Peri-implant conditions and their relationship with periodontal conditions in Chinese patients: a cross-sectional study.

OBJECTIVES: To analyze the relationships between peri-implant conditions and periodontal conditions in Chinese patients with dental implants in place for at least 1 year. MATERIAL AND METHODS: Seventy-six patients (mean age, 41 +/- 10 years; range, 21-69 years) who received placement of 120 dental implants (Straumann((R)) ), (mean 1.6 implants per subject; range, 1-5 implants per subject) after a mean period of 25 months (range, 12-66 months) responded to recall. Clinical examinations were performed around the implants and natural teeth. Periapical radiographs were taken by the long cone technique for implants, and radiographic bone level (BL) was measured. Comparisons of the peri-implant conditions were performed between the patients with different periodontal conditions by t-test and chi-square test. The relative risk of periodontal condition as a risk factor for peri-implant conditions was analyzed by logistic regression. RESULTS: Subjects who presented with >/=5% sites with probing depth (PD) >/= 4 mm and >/=30% sites with bleeding on probing (BoP) in the dentition showed significantly poorer peri-implant conditions (58% vs. 18% subjects who had maximum modified gingival index (mGI) 2 or 3, P = 0.003; 94% vs. 62% subjects who had maximum PD >/= 4 mm, P = 0.008; 100% vs. 79% subjects who had BoP, P = 0.044; mean PD 3.36 +/- 0.66 vs. 2.75 +/- 0.66 mm, P = 0.002; and sites% with BoP 68 +/- 23% vs. 36 +/- 31%, P < 0.001), as compared with those who had <5% sites with PD >/= 4 mm and <30% sites with BoP on the remaining teeth. The relative risk for subjects with the more severe and extensive periodontal conditions compared to those with better periodontal conditions to have PD >/= 5 mm with BoP at peri-implant sites was 23.3 (P = 0.003, 95% CI, 2.8-192.3. CONCLUSIONS: The peri-implant conditions were significantly related to the periodontal conditions around the remaining natural teeth, which implies that control of periodontal disease is essential for successful implant treatment.