Association of MDR1 C3435T and C1236T single nucleotide polymorphisms with male factor infertility.

Infertility affects 1 in 6 couples and approximately 1 in 25 men. Male factor infertility is a major cause of spermatogenic anomalies, the causes of which are largely unknown. Impaired repro-ductive functions in men might result from physiological, genetic, and/or environmental factors such as xenobiotics. The multi-drug re-sistance1 (MDR1) gene encodes a P-glycoprotein which has a role in the active transport of various substrates providing protection of somatic cells from potentially toxic substances, including xenobi-otics. MDR1 is highly expressed at the luminal surface of capillary endothelial cells, and is expressed in Leydig cells, testicular mac-rophages, and Sertoli cells. We performed genotype and haplotype analyses of MDR1 in 192 infertile and 102 fertile Turkish men for the genetic markers C1236T and C3435T, using polymerase chain reaction-restriction fragment length polymorphism analysis. In the overall population, correlations were analyzed in all genotype mod-els. We found that the C3435T polymorphism TT vs CT genotypes showed statistically significant differences in their association with infertility (P = 0.045), and that the CT genotype was associated with high sperm DNA damage (P = 0.02), suggesting that the CT genotype might be a susceptibility factor for infertility. Additionally, the T-T haplotype was significantly more frequent in the control group (13.2 vs 6.5%; odds ratio = 0.459, 95%CI = 0.259-0.814, P = 0.006). This study showed that MDR1 might have a role in male infertility. Fur-ther research in large cohorts with different populations is required to clarify the role of MDR in male fertility.

The effect of casein phosphopeptide-amorphous calcium phosphate on enamel surface rehardening. An in vitro study.

AIM: Casein phosphopeptide stabilised amorphous calcium phosphate (CPP-ACP) has been shown to remineralise enamel subsurface lesions. The aim of this study was to determine the effect of a paste containing 10% CPP-ACP (Toothmousse; GC) on enamel surface microhardness in vitro. MATERIALS AND METHODS: Thirty enamel blocks (3x2 mm) were prepared for the study group from the buccal surface of extracted teeth. The microhardness of the enamel surface was determined for the specimens initially before artificial demineralisation. After demineralization the specimens were incubated in 10% CPP-ACP for 5 min. Artificial saliva was used as a remineralising solution for the control group. RESULTS: The mean baseline surface microhardness analyses of enamel blocks were 318.61±25.75 and 262.49±26.82. The data show that after demineralisation the mean microhardness decline in the experimental groups (247.05± 38.31 and 186.92± 63.77). The results showed that 10% CPP-ACP (281.79±26.32) was comparable to the control (252.27± 31.05) for remineralisation of enamel subsurface lesions in vitro. The highest surface microhardness recovery (%SMHR) was found for control, but the differences of % SMHR between 10% CPP-ACP and control was not statistically significant (p=0.805). CONCLUSION: From the results it can be concluded that CPP-ACP may have positive effects on enamel remineralisation.

The effect of low level laser therapy on pain during dental tooth-cavity preparation in children.

AIM: To evaluate the effect of low level laser therapy on pain during cavity preparation with laser in paediatric dental patients. STUDY DESIGN AND METHODS: The study was carried out on 10 children aged 6 to 9 years old for a total of 20 primary molar teeth. For laser preparation an Er: YAG laser was used. Half of the preparations were treated by low level laser therapy (LLLT) before laser preparation and the remaining half without LLLT (non-LLLT) before laser preparation. All cavities were prepared by ER:YAG laser, restored with light-cured composite resin following the application of acid etching and bonding agent. Children were instructed to rate their pain on the visual analogue scale (VAS) from 0 to 5 points. Statistical analyses were performed using Mann Whitney U test. RESULTS: VAS Median (min-max) scores were 1(0-2) for LLLT and 3(1-4) for the non-LLT treated children. Between LLLT and non- LLLT groups results were statistically significant (p<0.01). CONCLUSIONS: The use of LLLT before cavity preparation with laser decreased pain in paediatric dental patients.

The effect of laser-activated Acidulated Phosphate Fluoride on enamel submitted to erosive solution only: an in vitro preliminary evaluation.

AIM: The purpose of this in vitro study was to evaluate the potential effect of laser therapy on the prevention of erosive demineralisation either alone or combined with acidulated phosphate fluoride gel on human enamel. It was hypothesized that such a treatment would decrease enamel solubility. STUDY DESIGN: Efficacy of 2940 nm Er:YAG laser with preset parameters--alone or combined with APF (Acidulated Phosphate Fluoride) gel--was tested on freshly extracted human permanent molars. MATERIALS AND METHODS: Ten sound human third molars were sectioned into 5 surfaces (2 x 3 mm) with hard tissue microtome and were randomly allocated into different treatment groups as follows. The Vicker's hardness of each surface was obtained at the baseline. Group 1, negative control group: no treatment. Group 2, positive control group: only 1.23% APF gel (Denti-Care gel, Medicom) 1 minute application. Group 3: irradiated with surface modification mode (2940 nm, 1.2j/cm², 10 Hz, 300 µm) Er:YAG laser. Group 4: Er:YAG laser application following 1.23% APF gel. Group 5: 1.23% APF gel following Er:YAG laser application. The demineralisation process was obtained by immersion of specimens in a soft drink for 10 minutes and then the Vickers hardness was reevaluated. STATISTICS: For statistical analyses within groups the Kruskal Wallis test was used, while for comparing groups the paired sample t test (significance p<0.05) was used. RESULTS: The difference in microhardness values of each group obtained following the treatments was not statistically significant (p>0.05). Beside, no statistical difference was found in Vickers value related to the application of fluoride prior or after laser therapy. Conclusion Er:YAG laser irradiation alone or combined with APF decreased the enamel solubility but combined treatment did not show any significant additional effect.

Conventional endodontic treatment of primary molars using metronidazole as an intra-canal medicament: a pilot study.

AIM: This was to evaluate the clinical and radiographic outcomes of an antibacterial drug (Metronidazole, Nidazol, IE Ulagay Ilac A.S) application as an intra-canal medicament combined with pulpectomy in infected primary molar teeth. METHODS: The study material consisted of data collected from children treated at the Dental School Dept. of Paediatric Dentistry in Marmara University between 2000 and 2004. Clinical and radiographic data were collected over 2 years from patients who had received a topical application of metronidazole in root canal dressing before a pulpectomy was completed. Clinical success parameters were: no abscess formation, no fistula, no pain and no pathologic mobility at treated teeth with metranidazole dressing. The overall success and failure rates were analysed. Radiographic diagnosis was standardized between investigators and intra and inter-rater reliability assessed. Both investigators read and evaluated all radiographs, after a comparison of results, a consensus was agreed upon for each result. STATISTICS: All data were entered into an Excel format and SPSS 11.0 P < 0.05 were used for Windows and Chi-square for statistical analyses. RESULTS: There were 64 molars assessed for clinical and radiographic success. Considering the eruption times, success rate was 75% as determined by the last follow up clinically and radiographically according to predetermined success criteria. In the 64 molars, 4 cases demonstrated loss of the alveolar bone, 3 exhibited varying degrees of root resorptions on radiographic examination and 3 showed clinical pathologic mobility. Fistulae were observed in only 1 case and early loss was detected in 5 cases. CONCLUSION: These results suggest that main factors responsible for failure may be associated with uncertain mixing proportions of the metronidazole paste and inadequate maxillary restorations. But some modifications in preparing the paste could increase its efficacy.