In vitro evaluation of various bioabsorbable and nonresorbable barrier membranes for guided tissue regeneration

<p>Abstract</p> <p>Background</p> <p>Different types of bioabsorbable and nonresorbable membranes have been widely used for guided tissue regeneration (GTR) with its ultimate goal of regenerating lost periodontal structures. The purpose of the present study was to evaluate the biological effects of various bioabsorbable and nonresorbable membranes in cultures of primary human gingival fibroblasts (HGF), periodontal ligament fibroblasts (PDLF) and human osteoblast-like (HOB) cells <it>in vitro</it>.</p> <p>Methods</p> <p>Three commercially available collagen membranes [TutoDent^®(TD), Resodont^®(RD) and BioGide^®(BG)] as well as three nonresorbable polytetrafluoroethylene (PTFE) membranes [ACE (AC), Cytoplast^®(CT) and TefGen-FD^®(TG)] were tested. Cells plated on culture dishes (CD) served as positive controls. The effect of the barrier membranes on HGF, PDLF as well as HOB cells was assessed by the Alamar Blue fluorometric proliferation assay after 1, 2.5, 4, 24 and 48 h time periods. The structural and morphological properties of the membranes were evaluated by scanning electron microscopy (SEM).</p> <p>Results</p> <p>The results showed that of the six barriers tested, TD and RD demonstrated the highest rate of HGF proliferation at both earlier (1 h) and later (48 h) time periods (<it>P </it>< 0.001) compared to all other tested barriers and CD. Similarly, TD, RD and BG had significantly higher numbers of cells at all time periods when compared with the positive control in PDLF culture (<it>P </it>≤ 0.001). In HOB cell culture, the highest rate of cell proliferation was also calculated for TD at all time periods (<it>P </it>< 0.001). SEM observations demonstrated a microporous structure of all collagen membranes, with a compact top surface and a porous bottom surface, whereas the nonresorbable PTFE membranes demonstrated a homogenous structure with a symmetric dense skin layer.</p> <p>Conclusion</p> <p>Results from the present study suggested that GTR membrane materials, per se, may influence cell proliferation in the process of periodontal tissue/bone regeneration. Among the six membranes examined, the bioabsorbable membranes demonstrated to be more suitable to stimulate cellular proliferation compared to nonresorbable PTFE membranes.</p

An overview of periodontal regenerative procedures for the general dental practitioner.

The complete regeneration of the periodontal tissues following periodontal disease remains an unmet challenge, and has presented clinicians with a remarkably difficult clinical challenge to solve given the extensive research in this area and our current understanding of the biology of the periodontal tissues. In particular as clinicians we look for treatments that will improve the predictability of the procedure, improve the magnitude of the effect of treatment, and perhaps most importantly in the long term would extend the indications for treatment beyond the need for single enclosed bony defects to allow for suprabony regeneration, preferably with beneficial effects on the gingival soft tissues. A rapid development in both innovative methods and products for the correction of periodontal deficiencies have been reported during the last three decades. For example, guided tissue regeneration with or without the use of bone supplements has been a well-proven treatment modality for the reconstruction of bony defects prior to the tissue engineering era. Active biomaterials have been subsequently introduced to the periodontal community with supporting dental literature suggesting that certain factors should be taken into consideration when undertaking periodontal regenerative procedures. These factors as well as a number of other translational research issues will need to be addressed, and ultimately it is vital that we do not extrapolate results from pre-clinical and animal studies without conducting extensive randomized clinical trials to substantiate outcomes from these procedures. Whatever the outcomes, the pursuit of regeneration of the periodontal tissues remains a goal worth pursuing for our patients. The aim of the review, therefore is to update clinicians on the recent advances in both materials and techniques in periodontal regenerative procedures and to highlight the importance of both patient factors and the technical aspects of regenerative procedures

Modulation of clinical expression of plaque-induced gingivitis. I. Background review and rationale.

OBJECTIVES: The purpose of this article is to provide the necessary background and rationale for the accompanying studies, which are ultimately aimed at identifying genetic and environmental factors determining gingivitis susceptibility. MATERIALS AND METHODS: The literature on factors reported to modify the clinical expression of gingivitis, i.e., factors that determine individual variability in gingival inflammatory response to plaque, is presented. RESULTS: Clinical evidence suggests that the gingival inflammatory response to plaque accumulation may differ substantially among individuals. However, most of the available studies are of small scale and not purposely designed to address the issue. Systemic factors implicated in modulation of the clinical expression of gingivitis include metabolic, genetic, environmental and other factors. The significance of such factors in designing and conducting a large-scale experimental gingivitis trial and means to account for them are discussed. CONCLUSION: Although several factors have been implicated, genetic or environmental factors underlying differences in gingivitis expression are not fully elucidated. The accompanying studies aim to identify and characterize, among participants in a specifically designed large-scale experimental gingivitis trial, subjects that differ significantly in their gingival inflammatory response to plaque. This is the first step in an effort to determine genetic or environmental factors underlying such differences

Adverse effects associated with the use of an absorbable GTR device in the treatment of human gingival recession defects. A clinicopathologic case report.

This clinicopathologic case report documents an adverse effect associated with the use of a polylactic acid-based barrier in the treatment of human gingival recession defects. A total of 27 consecutively treated patients, in whom guided tissue regeneration with a polylactic acid barrier was used to correct gingival recession defects, were evaluated. This adverse effect consisted of a midradicular-apical swelling, generally asymptomatic, with no apparent predilection for gender, age, tooth type or location (maxilla/mandible), or surgical procedure. It was observed in 14 of 27 (52%) patients and 22 of 41 (54%) defects. The swelling decreased in size over time and in most cases, it completely resolved within 12 months postsurgery. Histopathologic evaluation of a 14-week specimen indicated characteristics (multinucleated giant cells, foamy macrophages) consistent with a foreign body reaction. These findings suggest that patients undergoing GTR procedures with synthetic absorbable devices for the treatment of gingival recession defects should be advised of the possible occurrence of such an adverse effect

Renal outcomes associated with glucose-lowering agents: Systematic review and meta-analysis of randomized outcome trials

Although the clinical questions of the recent glucose-lowering trials are principally oriented towards preventing macrovascular events, an updated review regarding renal outcome prevention is lacking. We assessed the impact of different antihyperglycemic classes on kidney damage progression. A systematic review and meta-analysis was performed by searching PubMed, Cochrane Collaboration Library, Medline, and previous overviews through June 2021 (any language) for earlier and contemporary glucose-lowering trials, including patients with, but not limited to, type 2 diabetes mellitus vs. placebo or less intense treatment. Incidences of kidney function worsening and macroalbuminuria development was extracted, and risk ratios and 95% confidence intervals (CI) under the random-effects model were calculated. The association between outcome reductions and glycohemoglobin (HBA1c) reductions was investigated through the meta-regression analyses. Among 27 eligible trials (n = 198,532 patients) an averaged HBA1c reduction of 0.6 ± 0.3% was followed by a reduction of 17% (95% CI, 8–25%) in worsening of kidney function, and of 25% (95% CI, 19–32%) in macroalbuminuria. Analog of human glucagon-like peptide 1 (GLP1)-agonists, and sodium-glucose cotransporter (SGLT2)-inhibitors, considered separately, compared with placebo, were associated with a significant reduction of both renal outcomes, at variance with dipeptidyl peptidase 4 (DPP4)-inhibitors, where no outcome change was observed. Logarithmic risk ratios of macroalbuminuria were related to HBA1c reductions, in contrast to the worsening of kidney function related to systolic blood pressure reduction. Worsening of kidney function and macroalbuminuria development were reduced following glucose-lowering. GLP1 agonists and SGLPT2 inhibitors were associated with protection against both outcomes, while DPP4 inhibitors do not provide renal protection. © 2021 European Federation of Internal Medicin

Wearable blood pressure measurement devices and new approaches in hypertension management: the digital era

Out-of-office blood pressure (BP) measurement is considered an integral component of the diagnostic algorithm and management of hypertension. In the era of digitalization, a great deal of wearable BP measuring devices has been developed. These digital blood pressure monitors allow frequent BP measurements with minimal annoyance to the patient while they do promise radical changes regarding the diagnostic accuracy, as the importance of making an accurate diagnosis of hypertension has become evident. By increasing the number of BP measurements in different conditions, these monitors allow accurate identification of different clinical phenotypes, such as masked hypertension and pathological BP variability, that seem to have a negative impact on cardiovascular prognosis. Frequent measurements of BP and the incorporation of new features in BP variability, both enable well-rounded interpretation of BP data in the context of real-life settings. This article is a review of all different technologies and wearable BP monitoring devices. © 2022, The Author(s), under exclusive licence to Springer Nature Limited

Using Multimedia/Hypermedia Tools over Networks for Distance Education and Training

The rapid developments in the Information Technology sector as well as the deployment of faster networks brings us to the era of the New Information Technology (NIT). The citizen of the near future must be able to use them else he will be seriously handicapped in his everyday life. Thus NIT becomes part of the educational process while on the other hand offers the tools and the infrastructure for the establishment of the distance education process. The educators are one of the first professions that must learn to use NIT and its tools. Multimedia/hypermedia tools offer solutions to the problems posed by the distance education process. They can be user-friendly and enticing and they can cover most, if not all, the needs of their users. A lot of prototype systems (tools) for distance education have been developed, each offering a number of functions that aid the process of distance education. The rapid growth of World Wide Web is adding another factor that can lead to the wider deployment of distance education systems. Although the value of distance education is unquestionable there is still a lot of work to be done before a wide spread implementation platform emerges