statement of problem: thermal injury during dental implant placement and restoration is a clinical concern as it may cause bone damage and compromise osseointegration. the threshold level for heat-induced cortical bone necrosis is 47°c for 60 seconds. objectives: to measure the amount of heat transferred to the implant-bone interface when a two-piece or one-piece abutment was prepared in vertic...

BACKGROUND Central to the design of a randomised controlled trial is the calculation of the number of participants needed. This is typically achieved by specifying a target difference and calculating the corresponding sample size, which provides reassurance that the trial will have the required statistical power (at the planned statistical significance level) to identify whether a difference of...

A sample size calculation for logistic regression involves complicated formulae. This paper suggests use of sample size formulae for comparing means or for comparing proportions in order to calculate the required sample size for a simple logistic regression model. One can then adjust the required sample size for a multiple logistic regression model by a variance inflation factor. This method re...

Exact power and sample size calculation for bioequivalence studies with high order crossover designs using statistical software nQuery are presented. Such calculation can be very easily performed, and thus provides a convenient tool for practical usage.

Several pathological condit ions i n which bone mineral izat ion i s deficient have been observed. These can a r i s e from a number of conditions including abnormali t ies i n hormonal regulat ion, r e n a l cor t ical damage and lack of adequa te calcium and vitamin D in the die t . Osteoporosis, t he most common condition, i s associated with aging in both sexes and with alterations in hormo...

This book is intended for biologists, medical physicists, biomechanical engineers and clinicians who are involved in bone studies. For these practitioners, the book is a comprehensive review of physical measurement techniques applied to bone, with useful emphasis on practical aspects such as protocols of measurement, sample preparation and sources of errors. Chapters were written by leading sci...

In clinical research, parameters required for sample size calculation are usually unknown. A typical approach is to use estimates from some pilot studies as the true parameters in the calculation. This approach, however, does not take into consideration sampling error. Thus, the resulting sample size could be misleading if the sampling error is substantial. As an alternative, we suggest a Bayes...

The aim of the present study was to analyze the osteogenic potential of a biphasic calcium composite material (BCC) with a negative surface charge for maxillary sinus floor augmentation. In a 61 year old patient, the BCC material was used in a bilateral sinus floor augmentation procedure. Six months postoperative, a bone sample was taken from the augmented regions before two titanium implants w...

Introduction: Alendronate, a second generation bisphosphonate, is known to increase bone density by inhibiting osteoclastic bone resorption. It is clincally used to treat osteoporosis, Paget’s disease and hypercalcemia associated with malignancy [1]. In clinical trials and animal studies, the effects are typically quantified by measuring bone mineral density. In this study, we sought to determi...