Surface roughness and microhardness evaluation of composite resin restorations subjected to three different polishing systems immediately and after 24 h: An in vitro study.

Background: Finishing and polishing of composite resin restorations can be considered two different procedures or two steps of a single procedure. During the finishing procedure, contours are corrected while margins and irregularities are smoothened. The polishing procedures result in the production of a smooth and lustrous finish. Consensus regarding the correct timing for initiating the steps of finishing and polishing after the curing of the composite resins is divided. Some authors support immediate finishing and polishing while other authors support delaying the finishing and polishing procedures. Aim: The aim of this study is to evaluate the surface roughness and microhardness of composite resin restoration subjected to finishing and three different polishing systems immediately and after 24 h. Materials and Method: Eighty composite resin samples were prepared. A Teflon mold was made which was customized for this study having dimensions of 10-mm diameter and 2-mm depth. For the first group of specimens, Group I (n = 20) the composite resin surface was covered with Mylar Strips which acted as control. The other specimens (n = 60) were prepared without the use of a Mylar strip, followed by curing. For all the samples, curing was done with a light-emitting diode for 40 s each. Eighty light-cured samples were divided equally into 4 groups, each group containing 20 samples (n = 20). Out of the 20 samples, in the second, third, and fourth groups, (Kenda C. G. I., Shofu Super-snap X-Treme, and Eve Diacomp Plus Twist) 10 samples were finished and polished immediately after curing and the other 10 samples were finished and polished after 24 h of curing. The samples in Groups II, III, and IV were subjected to finishing by a 12-fluted tungsten carbide bur and were polished according to the respective manufacturer's instructions. The samples were then subjected to quantitative analysis of surface roughness by a noncontact three-dimensional optical profilometer (Bruker GT-Q; Ettlingen, Germany) and qualitative analysis of surface roughness by a scanning electron microscope (Zeiss EVO 18 Special Edition; Carl-Zeiss-Strasse; Oberkochen Germany) at ×10,000 magnification. The samples were also subjected to Vickers microhardness measurement using a microhardness tester (Leica VMHT 001; Walter UHL GmbH, Germany) under 100 g load over 10 s. Conclusion: A. For surface roughness: The samples cured under Mylar strips gave the least surface roughness values (0.25 ± 0.032). Immediate finishing and polishing procedures led to statistically less surface roughness than when finishing and polishing procedures were performed after a delay of 24 h for all polishing systems used B. For microhardness: The samples cured under Mylar strips gave the least microhardness values (57.1 ± 2.03). Delayed finishing and polishing increased microhardness values in all finishing and polishing systems used. Different polishing systems did not have any significant effect on the microhardness values in immediate and delayed finishing and polishing groups.

Comparative evaluation of different probiotic products on salivary Streptococcus mutans and Lactobacillus level in caries risk population.

INTRODUCTION: Dental caries is a multifactorial disease with the main causative organism being Streptococcus mutans and Lactobacillus spp. "Probiotics" are defined as living microorganisms, principally bacteria, which are safe for human consumption and when ingested in sufficient quantities, have beneficial effects on human health, beyond basic nutrition. These can be used to replace the pathogenic strains of bacteria with the nonpathogenic type in the oral cavity thus can help prevent dental caries. AIMS: To evaluate and compare the role of probiotic milk and lozenges on S. mutans and Lactobacillus spp. count on patients who are exposed to probiotics continuously for 7 days. MATERIALS AND METHODS: Sixty volunteers who were prone to caries were divided into three equal groups. Experimental groups were given probiotics daily for 7 days. In Group A, patients were given milk without any probiotics (control); in Group B, probiotic milk is given; and in Group C, probiotic lozenges are given. Saliva samples were assessed on the 1st day and after 7 days of intervention. The collected saliva samples were inoculated on the selected culture media and estimation was done by measuring the colony-forming unit. STATISTICAL ANALYSIS USED: Statistical analysis was performed using Student's paired t-test and multiple comparisons by Tukey's honest significant difference test. RESULTS: There was a significant reduction in salivary S. mutans level in both experimental groups after 7 days (P < 0.05). However, there was no significant difference in Lactobacillus count before and after the intervention. CONCLUSIONS: Probiotics have a role in reducing salivary S. mutans count. Probiotics lozenges showed greater efficacy in reducing salivary S. mutans count than probiotic milk.

Single visit nonsurgical endodontic therapy for periapical cysts: A clinical study.

AIMS: The aim of this study was to assess the outcome of single sitting root canal treatment (RCT) of asymptomatic teeth with periapical cysts. MATERIALS AND METHODS: Ten maxillary anterior teeth showing periapical lesion on the radiograph was further screened by ultrasound with color power Doppler (CPD) for confirmation of a cyst. The average dimension of the lesions ranged from 1.3 to 1.9 cm. Single sitting RCT was performed on all the selected teeth. Postoperative healing was monitored at regular interval of 3 months, 6 months, and 1 year by using subjective feedback, radiograph, and ultrasound with CPD study. RESULTS: Eight among the ten cases showed either signs of complete healing or healing in progress by the end of 6-12 months. CONCLUSIONS: It was observed that single sitting nonsurgical endodontic management of asymptomatic teeth with periapical cyst confirmed by ultrasound was successful in selected cases.

Monitoring of healing by ultrasound with color power doppler after root canal treatment of maxillary anterior teeth with periapical lesions.

AIMS: To assess the reliability of ultrasound imaging coupled with Color Power Doppler for monitoring the healing after nonsurgical endodontic therapy. MATERIALS AND METHODS: Ten asymptomatic maxillary anterior teeth with approximately similar-sized periapical radiolucent lesions of average dimension 1.3 - 1.9 cm, as observed on an intraoral periapical radiograph, and confirmed by ultrasound was selected for the study. After confirming the diagnosis all the teeth were subjected to nonsurgical endodontic treatment. Postoperative healing was monitored using postoperative subjective feedback, a radiograph, and an ultrasound with a color power doppler, at intervals of six weeks, three months, and six months. RESULTS: Eight among the ten cases studied showed signs of healing, with an ultrasound, as early as six weeks postoperatively, but the radiographs showed a noticeable change only at the end of three months. At the end of the follow-up period of three months and six months, the findings in terms of change in the lesion size were the same with both the radiograph and ultrasound. Ultrasonography was able to predict the healing very consistently at all recall periods from six weeks onward providing vital information such as changes in vascularity and bone formation as compared to radiographs. CONCLUSIONS: Ultrasound with Color Power Doppler is an efficient tool for monitoring bone healing as compared to the conventionally employed radiographic method.