The effects of local factors on the survival of dental implants: A 19 year retrospective study / 대한치과보철학회지

PURPOSE: The aim of this retrospective study was to provide long-term data about the correlation between multifactorial local factors and the survival of implants. MATERIAL AND METHODS: During 19 years (1991 to 2009), 2796 implants were placed in 879 patients. From dental charts and radiographs, the following data were collected: patient's age at implant placement, gender, implant system, surface, length, diameter, location of implant placement, bone quality, primary stability, type of prosthesis. The correlations between these data and implant survival were analyzed. Statistical analysis was performed using Kaplan-Meier survival analysis, Chi-square test, odds ratio. RESULTS: 1. Among the 2796 implants, 150 implants failed that resulted in a cumulative survival rate of 94.64%. The cumulative survival rate of smooth surface implants (91.76%) was lower than rough surface implants (96.02%). 2. Anatomic location, implant surface, diameter of smooth surface implant, primary stability, type of prosthesis, patient's age and gender were significantly associated with implant survival (P < .05). 3. No significant difference in implant survival was found in relation to the following factors: implant length, bone quality, diameter of rough surface implants and type of rough surface according to implant manufacturer (P < .05). CONCLUSION: Local factors such as anatomic location, implant surface, diameter of smooth surface implant, primary stability and type of prosthesis have a significant effect on implant survival.

Early Failure of Total Hip Arthroplasty with Hydroxyapatite-Coated Smooth Surface Acetabular Component / 대한정형외과학회잡지

PURPOSE: To evaluate the early intermediate outcomes of total hip arthroplasty using hydroxyapatite (HA)-coated smooth surface hemispherical acetabular component. MATERIALS AND METHODS: Seventy total hip arthroplasties were performed, in 63 patients, using a HA-coated smooth surface hemispherical acetabular component consecutively between June 1993 and August 1996. Fifty-four cases were followed at an average of 71 months. The mean age at the time of arthroplasty was 49 years old. Clinical results were evaluated using the modified Harris hip score, and the radiologic results were evaluated in terms of stability, polyethylene wear rate, and osteolysis around the acetabular component. RESULTS: The mean preoperative Harris hip score of 50.9 was improved to 82.2 points at the most recent follow-up. Pelvic osteolysis was found at 18 cases (33%) and the mean polyethylene wear rate was 0.15 mm/year. Eight acetabular components (15%) were unstable radiologically and 7 acetabular components (13%) were revised. CONCLUSION: Total hip arthroplasty using HA-coated smooth surface hemispherical acetabular component showed accelerated polyethylene wear rate, which was accompanied by a high incidence of osteolysis, and a high loosening rate due to failure of bony ongrowth at early midterm.

Bone Ongrowth of Hydroxyapatite-Coated ABG Acetabular Cups / 대한정형외과학회잡지

PURPOSE: To evaluate the efficacy of the smooth surface hydroxyapatite (HA)-coated acetabular cup in total hip arthroplasty. MATERIALS AND METHODS: From March 1992 to June 1998, 289 smooth surface HA coated acetabular cups were implanted. This study included 29 retrieved cups that had been in situ for an average of 54.9 months. The three dimensional acetabular cups were converted into two dimensional figures using a digital camera, and the ratio of bone ongrowth and HA absorption were calculated using a computer imaging analysis system (analySIS-pro 3.0, Soft Imaging System GmbH, Germany). The central hole and the peripheral 12 holes were excluded from total surface area of the cup, which was divided into 3 surfaces by 2 circular grooves. RESULTS: Bone ingrowth was noted in 26 of the 29 cases; in 11 cases (37.9%) on the central surface, 12 cases (41.3%) on the middle surface and 8 cases (27.5%) on the peripheral surface. Bone ongrowth was noted in 22 cases (75.8%) on the medial groove and in 21 cases (72.4%) on the lateral groove. The average rate of bone ongrowth was 13.8 percent. HA absorption was noted in all cases and averaged 60.5 percent. CONCLUSION: Bone ongrowth on the smooth surface HA-coated acetabular cup was very scant. Bone ongrowth was seen more on the grooves than on the surfaces. We believe that a rough surface would enhance bone growth on HA-coated acetabular cup.