The effect of varying healing times on orthodontic mini-implant stability: a microscopic computerized tomographic and biomechanical analysis.
ABSTRACT The aim of this study was to evaluate the effect of different healing times on the stability of titanium mini-implants used for orthodontic anchorage.
Eight male beagles were used and randomized into 4 groups according to different healing times (1, 3, 5, and 7 weeks); each group had 2 beagles. Sixty-four mini-implants were inserted bilaterally in the maxilla and mandible of the beagles. Microscopic computerized tomography (μCT) and pull-out test were used for morphometric and biomechanical analysis, respectively.
All μCT parameters and F(max) (maximum pull-out force) increased with the prolongation of healing time. One week after insertion, all 4 measurements, namely osseointegration, trabecular bone volume density, intersection surface, and F(max), were lower in the maxilla group than in the mandible group (P < .05). Between the span of 1 and 3 weeks after insertion, a more obvious rising tendency of the 4 values was observed in the maxilla group than in the mandible group. Five and 7 weeks after insertion, the maxilla group expressed higher values of the 4 measurements than the mandible group (P < .05).
Although insertion in the mandible could provide higher primary stability for mini-implants, with the prolongation of healing time, insertion in the maxilla achieves higher osseointegration. The results indicated that insertion in maxilla has a more positive effect on the stability of mini-implants than insertion in the mandible.
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ABSTRACT: It has been suggested that the quality of clinical trials should be assessed by blinded raters to limit the risk of introducing bias into meta-analyses and systematic reviews, and into the peer-review process. There is very little evidence in the literature to substantiate this. This study describes the development of an instrument to assess the quality of reports of randomized clinical trials (RCTs) in pain research and its use to determine the effect of rater blinding on the assessments of quality. A multidisciplinary panel of six judges produced an initial version of the instrument. Fourteen raters from three different backgrounds assessed the quality of 36 research reports in pain research, selected from three different samples. Seven were allocated randomly to perform the assessments under blind conditions. The final version of the instrument included three items. These items were scored consistently by all the raters regardless of background and could discriminate between reports from the different samples. Blind assessments produced significantly lower and more consistent scores than open assessments. The implications of this finding for systematic reviews, meta-analytic research and the peer-review process are discussed.Controlled Clinical Trials 03/1996; 17(1):1-12.
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ABSTRACT: Large discrepancies in the available data on skin microbiology stimulated investigations of the number, interactions, and location of commensals and the true efficiency of disinfection by using skin biopsy, culture of frozen sections, and other methods.Most current procedures were less than 0.5% as sensitive as the biopsy method described. This gave mean bacterial counts ranging from 4,400/cm(2) on the breast to 400,000/cm(2) in the axillae. An iodine preparation removed 95% of accessible organisms, but about 20% of bacteria were protected by follicles, crevices, and lipids. Commensals in over 20% of people produced antibiotics against a wide range of pathogens. Conversely, "satellitism" was demonstrable in 12% of people.British medical journal 02/1972; 1(5793):136-40.
- Journal of Clinical Microbiology 07/2003; 41(6):2275-8. · 4.07 Impact Factor