with 13 retention losses (31%) as the most common technical reason. The endodontically treated tooth was exclusively identified as a risk factor. The restoration type (inlay versus onlay) did not influence the survival rate.

Soft tissue correction of a single-tooth pontic space: a comparative quantitative volume assessment.

STATEMENT OF PROBLEM: Various augmentation procedures are recommended for the correction of localized alveolar ridge defects. However, no study has quantitatively evaluated the results of these procedures to date. PURPOSE: This study compared 2 soft tissue augmentation surgeries commonly used to alter contours of single-tooth pontic space by quantifying 3-dimensional volume changes with the optical projection Moiré method at 1 and 3.5 months after surgery. MATERIAL AND METHODS: Twenty-four patients required surgery. Each patient had a localized alveolar ridge defect, corresponding to a mesial-distal width of 1 single tooth. The defect of 12 patients was corrected with a subepithelial connective tissue graft; the remaining 12 patients were treated by receiving a free full-thickness gingival graft, which included epithelium and connective tissue with fatty tissue. Six unoperated defects of 6 patients formed the control group. For each defect, an impression was made before treatment, at 1 and 3.5 months after surgery to measure the volume changes on the dental casts with a validated projection Moiré system. Volume change was assessed relative to the preoperative dimension at the buccal and crestal aspects of the single-tooth pontic space. RESULTS: At 3.5 months postsurgery, mean volumetric gain for the connective tissue group with 159 mm(3) (SD +/- 80) was significantly greater (P =.027) than for free full-thickness gingival graft group with 104 mm(3) (SD +/- 31). CONCLUSION: The applied projection Moiré method proved its applicability in assessing 3-dimensional volume changes of pontic spaces with a single-tooth width. Volumetric assessment after 1 and 3.5 months revealed significantly greater volume gain with the subepithelial connective tissue graft in comparison to the free full-thickness gingival graft.

The use of protective digit prostheses in management of microangiopathy of fingers.

Small artery occlusive disease (microangiopathy) of the palm and digital arteries may produce ischemia with painful ulcerations on the digits. These ulcerations may contribute to secondary infection and severe intolerance to thermal changes. The use of gauze wrappings to minimize ulceration has been tried; however, it is unhygienic and unsightly. A custom-made digit prosthesis is constructed with medical grade silicone over an artificial finger nail to provide positive seating of the prosthesis. The digit prosthesis is hygienic, esthetically acceptable to the patient and greatly protects ulcerated finger tips.

A retrospective study of combined fixed-removable reconstructions with their analysis of failures.

The survival rate and the reasons for failures of 130 combined fixed-removable reconstructions (CFR), incorporated in 112 patients, were assessed. Each CFR reconstruction was classified depending on its attachments: 76 reconstructions were attached with rigid, precise attachments, and constituted the rigid group; 54 reconstructions were attached with either semi-precision or individual attachments and were defined as the semi-rigid group. Of the 130 reconstructions, 41 were determined as complete successes, 39 as partial successes and 50 as failures, leading to 37 major repairs and to 13 new reconstructions. Three reconstructions failed due to technical reasons, 36 due to biological reasons and for 11 reconstructions, both categories of reasons were responsible for their failure. In total, technical reasons were counted 15 times in comparison to 73 biological reasons for those 50 failed reconstruction, with 29 fractured abutment teeth as the most common biological reason. Within the rigid group, 45 failed reconstructions were observed, whereas within the semi rigid group only 5 failures occurred, leading to an 8-year survival estimate (+/- SD) of 30.1% (+/- 6.9%) for the rigid group and 93.1% (+/- 3.9%) for the semi rigid group. Beside the attachment type, the anatomy of the partially edentulous tooth arch in form of the free-end situation and the dentate opposing jaw were identified as risk factors.

Quantitative measurement of volume changes induced by oral plastic surgery: validation of an optical method using different geometrically-formed specimens.

The purpose of this research was to study the validity and variability of a projection Moiré system, measuring volume differences of geometrically different formed specimens mimicking localized alveolar ridge defects. Nine pairs of specimens were fabricated, each of which simulated a preoperative ridge defect and a corresponding surgically-corrected postoperative ridge defect. All specimen pairs had a mathematically defined form which allowed the accurate assessment of their volume differences by a mechanical 3-D coordinate measuring machine or by a software-controlled milling machine. Measurements achieved with these methods were used as the references for comparison. Six specimen pairs, A1 to A6, possessed a simple rectangular geometrical form which facilitated their fabrication. Three specimen pairs, B1 to B3, were milled and consisted of geometrically more complex 3-D sculptured surfaces, which came closest to a true imitation of a localized ridge defect. An optical measurement system in the form of the projection Moiré was utilized, applying a 4-phase shift technique, and results obtained with this device were regarded as test volumes. The absolute variability of the test volume measurements differed between 0.397 mm3 to 15.872 mm3, corresponding to a relative variability of 0.83% to 2.83%. The mean of the relative variability was within 1.68% for the "A" specimens and 2.15% for the "B" specimens. However, the difference was not significant, probably due to the limited number of "B" specimens. The systematic error of the Moiré measurements in relation to the reference methods was surprisingly low, ranging from -0.12 mm3 to 7.67 mm3. The relative systematic error, expressed as a percentage of reference volume, ranged between 0.06% and -2.23%. The mean of the relative error for the more complex "B" specimens was 1.37%, which was less accurate in comparison to the more simply formed "A" specimens with a relative systematic error of 0.35%. Therefore, in this in vitro model it was possible to measure volume differences of geometrically different formed specimens, mimicking localized alveolar ridge defects, with a validity within 2.2% and with a variability of less than 2.8%.

The thickness of masticatory mucosa in the human hard palate and tuberosity as potential donor sites for ridge augmentation procedures.

The aim of the present investigation was to clinically determine the thickness of masticatory mucosa in the hard palate and tuberosity as potential donor sites for ridge augmentation procedures. In 31 periodontally healthy, fully dentate subjects the masticatory mucosa thickness was assessed by bone sounding with a periodontal probe. Eighteen standard measurement points were defined in the hard palate, located on 3 lines which ran at different distances parallel to the gingival margin. Six positions were designated on each of these 3 lines between the level of the canine and the second molar. In the tuberosity, 6 standard measurement points were defined, located on 2 lines running parallel to the gingival margin at 2 different distances from the distal aspect of the second molar. Three positions were designated on each line. The hard palate and tuberosity were anesthetized by a spray followed by carticain injection with an epinephrine vasoconstrictor of 1:100,000. Data were analyzed to determine differences in gender, between different positions, and between lines, using an analysis of variance and Wilcoxon test. The mucosa of the tuberosity was significantly thicker than in the hard palate region. Gender did not influence the thickness of masticatory mucosa, either in the hard palate or the tuberosity with the exception of the most distant line in the palate. The mucosa was thickest at the mid-distal position of the tuberosity. In the hard palate, mucosa thickness increased with greater distances from the marginal gingiva. The mucosa over the palatal root of the maxillary first molar was significantly thinner than at all other positions in the hard palate. This represents an anatomical barrier in graft harvesting. It was concluded that two different regions may be defined for soft tissue graft harvesting from an anatomic point of view: 1) In the canine-premolar region rather wide and shallow grafts may be harvested. This region extends distally to the first palatal molar root with a significantly thinner mucosa. 2) The tuberosity revealed a significantly more soft tissue thickness in comparison to the hard palate. This region allows the harvesting of deeper grafts, but graft size is limited by the width of keratinized tissue.