Comparing fibroblast attachment in root surface scaling with Er, Cr:YSGG laser versus ultrasonic scaler: A SEM study.

BACKGROUND AND OBJECTIVES: The regeneration of periodontal support is the main concern in periodontal therapy. The aim of this in vitro study was to investigate the fibroblasts attachment on root surfaces after scaling with Er, Cr:YSGG laser and ultrasonic instruments using scanning electron microscopy (SEM). METHODS: 72 root plates of ∼6 × 4 × 1 mm3 in dimension were prepared from 27 single-rooted human mature teeth and were then divided into four groups. One group irradiated with a G6 tip of Er, Cr:YSGG laser (2.78 µm, 0.75 W, pulse duration of 140 µs, repetition rate of 20 Hz) for 5 to 7 s, and the other groups were scaled with ultrasonic alone or laser-ultrasonic. The control group was subjected to neither laser nor ultrasonic scaling. Subsequently, Viability and proliferation rates were done using MTT assay on days 3 and 5. Finally the cell attachment was observed using SEM. RESULTS: The data derived from MTT and cell-attachment analysis indicated that laser-ultrasonic scaling tended to increase cell-viability by the lapse of time (within 3-5 days), with significantly better cell-attachment compared with other groups on days 3 and 5 (p < .05). The comparison of the difference in fibroblast cell attachment rate on both the third and the fifth day with independent T-Test indicated a significant rise on the fifth day compared to the third day of study (p < .05). CONCLUSION: Indeed, both Er, Cr:YSGG laser and ultrasonic scaling may promote fibroblast attachment on dentinal root surfaces more than laser or ultrasonic scaling alone.

Evaluation of fibroblast attachment in root conditioning with Er, Cr:YSGG laser versus EDTA: a SEM study.

The regeneration of periodontal support is a main concern in periodontal therapy. This study aims to investigate the efficacy of Er, Cr:YSGG laser and EDTA based conditioning in attachment of fibroblast on root surfaces. This in vitro study was conducted on 81 root plates (6 mm × 4 mm × 1 mm) prepared from 27 single-rooted human mature teeth. The samples were divided into three groups: (1) Er, Cr: YSGG laser conditioning with a G6 tip (2.78 µm, 0.75 W, pulse duration of 140 µs, repetition rate of 20 Hz) for 5-7 s; (2) EDTA conditioning (17%, pH: 8) for 1 min; and (3) the control group which were exposed neither to EDTA nor laser. The viability and proliferation rates assessments were performed using MTT assay on days 3 and 5. In addition, the level of cell attachment was studied using scanning electron microscopy. The data indicated Er, Cr:YSGG conditioning increased cell viability by lapse of time (from days 3-5), with significantly better cell attachment compared to the other groups on days 3 and 5 (P < 0.05). In addition, increasing cell attachment in the EDTA conditioning group compared with the control group was statistically significant on day 5 but not on day 3 (P < 0.05). In conclusion, Er, Cr:YSGG laser conditioning can promote enhance fibroblast attachment on dentinal root surfaces more than EDTA.

Antibacterial effect of Iranian green-tea-containing mouthrinse vs chlorhexidine 0.2%: an in vitro study.

PURPOSE: Considering the antioxidant, anti-inflammatory and antimicrobial properties of green tea, this study aimed to evaluate the antibacterial effect of mouthrinses containing green tea extract vs 0.2% chlorhexidine on selected microorganisms in vitro. MATERIALS AND METHODS: The antibacterial activity of both mouthrinses and the pure green tea extract was assessed by using disk diffusion and the minimal inhibitory concentration (MIC) methods against five microorganisms: Streptococcus mutans, Streptococcus sanguis, Enterococcus faecalis, Pseudomonas aerogenosa and Escherichia coli. Growth inhibition zones were measured in mm after 24 h of incubation at 37°C. The two mouthrinses were assessed at concentrations of 1, 2, 4, 8, 16, 32, 64, 128, 256 and 512 mg/ml to determine the MIC, which was interpreted as the lowest concentration of the agent that completely inhibited the growth of the test species. RESULTS: 0.2% chlorhexidine produced a larger zone of growth inhibition than did the mouthrinse made of green tea extract (P < 0.01). Paradoxically, the growth inhibition zones of the tested bacteria were significantly larger in pure extract of green tea than in 0.2% chlorhexidine (P < 0.01). The chlorhexidine mouthrinse inhibited the growth of all tested species and exhibited significantly lower MICs than did the green tea mouthrinse (P < 0.01). CONCLUSIONS: Even though the mouthrinse made with green tea extract presented an in vitro antimicrobial activity inferior to 0.2% chlorhexidine, the pure extract had considerable bactericidal effect.

Tobacco cessation practices of senior dental students in Iran.

OBJECTIVE: Tobacco use is prevalent in Iran, especially among men. The aim was to assess cessation practices and identify perceived barriers to delivery of tobacco cessation services by Iranian senior dental students. DESIGN: Descriptive, cross-sectional study. SETTING: Iran, Schools of Dentistry, 2009-2010. PARTICIPANTS: 370 (response rate 82%) officially registered senior dental students selected through stratified random sampling. INTERVENTION: Students at 11 dental schools throughout the country completed the survey. MAIN OUTCOME MEASURE: Students' practice of the US Clinical Practice Guideline 5 As (ask, advise, assess, assist, arrange); interest in training; intention and barriers addressing tobacco use in dental settings. RESULTS AND CONCLUSIONS: Respondents were primarily female (67.8%). The students were far more likely to be actively involved in asking, advising and assessing patients to quit than in assisting and arranging. Most respondents (68.5%) agreed that it is within the scope of dental practice to help smokers quit. The most important barriers to providing cessation services included perceived patient resistance (44%) and lack of a supportive organisation (36%). This was the first assessment of approaches to tobacco users by dental students in Iran. Although there clearly is room for improvement, the interest of the students toward tobacco cessation is encouraging.