Urine products of bone breakdown as markers of bone resorption and clinical usefulness of urinary hydroxyproline: an overview / 中华医学杂志(英文版)

<p><b>PURPOSE</b>The purpose of this study is to review the urine products of bone breakdown as markers of bone resorption and usefulness of urinary hydroxyproline.</p><p><b>DATA</b>Related researches published in 1985 - 2000 were systematically reviewed.</p><p><b>RESULTS</b>Bone markers could be used for early diagnosis of bone metabolic diseases. Biochemical markers of bone resorption that reflect osteoclast activity and/or collagen degradation provide a new and potentially important clinical tool for the assessment and monitoring of bone metabolism. Assessment of bone resorption can be achieved with measurement of urinary hydroxylysine glycosides, urinary excretion of the collagen pyridinium cross-links, urinary excretion of type I collagen telopeptide breakdown products (cross-linked telopeptides) and urinary hydroxyproline.</p><p><b>CONCLUSION</b>Urinary hydroxyproline has been in use as a marker of bone resorption, but it lacks sensitivity and specificity. It is a modified amino acid that is a metabolic product of collagen breakdown. Hydroxyproline may be released either free or with fragments of the collagen molecule attached during bone resorption, and it is also liberated by the breakdown of complement and nonskeletal collagen.</p>

Evaluation of success rates of immediate and delayed implants after tooth extraction / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To evaluate the success rates of immediate and delayed placement of implants with respect to the causes of tooth extraction and implant positions.</p><p><b>METHODS</b>A total of 310 dental implants (immediate implants:delayed implants = 76:234) were inserted into 80 patients. The types, sizes and positions of the implants and the causes of tooth extraction were recorded. We then investigated the relationship of implant loss with the causes of tooth extraction and placement methods.</p><p><b>RESULTS</b>A higher failure rate was found for the implants in the posterior region of the maxilla, and when periodontitis was cited as a reason for tooth extraction. The overall success rates were 93.4% and 95.7% in the immediate and delayed implant placement groups, respectively, after a 2-year follow-up. No obvious relationship of success rate was observed with the implant placement method, cause of tooth extraction, and implants' position.</p><p><b>CONCLUSION</b>The immediate placement of implants into fresh extraction sockets could offer advantages over the delayed implant placement. It seems to be a safe and predictable method for patients.</p>