Indocyanine Green-Assisted and LED-Light-Activated Antibacterial Photodynamic Therapy Reduces Dental Plaque.

AIM: This study aimed to determine the feasibility and first efficacy of indocyanine green (ICG)-assisted antimicrobial photodynamictherapy (aPDT) as activated using LED light to the dental plaque. METHODS: Fifteen healthy adults were assigned to this four-day randomized study. After rinsing with ICG, 100 J/cm2 of 810 nm LED light was applied to the aPDT-treatment area. Plaque area and gingival crevicular fluid (GCF) matrix metalloproteinase-8 (MMP-8) were measured, and plaque bacteriomes before and after the study were analyzed using 16S rRNA sequencing. RESULTS: aPDT administration was preformed successfully and plaque-specifically with the combination of ICG and the applicator. Total plaque area and endpoint MMP-8 levels were reduced on the aPDT-treatment side. aPDT reduced Streptococcus, Acinetobacteria, Capnocytophaga, and Rothia bacteria species in plaques. CONCLUSION: ICG-assisted aPDT reduces plaque forming bacteria and exerts anti-inflammatory and anti-proteolytic effects.

Radiographic outcome of root canal treatment in general dental practice: tooth type and quality of root filling as prognostic factors.

OBJECTIVE: This study evaluated the radiographic outcome of root canal treatments (RCTs) performed by general dental practitioners (GDPs) with focus on tooth type and quality of root filling. MATERIALS AND METHODS: The target population included all patients receiving root filling by GDPs in City of Helsinki in 2010-2011. Equal numbers of each tooth type (anteriors, premolars, molars) by jaw were included, resulting in 426 teeth. Pre- and post-operative periapical radiographs were assessed to evaluate periapical status and quality of root filling. Statistical evaluation utilized Chi-squared tests, Cohen's kappa and logistic regression modelling. RESULTS: The overall success rate of RCT was 67.4%, being 76.8%, 69.7% and 55.6% (p < .001) for anteriors, premolars and molars, respectively. The quality of root fillings varied by tooth type (p < .001); optimal fillings were least frequent (43%) in molars. In multifactorial analysis, RCTs were more likely to succeed in non-molars (OR = 1.8), in teeth with optimal root fillings (OR = 3.6) and in teeth without apical periodontitis (OR = 3.2). CONCLUSION: The quality of root fillings and radiographic outcome of RCTs varied considerably according to tooth type; success was least likely in molars. Improvement is needed in quality of RCTs by GDPs.

Impact of type of tooth on outcome of non-surgical root canal treatment.

OBJECTIVES: We assessed the impact of type of tooth on the outcome of root canal treatment (RCT) according to factors potentially weakening the prognosis such as preoperative apical periodontitis (AP) and treatment modality (primary or secondary RCT). MATERIALS AND METHODS: We scrutinized patient documents including pre- and postoperative radiographs of 640 permanent teeth receiving non-surgical RCT at Helsinki University Clinic in 2008-2011. Of teeth, 44% were molars, 32% premolars, and 24% anterior teeth. Patients' mean age was 51.5 years; 51% were male. AP was present in 60.5% of teeth preoperatively. We used the periapical index (PAI) to assess the radiographs and defined radiographically "healthy" and "healing" cases as successful. Statistical evaluation included chi-squared tests, Fisher's exact tests, t tests, and logistic regression modeling. RESULTS: The overall success rate (SR) was 84.1%; 88.3% for primary and 75.5% for secondary RCT (p < 0.001). The SRs for anterior teeth, premolars and molars were 85.6%, 88.8%, and 79.7%, respectively. Teeth with and without AP had SRs of 77.3% and 94.5%, respectively (p < 0.001). The RCTs were more likely to succeed in anterior teeth and premolars than in molars (OR 1.7; 95% CI 1.1-2.7) and in females than in males (OR 1.9; 95% CI 1.2-3.1). CONCLUSIONS: Apart from existing AP and retreatment scenario, also, the type of tooth and gender had a significant influence on the outcome of RCT in this study. CLINICAL RELEVANCE: The prognosis of RCT varies by type of tooth; special attention should be given to RCT of molar teeth.

Crystalline surface protein of Peptostreptococcus anaerobius.

The surface ultrastructure of three anaerobic Gram-positive cocci frequently encountered in oral infections, Peptostreptococcus micros, P. magnus and P. anaerobius, was studied. The type strains of P. micros (DSM 20468) and P. anaerobius (ATCC 27337), several clinical isolates of both species and the type strain of P. magnus (DSM 20470) were included. Thin-sectioned cells studied by electron microscopy revealed a homogeneous layer outside the peptidoglycan layer in P. anaerobius. In P. micros and P. magnus a more amorphous layer was present. No periodic structures were seen in negatively stained whole cells of these three species. However, in freeze-etched cells of P. anaerobius a crystalline surface protein layer (S-layer) was detected. No periodicity was seen in any of the P. micros strains or the P. magnus type strain by the methods used, but a periodic pattern was observed in negatively stained specimens of cell wall fragments of sonicated P. anaerobius cells. No capsular material was visible outside the S-layer in P. anaerobius. The cells of the Peptostreptococcus spp. were extracted for 30 min with detergents and urea. One per cent SDS and M urea both extracted a major 78 kDa protein from all strains of P anaerobius. Extraction of P. micros and P. magnus cells did not reveal any major protein bands comparable to that of P. anaerobius. Surface biotinylation of cells followed by Western blotting and detection by alkaline-phosphatase-conjugated extravidin showed strong staining of the 78 kDa band in P. anaerobius, further indicating that this molecule is located on the surface of the cell and is the S-protein.(ABSTRACT TRUNCATED AT 250 WORDS)