Assessment of the effect of laser irradiations at different wavelengths (660, 810, 980, and 1064 nm) on autophagy in a rat model of mucositis.

It is known that high-dose radiation has an effect on tissue healing, but tissue healing does not occur when low dose radiation is applied. To clarify this issue, we compare the treatment success of low dose radiation with programmed cell death mechanisms on wounded tissue. In this study, we aimed to investigate the interactions of low and high-dose radiation using an autophagic mechanism. We included 35 adult Wistar-Albino rats in this study. All animals were injected with 100 mg/kg of 5-fluorouracil (5-FU) on the first day and 65 mg/kg of 5-FU on the third day. The tips of 18-gauge needles were used to develop a superficial scratching on the left cheek pouch mucosa by dragging in a linear movement on third and fifth days. After mucositis formation was clinically detected, animals were divided into five groups (n = 7). Different wavelengths of laser irradiations (1064 nm, Fidelis Plus, Fotona, Slovenia; 980 nm, FOX laser, A.R.C., Germany; 810 nm, Fotona XD, Fotona, Slovenia; 660 nm, HELBO, Medizintechnik GmbH, Wels, Austria) were performed on four groups once daily for 4 days. The laser irradiation was not performed on the control group. To get the tissue from the left cheek at the end of fourth day from all animals, oval excisional biopsy was performed. Molecular analysis assessments of pathological and normal tissue taken were performed. For this purpose, the expression analysis of autophagy genes was performed. The results were evaluated by normalization and statistics analysis. We found that Ulk1, Beclin1, and Atg5 expression levels were increased in the rats when the Nd:YAG laser was applied. This increase showed that a 1064-nm laser is needed to activate the autophagic mechanism. However, in the diode applications, we found that Beclin1, Atg10, Atg5, and Atg7 expressions numerically decreased. Atg5 is responsible for the elongation of autophagosome. Becn1 is a control gene in the control mechanism of autophagy. The reduction of the expression of these genes leads us to think that it may depend on the effect of drug (5-FU) used to form model. Expressions of therapeutic genes increase to ensure hemostasis, but in our study, expressions were found to decrease. More detailed studies are needed.

Musculoskeletal complaints among oral and maxillofacial surgeons and dentists: a questionnaire study.

OBJECTIVE: This is a questionnaire study aimed to collect information from Turkish dentists and oral and maxillofacial surgeons concerning common occupation-related health problems, their knowledge about these problems and the precautions they commonly took. STUDY DESIGN: This study involved a postal questionnaire survey of oral and maxillofacial surgeons and other dentists working in various regions of Turkey in both public and private dental institutions in 2010. RESULTS: A total of 608 dentists (337 female, 271 male) were included in the study group and evaluated for musculoskeletal complaints. The mean age of participant was 27.63 ± 9.5, ranging from 22-63 years old. Working position is very important for development of pain. This study exhibited that a significant proportion of dentists with pain worked in standing or sitting alternately working positions (p < 0.001). This study found that 39% of dentists worked in standing position with loading on the right foot, 14.6% loading on left foot and 46.4% loading on both the right and left foot alternately to balance their body weights. It was found that 57% of respondents had worked with a dental assistant and 43% had not. CONCLUSION: In this study, it was found that musculoskeletal complaints were most frequently seen at dentists and oral and maxillofacial surgeons who have long working hours per day, working in sitting or standing positions alternately and intermittent working designs.

Shear bond strength of indirect composite material to monolithic zirconia.

PURPOSE: This study aimed to evaluate the effect of surface treatments on bond strength of indirect composite material (Tescera Indirect Composite System) to monolithic zirconia (inCoris TZI). MATERIALS AND METHODS: Partially stabilized monolithic zirconia blocks were cut into with 2.0 mm thickness. Sintered zirconia specimens were divided into different surface treatment groups: no treatment (control), sandblasting, glaze layer & hydrofluoric acid application, and sandblasting + glaze layer & hydrofluoric acid application. The indirect composite material was applied to the surface of the monolithic zirconia specimens. Shear bond strength value of each specimen was evaluated after thermocycling. The fractured surface of each specimen was examined with a stereomicroscope and a scanning electron microscope to assess the failure types. The data were analyzed using one-way analysis of variance (ANOVA) and Tukey LSD tests (α=.05). RESULTS: Bond strength was significantly lower in untreated specimens than in sandblasted specimens (P<.05). No difference between the glaze layer and hydrofluoric acid application treated groups were observed. However, bond strength for these groups were significantly higher as compared with the other two groups (P<.05). CONCLUSION: Combined use of glaze layer & hydrofluoric acid application and silanization are reliable for strong and durable bonding between indirect composite material and monolithic zirconia.

Antimicrobial efficiency of photodynamic therapy with different irradiation durations.

OBJECTIVE: This study aimed to evaluate the antimicrobial efficiency of PDT and the effect of different irradiation durations on the antimicrobial efficiency of PDT. MATERIALS AND METHODS: Sixty freshly extracted human teeth with a single root were decoronated and distributed into five groups. The control group received no treatment. Group 1 was treated with a 5% sodium hypochlorite (NaOCl) solution. Groups 2, 3, and 4 were treated with methylene-blue photosensitizer and 660-nm diode laser irradiation for 1, 2, and 4 min, respectively. The root canals were instrumented and irrigated with NaOCl, ethylenediamine-tetraacetic acid, and a saline solution, followed by autoclaving. All the roots were inoculated with an Enterococcus faecalis suspension and brain heart infusion broth and stored for 21 days to allow biofilm formation. Microbiological data on microorganism load were collected before and after the disinfection procedures and analyzed with the Wilcoxon ranged test, the Kruskal-Wallis test, and the Dunn's test. RESULTS: The microorganism load in the control group increased. The lowest reduction in the microorganism load was observed in the 1-min irradiation group (Group 2 = 99.8%), which was very close to the results of the other experimental groups (99.9%). There were no significant differences among the groups. CONCLUSIONS: PDT is as effective as conventional 5% NaOCl irrigation with regard to antimicrobial efficiency against Enterococcus faecalis.

Conservative approach for restoring posterior missing tooth with fiber reinforcement materials: four clinical reports.

Adhesively luted, fiber-reinforced, composite-inlay, retained fixed-partial dentures can be a clinical alternative for the replacement of missing posterior teeth in selective situations. This type of restoration allows for satisfactory esthetics and reduced tooth preparation compared to a conventional, fixed-partial denture. This clinical report describes the use of a fiber-reinforced, composite-inlay, retained fixed-partial denture as a conservative alternative for the replacement of missing posterior teeth.