Effects of genetic variants of CCR5 chemokine receptors on oral squamous cell carcinoma.

We aimed to evaluate the effect of genetic variants of the chemokine C-C motif receptor (CCR5) in the pathogenesis of oral squamous cell carcinoma (OSCC). A total of 127 patients diagnosed with OSCC and 104 healthy individuals were included in the study. The polymorphisms CCR5 59029 and CCR5-delta32 were assessed with the polymerase chain reaction-restricted fragment length polymorphism (PCR-RFLP) method from peripheral blood samples of both groups. There was a statistically significant difference between the control and patient groups for CCR5 59029 A/G genotypes (P < 0.01). Individuals carrying the CCR5 59029 G allele (GG +AG genotypes) had a 2.84-fold increased risk for OSCC (P < 0.0001), and the CCR5 59029 AA genotype frequency was higher in the control group than in the patient group (P < 0.0001). The CCR5-delta 32 genotype frequencies did not differ significantly between controls and cases (P > 0.05). CCR5 59029 GG and CCR5-delta32 DD + ID genotype frequencies were significantly increased in Grade II-III OSCC patients compared with Grade I-II OSCC patients. In conclusion, these results suggested that the G allele of the CCR5 59029 polymorphism might be a risk factor due to the loss of receptor function that might cause increased inflammation leading to the development of OSCC.

A comparative analysis of the accuracy of different direct impression techniques for multiple implants.

BACKGROUND: The aim of this study was to compare the accuracy of different direct implant impression techniques for edentulous arches with multiple implants. METHODS: Five experimental groups (n = 5) were assembled. Experimental models were created by a direct splinted technique (EG2 to EG5) and a non-splinted technique (EG1). In EG2 and EG3 synOcta impression copings were splinted with an acrylic resin bar, and in EG4 and EG5 with a light-curing composite resin bar. In EG3 and EG5 the resin bars were sectioned, while the other experimental groups were not. Three-dimensional discrepancies were measured by a computerized coordinate measuring machine. Distortion values among the groups were analysed using one-way repeated measures ANOVA. The post hoc Tukey's test was then performed for multiple comparisons. RESULTS: The highest accuracy was obtained in EG2 (mean deviation: 12.70 µm). The acrylic bars demonstrated less deviation (12.70 µm and 22.71 µm) from the master model than the light-curing composite resin groups and the non-splinted group (41.09 µm). The post hoc Tukey's test showed no significant difference among the groups when the effect of splint design on accuracy was investigated. CONCLUSIONS: For situations where impressions of multiple implants are to be made, splinting impression copings with acrylic resin demonstrate superior results than the non-splinted technique and splinting with light-curing composite.

Clinical evaluation of small diameter straumann implants in partially edentulous patients: a 5-year retrospective study.

OBJECTIVE: The aim of the present study was to retrospectively evaluate small-diameter (3.3 mm) Straumann® dental implants placed in the maxilla or the mandible over a period of 5 years in function. MATERIALS AND METHODS: Twenty-eight partially edentulous patients received a total of 48 implants over a 5-year period. After the standard healing period (3 to 6 months), the implants were restored with single-tooth prostheses or fixed partial dentures. All patients were followed according to a strict maintenance program with regular recalls. The cumulative survival rates of implants were analyzed and prosthetic complications were assessed. RESULTS: After 5 years of function, one single 10-mm-long implant in the maxillary premolar region was lost because of recurrent peri-implant infection in a female patient. Two single 10-mm-long maxillary implants placed in the posterior region were lost due to body fracture. The cumulative 5-year survival rate of the implants was 93.75 %. The most common prosthetic complication was loosening of the occlusal screw. CONCLUSION: Within the limited observation period and the number of patients included in this study, it may be concluded that the use of small-diameter implants appears to be predictable if clinical guidelines are followed and appropriate prosthetic restorations are provided. However, it should be noted that fatigue fracture may occur.