Background: Recurrent aphthous stomatitis (RAS) is a highly prevalent oral mucosal disease. The management of RAS is quite challenging, and as yet, there is no definitive cure. The present systematic review and meta-analysis assessed the efficacy of a single application of topical doxycycline for the management of RAS. Methods: A comprehensive online search of PubMed, Scopus, Embase, and Web of Science databases was conducted to identify all relevant studies published up to March 31, 2019. All randomized clinical trials that assessed the efficacy of a single application of topical doxycycline in the management of RAS were included. Primary outcome measures were pain scores and/or healing time, while secondary outcomes included the associated side effects. RevMan 5.3 software was used for data analysis. Results: Five clinical trials fulfilled the eligibility criteria, three of which were included in the meta-analysis. All of the included studies found doxycycline effective in alleviating signs and symptoms of RAS. The results of the pooled 3 studies revealed a statistically significant decrease in the healing time in favor of the doxycycline group as compared to the control groups (I 2 = 51%; MD:-1.77, 95% CI: − 2.11, − 1.42, P <0.00001); however, the results showed no significant differences between doxycycline and control groups with regard to pain reduction (I 2 = 96%; MD:-1.28, 95% CI: − 2.83, 0.27; P = 0.11). Conclusion: Although still inconclusive, the available evidence suggests that a single application of topical doxycycline might be effective for reducing signs and symptoms of RAS. However, owing to the limited number of the included studies, further well-designed clinical trials with adequate sample sizes are required to discern the clinical efficacy of topical doxycycline in patients with RAS.

Objective:The purpose of this study was to investigate the importance of pullout location and clasp types in two different environments to dislodge the clasp.Materials and Methods:Mandibular test models with natural premolars and molar teeth were used to test four types of clasp (each 12) (Akers, Rest plate Akers, Half and Half, and Ring clasp) with three different pullout location for each type (ring on the rest, loop on the saddle, and wax arising from both rests) in dry and natural fresh saliva environment. Each clasp was pulled out 10 times with a crosshead speed of 10 mm/min, and the force required to withdraw each was measured.Statistical Analysis Used:A one-way ANOVA and Tukey test were used.Results:The ring on the saddle pullout location has the highest retention force while ring on the rest was the lowest. In addition, ring clasp has the highest retention force.Conclusion:Clasp type and pullout location had a significant effect on the retentive force.

BackgroundOne of the major innovations in endodontics has been the introduction of nickel-titanium (NiTi) alloy. This study evaluated the surface topographical changes of two different surface treatments rotary instrument after instrumentation and sterilization.Material and Methods240 Extracted teeth were included in this study. 90 new AlphaKite and Revo-S NiTi rotary instruments were selected and divided into two groups (Group A 45 AlphaKite and group B 45 Revo-S). Each group were divided into three subgroups: (A1, B1) n=5 files were used as a control, (A2,B2) n=20 files were used to prepare three root canals using endodontic rotary motor then sterilized by autoclave for one cycle under 121°C at 15 psi for 30 minutes and (A3,B3) n=20 files were used to prepare nine root canals using the same rotary system then sterilized by autoclave for three cycles under 121°C at 15 psi for 30 minutes. Files were examined under scanning electron microscopy.ResultsOn examining the AlphaKite, A1 revealed gross machining grooves on their surface with no pits, A2 showed disruption of cutting and A3 showed microcracks and deepening of the machining grooves. B1 showed a smoother surface with few machining grooves, B2 showed dulling and blunting of the cutting edges was predominant and B3 files showed plastic deformation in the form of unwinding of the flutes.ConclusionsThe defects were less distributed along the electropolished Revo-S files than the physical vapor deposition AlphaKite. Key words:Endodontic instruments, electropolished, rotary, sterilization.