Factors Related To Peri-implant Disease In Partially Edentulous Patients Restored With Implant Supported Fixed Prosthesis

[Background]Dental implants have become one of the popular options for the restoration of missing teeth with a highly predictable treatment options and success rate. Its five-year clinical follow-up success rate was 95%, 10-year success rate was 90%, which makes a wide range of implant technology recognition and application. Despite the success rate of dental implants was high, the peri-implant disease was very common. With the rapid growth in the number of implants, peri-implant infection prevention and control consciousness remained weak, the incidence of infections continued to rise, which will affect the long-term success rate of implant. Therefore, early assessment of risk factors, targeted to take measures to prevent the occurrence of peri-implant disease was an effective way to solve this problem, but there are studies abroad mainly by cross-sectional studies and case-control studies, whose results had limited universality and guidance. Risk factors for system validation should include: cross-sectional or case-control study identified potential risk factors, propose clues to the cause; a prospective cohort study was carried out to verify these assumptions factors confirm causality.[Aims]To explore the incidence of peri-implant disease for the implant supported fixed prosthesis in partially edentulous patients and the risk factors related to peri-implant disease occurs. To propose the etiology hypothesis and verify how the periodontal health and periodontal maintenance treatment effect peri-implant disease. In order to provide references for prevention and control. Investigate patients’ subjective satisfaction, and explore the impact of the risk factors of peri-implant disease on patients’ subjective satisfaction, to provide reference for further improve the clinical efficacy of the implant denture. [Methods]1) A retrospective case-control study was conducted between January 2011 to May 2014 at the Department of Prosthodontics, School of Stomatology of the Fourth Military Medical University, cases were selected as dentition defect restored with implant fixed partial denture and satisfied patient inclusion and exclusion criteria for the study, then collected patient’s characteristics through questionnaires and medical records: a history of the system diseases, patients’ oral hygiene habits and periodontal maintenance support treatment and other factors, the application of periodontal probes, shooting X-ray to detect the degree of periodontitis and the health status of implants. Record the patient oral hygiene index and other indicators. Entry all data to Epidate database, after data verification, calculate the incidence of peri-implant disease and the distribution of the factors in the control group and the case group, univariate and multivariate unconditional Logistic regression analysis were used to explore the impact of various factors on the occurrence of peri-implant disease.2) A prospective cohort study was conducted from June 2014 to September 2015 at the Department of Prosthodontics, School of Stomatology of the Fourth Military Medical University, patients were enrolled as dentition defect restored with implant fixed partial denture and satisfied patient inclusion and exclusion criteria for the study. Then collected patient’s characteristics through questionnaires and medical records: a history of the system diseases, patients’ oral hygiene habits and periodontal maintenance support treatment and other factors including pre-implant and post-implant. With application of the periodontal probe to exam the degree of periodontitis and keratinocytes mucosal width, and use X-ray to detect the health status of implant, record the oral hygiene index and other indicators. After the calculation of relevant features, entry all data to Epidate database, and calculate peri-implant disease incidence and incidence density at two points including denture-restored immediate time and follow-up time. Logrank test was used to compare survival rates of implant health, and COX proportional hazard model was used to analyze the impaction of risk factors on peri-implant disease.3) Visual analog scale(VAS) was used to investigate the patients’ satisfaction with implant supported fixed partial dentures. Patients were selected from January 2011 to May 2014 at the Department of Prosthodontics, School of Stomatology of the Fourth Military Medical University who meet the inclusion and exclusion criteria. Using VAS patients’ satisfaction questionnaire to collect 13 indicators like chewing function, aesthetics, phonetics, comfort, subjective satisfaction scores, and to investigate the factors that may affect the patients’ subjective satisfaction. Analyze the relationship between patients’ satisfaction and the risk factors of peri-implant disease. Entry data to Epidate database, calculate the distribution of satisfaction scores and using ANOVA to analyze the influencing factors. [Results]1) A retrospective case-control study showed that: in 131 patients(248 implants), 68 people(110 implants) occurred peri-implant disease. Incidence rate of peri-implant disease on implants level was 44.35%, in patients levels was 51.91%. Univariate analysis showed that men, with a history of bleeding brushing, tooth loss due to periodontal disease, tooth brush only once a day, moderate periodontitis, implant length <10mm and bad proximal contact were risk factors for peri-implant disease. Multivariate analysis showed that: men, tooth brush only once a day, moderate periodontitis, poor contact and implant length <10mm were the independent risk factors for peri-implant disease.2) Prospective cohort studies showed that there were 234 patients(389 implants) with total 2244 person-months of follow-up when implant supported fixed denture immediately. 44 patients(58 implants) occurred peri-implant disease. The incidence rate of peri-implant disease on implants level was 14.72%, and the incidence density was 2.58/100 person-months. The incidence rate of peri-implant disease in patients levels was 18.80%. Univariate analysis showed that male, smoking, drinking, high debris index before implant, high calculus index before implant, tooth brush only once a day, periodontitis and the narrow width of keratinized mucosa were the risk factors for peri-implant disease when implant supported fixed denture restored immediately. Multivariate analysis showed that the risk of severe periodontitis of peri-implant disease was 12 times to periodontal healthy subjects(HR = 12.03, 95% CI: 1.58-91.46); keratinized mucosa width less than 1mm was nearly equal to 2.9 times to width greater than 1mm(HR = 2.87, 95% CI: 1.28-6.42); alcohol drinkers was 2.6 times to patients without alcohol drinkers(HR = 2.62, 95% CI: 1.10-6.25).At follow-up period, there were 214 patients(351 implants) with total 3849 person-months of follow-up. 92 patients(131 implants) occurred peri-implant disease. The incidence rate of peri-implant disease on implants level was 37.32%, and the incidence density was 3.40/100 person-months. The incidence rate of peri-implant disease in patients levels was 42.99%. Univariate analysis showed that males, age, smoking, alcohol drinking, high debris index before implant, high calculus index before implant, tooth brush only once a day, periodontitis, screw retention and poor proximal contact, poor oral health status at follow-up period, high debris index at follow-up period, high-calculus index and bad brushing habits at follow-up period were the risk factors for peri-implant disease. Multivariate analysis showed that mild periodontitis(HR = 2.42, 95% CI: 1.31-4.49), moderate periodontitis(HR = 3.06, 95% CI: 1.45-6.46), severe periodontitis(HR = 27.35, 95% CI: 4.63-161.41), calculus index 1 at follow-up period(HR = 10.89, 95% CI: 1.46-81.49), calculus index 2 at follow-up period(HR = 24.01, 95% CI: 2.77-208.43), screw-retained(HR = 2.68, 95% CI: 1.62-4.43), poor proximal contact(HR = 2.04, 95% CI: 1.14-3.64) were independent risk factor for the occurrence of peri-implant disease.3) Patient satisfaction survey showed that the overall VAS patient satisfaction was 86.96%, 10 indicators like pronunciation, aesthetic, expected effects were higher than 80%; 3 indicators were less than 80% such as the index dare to bite with dental implants was 52.19%, cleaning convenience(75.36%) and review or rework convenience(60.82%). Related factors analysis showed that screw-retained has lower comfort(P<0.05); food impaction was significantly associated with lower chewing satisfaction(P < 0.05); Pronunciation, outcome expectation, choice of implant, expenses for the treatment and the total satisfaction was low in patients who had placed immediately after tooth extraction(P<0.05). Gender, age, education level, type of implant, bone graft, transgingival way and the the type of prosthesis(crown or bridge) had no significant effect on the satisfaction of patients(P>0.05).[Conclusions]1) Periodontitis was the most important risk factor for the occurrence of peri-implant disease, but the degree of influence of different severity and stage of peri-implant disease were different. Effect of severe periodontitis of peri-implant disease was the most prominent, and in the early stage of cultivation have a significant impact on the health of peri-implant; mild to moderate periodontitis impact on the peri-implant disease with prolonged follow-up gradually and showed an increasing trend. Indications should be strictly controlled with severe periodontitis implants, for mild to moderate periodontitis and should be treated accordingly and in stable condition when starting implanting.2) High calculus index after implant restoration was another important risk factor for peri-implant disease. Calculus index reflects the comprehensive oral health status of patients with a certain period, the patient can more fully reflect the maintenance of oral hygiene habits and periodontal treatment situation, its impact on the peri-implant disease as calculus index rises enhanced. The results suggested that patients’ oral hygiene habits and regular maintenance after periodontal maintenance therapy was critical to support the maintenance of healthy tissue around the implant.3) Poor restoration proximal contact and screw retention was related to peri-implant disease. Poor restoration proximal contact relations would lead to food impaction, causing local soft tissue inflammation, and the screw of screw-retained restorations was easy to loose also could cause soft tissue inflammation. We should take attention to restored prosthesis with good proximal contact, and with caution to the indications and design of screw-retained implant prosthesis. Through reducing the local soft tissue inflammation to reduce the adverse effects on the health of the implant.4) Patients treated with implant supported fixed partial restorations were highly satisfied with the treatment. Food impaction, screw retention and immediate implant has a certain impact on the patient’s subjective satisfaction. Through changing peri-implant disease risk factors(food impaction and screw-retained) could improve patients’ satisfaction; and restoring immediately after implant can reduce their impact on the pronunciation of the patient, which may improve the patients’ satisfaction.