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Aim: To determine if bacteria associated with persistent apical periodontitis induce species‐specific pro‐inflammatory cytokine responses in macrophages, and the effects of this species‐specific microenvironment on osteogenic differentiation. Methodology: Macrophages were exposed to Enterococcus faecalis, Streptococcus oralis, Streptococcus mitis, Fusobacterium nucleatum, Treponema denticola or Tannerella forsythia, and levels of TNF‐α and IL‐1β elicited were determined by immunoassay. Following treatment of MG‐63 pre‐osteoblasts with conditioned media from bacteria‐exposed macrophages, osteogenic differentiation and viability of osteoblasts were analyzed by Alizarin Red Staining and MTS assay, respectively. Statistical analysis was carried out by one‐way anova with the Tukey post‐hoc test. Differences were considered to be significant if P < 0.05. Results: Macrophages exposed to Gram‐positive bacteria did not produce significant amounts of cytokines. F. nucleatum‐challenged macrophages produced up to four‐fold more TNF‐α and IL‐1β compared to T. denticola or T. forsythia. Only conditioned media from macrophages treated with Gram‐negative bacteria decreased mineralization and viability of osteoblasts. Conclusions: Gram‐positive bacteria did not impact osteogenic differentiation and appeared innocuous. Gram‐negative bacteria, in particular F. nucleatum elicited an enhanced pro‐inflammatory response in macrophages, inhibited osteogenic differentiation and reduced cell viability. The findings suggest that the presence of this organism could potentially increase the severity of persistent apical periodontitis. [ABSTRACT FROM AUTHOR]

The susceptibility of five bacterial species to seven dentinal bonding agents was examined in vitro. Agar diffusion tests using filterpaper disks containing 10 μL each of conditioner, primer, or resin were performed on blood agar and mitis salivarius bacitracin agar. Chlorhexidine (0.2%) was used as a positive control. After incubation, zones of inhibited bacterial growth were measured. Of all the compounds tested, Gluma cleanser and Gluma etchant showed the strongest growth inhibition for all bacterial strains. No antibacterial effect was noted for Prisma Universal Bond 2 and Superlux Universal Bond 2 systems. The primers of Gluma, Denthesive and Scotchbond 2 displayed antibacterial activity that, in some cases, was comparable to that of 0.2% chlorhexidine. Zones of inhibition were seen for the resin materials of Scotchbond 2 and Tripton with Streptococcus mutans, Streptococcus sanguis and Actinomyces viscosus. No inhibition was seen after these resins were cured, whereas the antibacterial effect of XR-Bond on S sanguis and A viscosus was not affected by light curing. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Outcome of pulpectomy in 2 treatment sessions with calcium hydroxide as an intracanal dressing was compared to a procedure comprising instrumentation and root-filling in 1 session. STUDY DESIGN: Subjects with a vital pulp condition (N = 256) were recruited to a randomized clinical trial. Outcome parameters included radiographic signs of apical periodontitis and painful symptoms at clinical follow-ups 1 week and 1-3 years after treatment. RESULTS: Of 244 subjects available for final recall, 17 presented with periapical radiolucency. Lesions were evenly distributed among the 2 treatment groups. Postoperative pain recorded 1 week after permanent filling was significantly associated with overfilling (P = .001), with no difference between treatment groups. There was no association with presence of overfilling and radiographic lesion at end point of recall. CONCLUSIONS: Study confirms that pulpectomy may be carried out at a high rate of success if due attention is given to aseptic operating procedures, proper instrumentation and filling. Under these conditions an interappointment dressing with calcium hydroxide does not seem to influence outcome. [ABSTRACT FROM AUTHOR]

OBJECTIVES: The potential of recombinant human bone morphogenetic protein-2 (rhBMP-2) to enhance bone healing following endodontic surgery was tested. The pattern and timing of de novo bone formation and cementum regeneration, and the potential for root resorption and ankylosis to accompany bone formation were evaluated. STUDY DESIGN: Pulpal infections were induced in maxillary and mandibular incisor teeth in young adult Cynomolgus monkeys. The teeth received conventional endodontic treatment immediately followed by surgical root resection. In a randomized split-mouth design, contralateral apical bone defects received rhBMP-2 in absorbable collagen sponge (ACS) carrier or served as sham-surgery controls to provide histological and radiographic evaluations following 1 (mandibular incisors) and 4.5 (maxillary incisors) month(s) postsurgery. RESULTS: At 1 month postsurgery trabecular bone filled the apical bone defects. The newly formed bone appeared considerably more mature and had assumed characteristics of the contiguous resident bone at 4.5 months postsurgery. The resected root tips were almost completely covered by new cementum with a maturing functionally oriented periodontal ligament. Localized inflammatory infiltrates were associated with the filled root canals and extruded root-filling material. Root resorption and ankylosis were not observed. There were no apparent differences in healing patterns between sites implanted with rhBMP-2/ACS and those serving as sham-surgery controls. CONCLUSIONS: Under conditions where the influence of infectious elements and irritation caused by root filling material are minimized, bone formation and cementum regeneration appears rapid following endodontic surgery. rhBMP-2/ACS did not offer an obvious benefit above and beyond that of the native osteogenic potential in this animal model. [ABSTRACT FROM AUTHOR]