Isolation, characterization and complete genome analysis of a novel bacteriophage vB_EfaS-SRH2 against Enterococcus faecalis isolated from periodontitis patients.

Periodontitis is a chronic inflammatory condition that can damage soft tissues and supporting teeth. Enterococcus faecalis is an opportunistic pathogen usually living in the oral cavity and plays a critical role in apical periodontitis that significantly threatens human health. The use of bacteriophages as an alternative way to eliminate bacterial infections is a promising approach. E. faecalis was isolated from the depth of dental packets of patients with periodontitis. Antimicrobial susceptibility was tested using 16 antimicrobial agents. Also, a specific virulent bacteriophage (vB_EfaS-SRH2) with an irregular pentagonal morphology of the head and a non-contractile tail belonging to the Siphoviridae, was isolated from wastewater in East of Isfahan, Iran, and its physiological and genomic specifications were investigated. The genome was double-strand DNA with 38,746 bp length and encoded 62 putative ORFs. In addition, eight Anti-CRISPERs and 30 Rho-dependent terminators were found. No tRNA was found. It had a short latent period of 15 min and a large burst size of ~ 125. No undesirable genes (antibiotic resistance, lysogenic dependence, and virulence factors) were identified in the genome. Based on physiological properties and genomic characteristics, this phage can be used as a suitable choice in phage therapy for periodontitis and root canal infection.

Pulp Response following Direct Pulp Capping with Dentin Adhesives and Mineral Trioxide Aggregate; An Animal Study.

INTRODUCTION: Pulp vitality and its continuous dentin prodution are essential for long-term success of direct pulp capping (DPC). The aim of present study was to evaluate the histopathological response of the canine pulp following DPC using either different dentin adhesive resins (DAR), calcium hydroxide (CH) or mineral trioxide aggregate (MTA). METHODS AND MATERIALS: DPC was done on 72 dog's teeth using 6 types of dental materials (n=12) (4 types of DAR, white MTA and CH). Therefore, six healthy dogs were anesthetized and 2 teeth from each dog were allocated to either type of mentioned DPC agents. The dental pulps were exposed mechanically by drilling in the center of class V cavities. The different types of capping materials included DARS (Clearfil S3 Bond, Optibond FL, Single Bond and Clearfil SE Bond), white MTA and CH. After 7, 21 and 63 days, two dogs were euthanized in each interval. Microscopic evaluations were done according to following criteria: intensity of inflammation, presence of necrosis and formation of hard tissue. The recorded data were analyzed by the Kruskal-Wallis, Friedman, Cochran's and Fisher's exact tests using SPSS software version 12 at significant level of 0.05. RESULTS: No significant differences were found regarding necrosis among DPC materials (P>0.05). However, MTA caused higher amount of hard tissue formation after 63 days in comparison with 21 days. CONCLUSION: MTA provided the highest degree of hard tissue formation after 63 days. However, further studies should be performed for administering a definitive material.

Recharge pattern of contemporary glass ionomer restoratives.

BACKGROUND: As glass ionomers have the ability to reload fluoride from outside sources, the aim was to compare the recharge pattern of six glass ionomer cements after exposure to fluoride. MATERIALS AND METHODS: Fuji VII, Fuji IX, Riva Pink, Riva Bleach, Ketac Fil and Fuji IX Extra were investigated. The fluoride-containing materials used were tooth paste and mouth wash (Colgate). Specimens of each material (n=15) were immersed separately in deionized water for 59 days. Then the samples of each material were divided into three groups of five each. Two groups were recharged for 2, 20 and 60 min daily during three consecutive weekly intervals and then no treatment for one week. The third group was used as control. Fluoride release measurements (µg/cm(2)/day) were made in every 24 h. One-way and repeated measures analysis of variance tests were used. RESULTS: Tooth paste recharged materials showed higher level of recharge. On day 1, the difference of fluoride release from different treatment groups of different materials except for Fuji IX Extra were not significant (P>0.05). On days 7 and 14, the differences observed were significant (P<0.05) for all materials except for Fuji VII (tooth paste versus mouth wash) and Trial Fuji IX (mouth wash versus control) and on day 14 for Rvia Pink (mouth wash versus control). On days 21 and 28, the differences observed were significant for all the materials (P<0.05) except for Riva Pink (toothpaste versus mouth wash), Riva Bleach, Ketac Fil and Trial FujiI X (mouth wash versus control) on day 28. CONCLUSION: A time tabled schedule of application of fluoride-containing materials could help to achieve high fluoride release.