In primary teeth root canal treatment, comparison of the antibacterial efficacy of Diode Laser irradiation, PAD application, ozone application and sodium hypochlorite irrigation in in-vitro conditions and examination of clinical success rates

Despite modern advances in the prevention of dental caries and an increased understanding of the importance of maintaining the natural dentition, many primary teeth are stil lost prematurely. However, some of the infected primary teeth can be kept in function until exfoliaton via endodontic therapy. The primary objective of pulp therapy is to maintain the integrity and health of the teeth and their supporting tissues. One of the most important goals of endodontic therapy is the complete elimination of microorganisms from the root canal system. In order to achieve a successful treatment outcome, mechanical instrumentation together with the use of adjunct substances possessing antibacterial properties is essential. The present study consists of two sections including in vitro comparison of the antibacterial efficacy of different methods in primary teeth root canals and evaluate the clinical success rates. The objectives were to compare the antibacterial efficacy of Diode laser, PAD application, ozone application and NaOCl irrigation in primary molar root canals experimentally infected with Enterococcus Faecalis and evaluate the clinical and radiographic success of root canal treatments performed with this applications.The in vitro study sample comprised of 110 root canals prepared from primary incisors or molars extracted for infection or excessive carries and did not have any radiographically visible physiological or pathological root resorption. The root canals were sectioned from the crowns to the cemento-enamel junction and enlarged using stainless steel K-files up to a size of ISO 35. The apical foramina were sealed using flowable composite resin and the teeth were embedded in acrylic resin blocks. The samples were autoclaved for 15 min at 1210C and were infected with E. faecalis (ATCC 29212) for 7 days. The root canals in negative control group were inoculated with sterile TSB.The samples were divided into six groups. In the first group, disinfection was carried out by irrigating with %5.25 NaOCl solution. The second group was irradiated using an 810 nm diode laser (HOYA ConBio Diodent II). In the third group, disinfection was done by using PAD (FotoSan Cms dental, Copenhagen)system. The root canals which were in the fourth group disinfected with ozone gas (Ozonytron-X, Mymed, Germany). The fifth group was left untreated to determine the amount of bacteria which was inoculated in the root canals. The root canals in the sixth group was inoculated with sterile TSB to determine sterilization of working conditions. The experimental and positive control groups consisted of 20 root canals, whereas the negative control group contained 10 root canals. After the disinfection procedures, the samples were taken from canals with sterile paper points for a standart 15 s contact time. After the microbiological evaluation CFU/ ml were enumerated for every root canal sample.The untreated positive control group revealed significantly higher number of bacteria compared with the experimental groups (p=0,0001). NaOCl exhibited the highest antibacterial effect and the difference was found statistically significant (p=0,0001). The samples diode laser group were significantly lower than PAD and ozon groups, however higher than NaOCl with a significant difference (p=0,0001). The number of bacteria in ozone group was higher than PAD group, however the difference was not significant (p >0,05), there is a statistically significant difference between the comparison of other groups (p<0,05).The clinical evaluation part of the study was carried out in Yeditepe University Faculty of Dentistry Department of Pedodontics. The study population consisted of healty, cooperative, children aged 4- 8 years who had at least one primary molar tooth indicated for pulpectomy. For the disinfection procedures the four tested methods (NaOCl, Diode laser, PAD and Ozone) were applied. Then the teeth were restorated with stainless steel crowns.These teeth were examined at 3 month intervals for up to 1 year. Treatment was judged to be successful when the clinical and radiographic criteria were fulfilled. During clinical and radiographic examination, pain, mobility, percussion sensitivity, swelling, formation of fistula, pathologic internal and external resorption, periapical and interradiculer radiolucencies were evaluated and recorded. Clinical and radiographic examination as of the last follow-up showed a success rate of %100.The present is the first study which investigates the antibacterial efficacy of the diod laser, PAD and ozone treatment during the endodontic treatment in primary teeth clinically and in vitro. It is obvious that in vitro studies have limitations in reflecting clinical conditions; therefore it was aimed to support the in vitro findings with the clinical evaluation. Although the diod laser irrigation, PAD and ozon applications were not found as effective as NaOCl irrigation regarding the antibacterial efficacy in the in vitro study; the clinical and radiographic examination findings in one year follow-up showed a %100 success rate for all treatment groups.