Amir Aliramezani, Mohammad Hosein Salari, Mohammad Reza Pourmand, Zeinab Kadkhoda, Abbas Foroushani, Farzaneh Aminharati, Sedigheh Ghourchian, Zahra Pakbaz, Saeed Eshraghi,
Volume 25, Issue 3 (1 2012)
Abstract
Background and Aims: Periodontitis is one of the most common oral diseases with the various incidence rates in different populations. A number of bacteria are considered as the major etiologic agents of periodontitis. The aim of the present study was to determine the prevalence of periodontopathogen bacteria in patients using both PCR and culture techniques.
Materials and Methods: In this study, one-hundred patients (including 62 females and 38 males with an average age of 49±11.5 years) with adult periodontitis referred to periodontics department of School of Dentistry/Tehran University of Medical Sciences were investigated. The samples were taken and sent immediately to the laboratory for culture and molecular evaluation. The PCR was performed using specific primers and the statistical analysis of data was performed using SPSS statistic software and McNemar test.
Results: The results demonstrated that the total detection rate in culture method was 64%. The rate of Aggregatibacter actinomycetemcomitans (Aa) was 28% which was significantly higher than that of Porphyromonas gingivalis (Pg) (6%) and Prevotella intermedia (Pi) (3%). 27% of cases showed mixed bacterial growth. 65% of patients were positive using molecular method. The rate of Aa (30%) was significantly higher than that of Pg (7%) and Pi (5%). The mixed PCR positive rate containing of Aa, Pg and Pi was (23%).
Conclusion: In this study, it was found that most of the bacteria isolated using culture and molecular methods were Aa, Pg and Pi, respectively. Although the detection frequencies of both techniques were similar, the specificity, sensitivity and bacterial detection speed of the PCR technique is obviously higher. Therefore, the use of molecular techniques is strongly recommended. However, both techniques seem to be suitable for microbiological diagnostics.
Abbas Rahimi Foroushani, Nooshin Akbari Sharak, Mohamad Javad Kharazi Fard,
Volume 30, Issue 2 (8-2017)
Abstract
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).
