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Philip Watson

Publications and source records attributed to Philip Watson.

6 recordsLinked to original sources
PubMed2002

Ten-year results of a prospective study using porous-surfaced dental implants and a mandibular overdenture.

BACKGROUND: Numerous investigators have used osseointegrated dental implants as retention for mandibular overdentures, but few have reported 10-year outcomes or incorporated carefully standardized radiographs to document crestal bone loss. PURPOSE: The purpose of this study was to use a prospective clinical trial design to assess the performance of short sintered porous-surfaced dental implants with a mandibular complete overdenture when all patients in the trial had undergone 10 years of continuous function. MATERIALS AND METHODS: Fifty-two fully edentulous patients, most with advanced alveolar ridge resorption, each received three free-standing Endopore implants (7-10 mm in length, mean length, 8.7 mm; Innova Corporation, Toronto, ON, Canada) in the mandibular symphysis region. After 10 weeks of submerged healing, these implants were used to support an overdenture. Carefully standardized radiographs, using a customized stainless steel filmholder attached to each implant and the x-ray tube, were collected at baseline, 3 months, 6 months, yearly to 5 years, and then again at 7and 10 years. RESULTS: Life table analysis revealed a 10-year implant survival of 92.7% and a mean annual bone loss after year 1 of 0.03 mm. CONCLUSION: Short free-standing dental implants with a sintered porous surface used for implant fixation are a predictable and effective means of retaining a mandibular overdenture in patients with advanced mandibular ridge resorption.

Alveolar Bone Loss↗
PubMed2002

Demonstration of immunoglobulin G, A, and E autoantibodies to the human thyrotropin receptor using flow cytometry.

Human TSH receptor (TSHR) autoantibodies with biological activity result in thyroid dysfunction, but antibodies that simply bind do not. We have applied flow cytometry to the measurements of IgG, IgA, and IgE immunoreactivity to the TSHR in patients with Graves' disease (GD) and thyroid eye disease (TED) and in normal controls. CHO cells stably expressing the extracellular domain of the TSHR with a glycophosphatidylinositol anchor were produced and found to express approximately 4 times as many receptors, but of similar affinity, as JP09 in TSH binding studies. Substantial increases in median fluorescence and peak channel fluorescence were obtained by flow cytometry using TSHR monoclonal antibodies on the glycophosphatidylinositol cells. IgG autoantibodies were demonstrated in 55 of 65 untreated GD patients, 3 of 25 normal subjects, and 4 of 8 atypical TED sera (negative for TSHR autoantibodies with biological activity) by flow cytometry and correlated poorly with thyroid-stimulating antibodies. IgA antibodies were present in 1 of 12 normal, 1 of 7 treated GD with TED, and 3 of 8 atypical TED sera. IgE binding was observed in 1 of 12 normal, 2 of 8 treated GD without TED, 1 of 6 treated GD with TED, and 0 of 8 atypical TED sera. In conclusion, we have demonstrated autoantibodies that bind directly to the TSHR in the majority of GD patients and in 50% of patients with atypical TED and a small number of normal controls lacking TSHR antibodies that affect function. Although predominantly IgG lambda, TSHR autoantibodies of the IgA and IgE isotypes are also detectable.

Adult↗
PubMedDate not supplied

An assessment of crown-to-root ratios with short sintered porous-surfaced implants supporting prostheses in partially edentulous patients.

PURPOSE: Implant length, implant surface area, and crown-to-root (c/r) ratio and their relationship to crestal bone levels were analyzed in 2 groups of partially edentulous patients treated with sintered porous-surfaced dental implants. MATERIALS AND METHODS: One hundred ninety-nine implants were used to restore 74 partially edentulous patients with fixed prostheses. Implants were categorized according to their length ("short" versus "long") and estimated surface area ("small" versus "large"). "Short" implants had lengths of 5 or 7 mm, while "long" implants were either 9 or 12 mm in length. "Small" implants had estimated surface areas of < or = 600 mm2, while "large" implants had estimated surface areas > 600 mm2. Other data collected included c/r ratio (measured on articulated diagnostic casts), whether or not the implants were splinted, and standardized sequential radiographs. RESULTS: The mean c/r ratio was 1.5 (SD = 0.4; range 0.8 to 3.0), with 78.9% of the implants having a c/r ratio between 1.1 and 2.0. Neither c/r ratio nor estimated implant surface area (small or large) affected steady-state crestal bone levels. However, implant length and whether the implants were splinted did appear to affect bone levels. Long implants had greater crestal bone loss (0.2 mm more) than short implants; splinted implants showed greater crestal bone loss (0.2 mm more) than nonsplinted ones. These differences were statistically significant. DISCUSSION AND CONCLUSIONS: Sintered porous-surfaced implants performed well in short lengths (7 mm or less) in this series of partially edentulous patients. The data suggested that long implants and/or splinting can result in greater crestal bone loss; longer implants and splinted implants appeared to favor greater crestal bone loss in this investigation. These conclusions are, of course, specific to the implants used and would not be relevant to other implant types.

Adult↗