Journal of Dental Medicine

Background and Aims: In recent years, dental implants have received special attention in dentistry. Due to the remarkable success of predictable dental implants, there is growing interests in the scientific community from descriptions of implant success toward identify factors associated with implant failure. The purpose of this study was to identify the risk factors associated with implant failure in an objective and statistically valid manner.
Materials and Methods: To address the research purposes, we used a cohort study in which a total of 2368 implants were placed on 1011 patient in the Clinic of Tehran University of Medical Sciences. The predictor variables included demographic variables, the health status and variables are related to implants. The outcome variable of interest was implant failure. The overall implant survival was estimated using the Kaplan-Meier analysis. First, risk factors were identified using Chi-square test and Fisher's exact test and then the Cox proportional hazard regression models were used for more analysis.
Results: The overall 39 month implant survival using the Kaplan-Meier function was 0.99±0.002. The implant location (jaws) (P=0.049) and type of teeth (P=0.011) were found to have significant relation with failure times in Cox proportional hazard model.
Conclusion: According to result of this study, both implant location and type of teeth had effection the failure times so that, the survival in mandible was higher than maxilla. The failure rate was higher in anterior teeth than that of others (molar, premolar, canine and primary).
 

Background and Aims: Cancer is the second most common cause of death in developed countries. The goal of this study was to determine the important epidemiologic factors affecting diagnosis and survival rate of patients with laryngeal SCC, for prevention, control and increase longevity.
Materials and Methods: In this study, all the cases recorded at the Center of Cancer Office of the Iran Ministry of Health in Tehran between 2005-2009 were examined. From 513 cases, 279 that their follow-up was possible by phone or postal address were included in the study. Data collection were performed from questionnaire. The data were analyzed by SPSS version 20. The Kaplan Meier survival curves were utilized and, moreover, the corresponding influential factors were examined by using the Cox regression test.
Results: The mean age of patients were 61.1 years (SD=10.54). The gender of 92.1% of patients were male. The most widely used method for the treatment was a combination of three methods of surgery, radiation therapy, and chemotherapy. The overall five-year survival rate was 75.7% (SD=0.03). The gender, histological differentiation, and professional delay did not exhibit a statistical correlation with the survival rate (P=0.38, 0.14, 0.52), whereas the age and patient delay had a statistically significant relation with the survival rate (P=0.03, 0.07).
Conclusion: The survival rate was lower in older patients. Patient and professional delays were high, which need more attention for improving the quality of life.