Biomedical subjects

A M Polson

Publications and source records attributed to A M Polson.

At least 19 recordsLinked to original sources

PubMed2001

Subantimicrobial dose doxycycline as an adjunct to scaling and root planing: post-treatment effects.

BACKGROUND/OBJECTIVE: Subantimicrobial dose doxycycline (SDD 20 mg bid) plus scaling and root planing (SRP) significantly improved clinical attachment level (CAL) and reduced probing depth (PD) compared with placebo plus SRP in a double-blind, placebo-controlled, multicenter study of patients with adult periodontitis (AP). In a study conducted as a follow-up, the post-treatment effects of SDD were assessed in patients who completed the SRP study. METHODS: The SRP study was a 9-month, active-treatment study and the follow-up was a 3-month, no-treatment study. In the SRP study, tooth sites in qualifying quadrants were scaled and root planed and patients were randomized to receive twice daily SDD 20 mg or placebo. In the follow-up, patients received no study drug; investigators and patients remained blinded to the previous treatment group assignments. Efficacy measures included the change in CAL and PD from baseline values determined at the start of the SRP study in tooth sites stratified by baseline PD (i.e., 0-3 mm, 4-6 mm, > or =7 mm). Safety was evaluated using adverse event data and the results of clinical laboratory tests, oral pathology examinations, and microbiological assessments. RESULTS: Within each disease stratum, the incremental improvements in PD and CAL demonstrated in the SDD group over 9 months of active treatment were maintained through 3 additional months of no treatment. Treatment cessation did not result in an accelerated regression of periodontal health. No differences in the incidence of adverse events (including those related to infection) or laboratory or microbiological parameters were noted between the SDD group and the placebo group. CONCLUSIONS: The administration of SDD 20 mg bid for a period of up to 9 months is not associated with rebound effects or delayed or negative after-effects for a 3-month period after cessation of therapy.

Adult↗

PubMed2001

An economic evaluation of a chlorhexidine chip for treating chronic periodontitis: the CHIP (chlorhexidine in periodontitis) study.

BACKGROUND: The authors previously suggested that an adjunctive, controlled-release chlorhexidine, or CHX, chip may reduce periodontal surgical needs at little additional cost. This article presents an economic analysis of the CHX chip in general dental practice. METHODS: In a one-year prospective clinical trial, 484 chronic periodontitis patients in 52 general practices across the United States were treated with either scaling and root planing, or SRP, plus any therapy prescribed by treating, unblinded dentists; or SRP plus other therapy as above but including the CHX chip. Economic data were collected from bills, case report forms and 12-month treatment recommendations from blinded periodontist evaluators. RESULTS: Total dental charges were higher for SRP + CHX chip patients vs. SRP patients when CHX chip costs were included (P = .027) but lower when CHX chip costs were excluded (P = .012). About one-half of the CHX chip acquisition cost was offset by savings in other charges. SRP + CHX chip patients were about 50 percent less likely to undergo surgical procedures than were SRP patients (P = .021). At the end of the trial, periodontist evaluators recommended similar additional procedures for both groups: SRP, about 46 percent; maintenance, about 37 percent; surgery, 56 percent for SRP alone and 63 percent for SRP + CHX chip. CONCLUSIONS: Adjunctive CHX chip use for general-practice patients with periodontitis increased costs but reduced surgeries over one year. At study's end, periodontists recommended similar additional surgical treatment for both groups. CLINICAL IMPLICATIONS: In general practice, routine use of the CHX chip suggests that costs will be partially offset by reduced surgery over at least one year.

Adult↗

PubMed2000

Treatment with subantimicrobial dose doxycycline improves the efficacy of scaling and root planing in patients with adult periodontitis.

BACKGROUND: In a previous study, subantimicrobial dose doxycycline (SDD) significantly improved clinical parameters associated with periodontal health in patients with adult periodontitis (AP) when used as an adjunct to a maintenance schedule of supragingival scaling and dental prophylaxis. In this double-blind, placebo-controlled, parallel-group, multicenter study, the efficacy and safety of SDD were evaluated in conjunction with scaling and root planing (SRP) in patients with AP. METHODS: Patients (n = 190) received SRP at the baseline visit and were randomized to receive either SDD 20 mg bid or placebo bid for 9 months. Efficacy parameters included the per-patient mean changes in clinical attachment level (CAL) and probing depth (PD) from baseline, the per-patient percentages of tooth sites with attachment loss (AL) > or = 2 mm and > or = 3 mm from baseline, and the per-patient percentage of tooth sites with bleeding on probing. Prior to analysis, tooth sites were stratified by the degree of disease severity evident at baseline RESULTS: In tooth sites with mild to moderate disease and severe disease (n = 183, intent-to-treat population), improvements in CAL and PD were significantly greater with adjunctive SDD than with adjunctive placebo at 3, 6, and 9 months (all P <0.05). In tooth sites with severe disease, the per-patient percentage of sites with AL > or = 2 mm from baseline to month 9 was significantly lower with adjunctive SDD than with adjunctive placebo (P<0.05). Improvements in clinical outcomes occurred without detrimental shifts in the normal periodontal flora or the acquisition of doxycycline resistance or multiantibiotic resistance. SDD was well tolerated, with a low incidence of discontinuations due to adverse events. CONCLUSIONS: The adjunctive use of SDD with SRP is more effective than SRP alone and may represent a new approach in the long-term management of AP.

Adult↗

PubMed1999

In situ localization and characterization of active proteases in chronically inflamed and healthy human gingival tissues.

BACKGROUND: Studies have indicated an important role for host-derived proteases in the pathogenesis of periodontal disease. The objectives of this study were: 1) to develop an assay measuring protease activity in situ and 2) to localize and characterize the enzymatic activity in intact inflamed and healthy gingiva. METHODS: Gingival specimens were prepared and over-laid with a quenched fluorescent substrate. Protease activity was visualized by fluorescence microscopy and correlated with histologic features. RESULTS: In inflamed tissues, enzymatic activity was detected mainly in the connective tissue (predominantly matrix metalloproteases) and, to some extent, in the epithelium (predominantly serine proteases). In contrast, clinically healthy tissues failed to exhibit significant amounts of protease activity. Quantitative and qualitative characteristics of protease activity in intact tissues were found to be pH dependent. CONCLUSIONS: The method described here enabled assessment of active proteases in intact tissues where cell-cell and cell-matrix interactions had been maintained. Our results indicate that there are substantial differences in the distribution of specific proteases between clinically healthy and inflamed periodontal tissues.

Adult↗

PubMed1998

Biodegradation and biocompatibility of a guided tissue regeneration barrier membrane formed from a liquid polymer material.

Biodegradable barrier films were made by coagulating a solution of poly(DL-lactide) in N-methyl-2-pyrrolidone on porous polyethylene pads wetted with saline solution. The semisolid films were cut into 10 x 10 mm barriers and implanted subcutaneously in rabbits. At monthly intervals, the polymer implant sites were compared histologically to those implanted with USP negative control plastic. The polymer films were retrieved from the surrounding tissue, dried, weighed, and the changes in molecular weight determined using gel permeation chromatography. The molecular weight of the polymer decreased at a relatively constant rate over 5 months; however, no significant mass loss occurred until 5 months postimplantation. Also, no distinct histological differences were noted between the polymer barrier and the control plastic sites until 6 months when histiocytes and multinucleated giant cells showed a modest increase around fragmented polymer films. Similar barrier films also were fitted over naturally occurring buccal dehiscence defects in beagle dogs and the tissue sites compared histologically at 6 months to sham-operated control sites. New bone and dense connective tissues closely approximated segments of the remaining polymer and demonstrated the biocompatibility of the biodegradable films. Histomorphometric analyses of treated sites compared to sham controls showed that the polymer barrier is effective in promoting bone and cementum regeneration in periodontal defects in dogs.

Animals↗

PubMed1998

Controlled local delivery of antimicrobials in the treatment of periodontitis.

Five local delivery systems with five different antimicrobial agents have been discussed. All are capable of delivering high concentrations of their antimicrobial to the site of the periodontal infection. Although only one system, tetracycline fiber, is available in United States, two other systems, chlorhexidine chip and doxycycline polymer, may be available in the near future. Two other systems, metronidazole gel and minocycline ointment, are available in other countries. Data from pertinent studies were presented as were techniques for using the various systems. Indications for the use of the products were also discussed. In selecting the appropriate delivery system, the clinician has to weigh the efficacy of the products, ease of use, availability, and cost. Although local delivery systems do not replace existing periodontal therapies, they do have a place in the treatment of periodontitis and offer the dentist additional methods to aid in the control of periodontal diseases.

Anti-Bacterial Agents↗

PubMed1998

Dental implant outcomes in postmenopausal women undergoing hormone replacement.

To determine if hormone supplementation reduces the risk of failure for osseointegration of dental implants in postmenopausal women, the treatment outcomes of 116 women older than age 50, treated with 450 endosseous dental implants, were analyzed in this retrospective study. The findings indicated that hormone replacement therapy may not be linked with improved outcomes of endosseous dental implant treatment in postmenopausal women. Smoking, however, appears to significantly increase the implant failure rate in the group observed in this study.

Aged↗

PubMed1997

The research team, calibration, and quality assurance in clinical trials in periodontics.

The present report provides an overview of practical issues related to training, calibrating, and monitoring the individuals involved in conducting a clinical trial. These aspects are considered in relation to a theoretical multi-center clinical trial designed to test the safety and efficacy of a new periodontal treatment. Many factors need to be controlled in order to reduce inherent variability and provide standardization across the study population and study centers in a large-scale multi-center clinical trial. Components incorporated to control these factors include identification and recruitment of study centers, pre-study training and organization of the teams at the different research centers, quality assurance procedures and monitoring of the study for compliance with protocol and safety requirements, and management of databases. Details are given regarding the use of pre-study survey questionnaires to assess research center capabilities, methods for training and calibrating examiners and therapists and methods for integrating these aspects prior to actual study commencement, and quality assurance after the study has begun. The review considers the critical practical details regarding all of these aspects of study organization and execution.

Clinical Trials as Topic↗

PubMed1997

Multi-center comparative evaluation of subgingivally delivered sanguinarine and doxycycline in the treatment of periodontitis. I. Study design, procedures, and management.

The design and conduct of a 9-month multi-center clinical trial to evaluate the safety and efficacy of subgingivally delivered 5% sanguinarium chloride (SC) and 10% doxycycline hyclate (DH) from a biodegradable drug delivery system in the treatment of adult periodontitis is described. The 3-group randomized study of 180 adults with moderate to severe periodontitis was a modified double-blind parallel design. One group received DH, one group received SC, and the other group received the vehicle control (VC). Patients selected had two quadrants with a minimum of four periodontal pockets > or = 5 mm in depth with two sites > or = 7 mm. All qualifying sites exhibited bleeding on gentle probing. Qualifying sites were treated at baseline and again at 4 months. Clinical response was assessed by measuring attachment level, probing depth, and bleeding on probing at monthly examinations at qualifying sites and the entire dentition. The plaque index was measured monthly to verify oral hygiene status. The parallel design afforded the opportunity to distinguish between treatment effectiveness of SC, DH, and VC independent of possible crossover effects. Also the effectiveness of oral hygiene in untreated sites of the mouth could be evaluated. Finally, treatment effects in moderate (5 to 6 mm) and deep (> or = 7 mm) pockets in both treated and untreated sites could be compared. The design was capable of simulating a periodontal practice maintenance program and assessing the response according to maintenance and treatment history. Study management procedures that emphasized center examiner and therapist training and adherence to protocol and procedures to reduce variability are described.

Administration, Topical↗

PubMed1997

Multi-center comparative evaluation of subgingivally delivered sanguinarine and doxycycline in the treatment of periodontitis. II. Clinical results.

The clinical safety and effectiveness of a subgingivally delivered biodegradable drug delivery system containing either 10% doxycycline hyclate (DH), 5% sanguinarium chloride (SC) or no agent (VC) was evaluated in a 9-month multi-center trial. The study was a randomized parallel design with 180 patients who demonstrated moderate to severe periodontitis. All patients had at least two quadrants with a minimum of four qualifying pockets > or = 5 mm that bled on probing. Two of the qualifying pockets were required to be > or = 7 mm. At baseline and at 4 months all qualified sites were treated with the test article administered via syringe. Probing depth reduction (PDR), attachment level gain (ALG), bleeding on probing reduction (BOP), and plaque index were determined monthly. Analysis of efficacy data from the 173 efficacy-evaluable patients indicated that all treatments gave significant positive clinical changes from baseline at all subsequent timepoints. DH was superior to SC and VC in PDR at all timepoints (P < or = 0.01 to 0.001) with a maximum reduction of 2.0 mm at 5 months. For ALG, DH was superior to VC at months 2, 3, 4, 5, 6, 8, and 9 (P < or = 0.04 to 0.002) and superior to SC at months 5, 6, 7, 8, and 9 (P < or = 0.01 to 0.001) with a maximum ALG of 1.2 mm at 6 months. For BOP reduction, DH was superior to VC at all time points (P < or = 0.05) and to SC at months 3, 5, 6, 8, and 9 (P < or = 0.03). For DH, the maximum ALG in deep (> or = 7 mm) pockets was 1.7 mm and PDR 2.9 mm compared to 0.8 mm and 1.6 mm, respectively for moderate (5 to 6 mm) pockets. Test articles were applied without anesthesia and no serious adverse events occurred in the trial. The results of this study indicate that 10% doxycycline hyclate delivered in a biodegradable delivery system is an effective means of reducing the clinical signs of adult periodontitis and exhibits a benign safety profile.

Administration, Topical↗

PubMed1997

Periodontal regeneration in naturally occurring Class II furcation defects in beagle dogs after guided tissue regeneration with bioabsorbable barriers.

THE EFFICACY OF A BIOABSORBABLE polylactic acid based barrier was evaluated using naturally occurring buccal Class II furcation defects in beagle dogs. Sixteen furcation sites (8 control and 8 experimental) were treated in 6 adult animals. After full thickness flap reflection, exposed furcations and root surfaces were thoroughly root planed. In experimental sites a customized barrier was formed and fitted to cover the defect. Surgical flaps were replaced slightly coronal to the cemento-enamel junction. Animals were sacrificed at 6 months and specimens processed for histologic evaluation. Histologic and histometric analyses were done using 6 micrograms step serial sections in the buccal-lingual plane, corresponding to the buccal-lingual extent of the furcation. Results were: mean total defect experimental sites 1.92 mm; control sites 1.47 mm. Mean new cementum formation experimental sites 1.36 mm (71% of initial defect); control sites 0.25 mm (17% of initial defect). Mean new bone formation experimental sites 1.42 mm (74% of initial defect); control sites 0.20 mm (14% of initial defect). Mean junctional epithelium formation experimental sites 0.42 mm (22% of initial defect); control sites 1.21 mm (82% of initial defect). Statistical analysis demonstrated significant differences in all healing parameters favoring experimental (barrier-treated) sites. In this model, regeneration (new bone, cementum, and periodontal ligament) of 71% of the original defect in experimental sites and only 14% in control sites demonstrated a response that highly favored use of the barrier.

Alveolar Bone Loss↗

PubMed1997

Comparison of a bioabsorbable GTR barrier to a non-absorbable barrier in treating human class II furcation defects. A multi-center parallel design randomized single-blind trial.

This multi-center single-blind study compared clinical outcomes following guided tissue regeneration (GTR) treating human Class II furcation defects with a new polylactic-acid-based bioabsorbable barrier (test treatment) or a non-absorbable ePTFE barrier (control treatment). Clinical parameters evaluated were change in vertical attachment level (VAL), horizontal attachment level (HAL), probing depth (PD), and gingival margin location (REC). Surgical treatment resulted in clinically and statistically equivalent changes when comparisons were made between test and control treatments. VAL gain was 2.0 mm for test and 1.6 mm for control groups; HAL gain was 2.1 mm for both test and control groups. PD reduction was 2.3 mm for the test group and 2.1 mm for the control group. Test sites experienced an additional 0.3 mm of recession beyond baseline; control sites, 0.5 mm. Within-group comparisons showed that the amount of recession was not significantly different from baseline in the test group. Recession in the control group was significantly different from baseline. All other parameters in both the test and control groups were significantly different from baseline. Evaluation of safety data indicated no significant differences between test and control treatments, although there was a strong trend for the control group to have more postoperative abscess or suppuration than test sites (control = 11; test = 4; P = 0.06).

Absorption↗

PubMed1996

2 multi-center trials assessing the clinical efficacy of 5% sanguinarine in a biodegradable drug delivery system.

A biodegradable drug delivery system containing 5% sanguinarium (Sa) was compared to vehicle control (VC), scaling and root planing (SRP), and supragingival plaque control (SPC) in the treatment of adult periodontitis in 2 well-controlled clinical trials. Studies were 4-quadrant (split mouth) designs at 2 centers each, having 94 (Study A) and 107 (Study B) patients. All patients had at least 3 pockets between 5 and 9 mm that bled on probing, in each quadrant. Probing pocket depth (PD), clinical attachment level (AL), bleeding on probing (BOP), and plaque index were recorded at baseline, 14, 30, 60, and 90 days. All treatments gave statistically significant reductions from baseline for PD and BOP, and significant gains for AL. For PD reduction, SRP was superior to all test groups at all time points in both studies (p < 0.001). Sa was superior to VC in Study A at 14 and 30 days and to SPC at all time points. For AL gain at 90 days, in both studies, SRP gave gains of 0.42 and 0.78 mm respectively with superiority seen over the SPC group at 90 days (p < 0.001) in study A only, For BOP reduction, in Study A SRP was superior to Sa, VC, and SPC at 60 and 90 days (p < 0.005) and in Study B superiority to Sa and VC was at 90 days and to SPC at 60 days (p < 0.05). Sa was superior to VC for pocket depth in deep pockets only. Sa failed to demonstrate superiority over VC on a consistent basis. Analysis of residual Sa indicates that Sa potency was insufficient to show an advantage beyond clinical effects inherent in treatments with VC and SPC.

Adult↗

PubMed1996

Periodontal pocket treatment in beagle dogs using subgingival doxycycline from a biodegradable system. I. Initial clinical responses.

The present study evaluated the clinical response of periodontal pockets in beagle dogs after treatment with a biodegradable delivery system containing 10% doxycycline hyclate (ABDS-D). Eight adult, female beagle dogs had generalized, severe periodontitis with plaque and calculus-laden pockets. In each animal, 3 teeth with multiple pocket sites > or = 4 mm (mean depth = 6.0 mm) associated with attachment loss (mean = 5.4 mm) and which bled on probing (mean score = 2.5) were treated with a single application of either ABDS-D (experimental group) or the delivery system alone without the doxycycline (control group). Residual polymer was removed at day 7. Bioassay of doxycycline in gingival crevicular fluid associated with presence of ABDS-D gave mean levels of bioactivity of approximately 250 micrograms/ml. Levels of bioactive doxycycline were detected for approximately 7 days after ABDS-D removal. Periodontal maintenance consisted of thrice-weekly toothbrushing the treated sites. Clinical responses were evaluated at 2 weeks, and at bi-weekly intervals thereafter for 4 months. Analyses of the data from the control group showed that there was only slight clinical improvement. In contrast, in the experimental group, bleeding on probing and probing depths were significantly reduced from baseline at all post-treatment time points. At 1 month, mean probing depth reduction was 2.4 mm and this was maintained at 4 months (mean reduction = 2.5 mm). These probing depth reductions occurred primarily through gain of clinical attachment which was 2.0 mm at 4 months. Bleeding had been virtually eliminated (mean = 0.2). It was concluded that, for the beagle dogs with severely infected periodontal pockets in this study, treatment with subgingival doxycycline using the delivery system resulted in substantial improvement in periodontal health.

Administration, Topical↗

PubMed1996

Outcome failures of endosseous implants from a clinical training center.

In an effort to provide realistic clinical information from a "real-world" environment, the present retrospective study was undertaken to assess outcome failures after implant placement in a dental school clinical training center. A database was kept of the clinical information and was analyzed according to established parameters for implant outcomes. The demographics showed that over a period of 6 years, 80 different operators with a wide range of clinical experience had inserted 1,263 implants in a diverse patient pool of 380 individuals. Analysis of the outcomes showed a cumulative survival rate of 91.3%. The time of explantation, the type, size, and location of implants lost, and failure rates in smoking patients were also analyzed. The results indicated that the use of implants by operators with different levels of experience did not affect favorable outcomes.

Adult↗

PubMed1995

Whole mouth microbiota effects following subgingival delivery of sanguinarium.

An increased incidence of antibiotic-resistant bacteria and yeast overgrowth has been reported following various periodontal treatments. The objective of this study was to detect possible overgrowth of opportunistic bacteria and fungi as well as changes in normal microbiota after application of a biodegradable delivery system containing 5% sanguinarium (ABDS-S) to one quadrant in a split-mouth study. An oral hygiene quadrant served as a control. The ABDS-S treated and control periodontal sites as well as the saliva of 17 subjects were sampled prior to treatment, immediately after ABDS-S removal at 7 days, and again at 30 and 60 days. At Day 7 sanguinarium-resistant bacteria increased in both control and ABDS-S periodontal sites as well as in the saliva. Enteric Gram-negative bacilli in both control and ABDS-S periodontal sites were 2.2 to 3.4 log colony forming units higher at Day 7 compared to baseline. This overgrowth was transient in that levels became undetectable at Days 30 and 60. No such overgrowth was observed for C. albicans or other fungi, or for S. aureus or other staphylococci in any periodontal sites. Levels of Actinomyces increased at Days 30 and 60 in both control and ABDS-S sites as well as saliva. These changes strongly suggest that a 7 day ABDS-S treatment in one quadrant of the mouth led to significant microbiota changes in the treated and control quadrants as well as in the saliva. Future microbial studies involving antimicrobials delivered by local delivery systems must consider the crossover effects of treatment inherent in the split-mouth design.

Adult↗

PubMed1995

Guided tissue regeneration in human furcation defects after using a biodegradable barrier: a multi-center feasibility study.

This multi-center study evaluated guided tissue regeneration (GTR) in Class II furcation defects using a polylactic acid biodegradable barrier in 29 patients with mandibular and maxillary molar defects. Following an initial hygienic phase, surgical flaps were elevated, and the sites scaled and root planed. Furcation defect perimeter was measured and a customized barrier (thickness 600 to 750 mu) was applied to cover the defect. Barriers adhered directly to tooth and bone. At baseline, sites were measured for probing depth (PD) (6.0 +/- 0.2 [SE] mm), gingival margin location (GML) (-0.2 +/- 0.2 mm), and attachment level in both vertical (AL-V) (6.2 +/- 0.2 mm) and horizontal (AL-H) (5.4 +/- 0.2 mm) directions. After the surgical procedure, there was good compatibility between the gingival tissues and barrier material. Clinically, barriers fragmented and became displaced in 3 to 6 weeks. Substantial granulation tissue was sometimes present between barrier and root surfaces. Comprehensive periodontal examination parameters were measured 3, 4, 6, 9, and 12 months after baseline. A repeated measures ANOVA was used to evaluate changes from baseline. At 6 and 12 months postsurgery, GML was close to the presurgical level (-0.5 +/- 0.2 mm). There was clinically and statistically significant improvement in all other parameters: mean PD reduction (2.2 mm), AL-V gain (1.7 mm), and AL-H gain (2.5 mm). These results indicated favorable clinical regenerative outcomes after using this barrier material in Class II furcation defects in humans.

Adult↗

PubMed1995

Initial study of guided tissue regeneration in Class II furcation defects after use of a biodegradable barrier.

This study evaluated guided tissue regeneration in Class II furcation defects after use of a polylactic acid biodegradable barrier in nine patients with mandibular molar defects. Following an initial hygienic phase, surgical flaps were elevated, and the sites were scaled and root planed. Defect perimeter was measured, and a customized barrier (600 to 750 mm thick) that adhered directly to tooth and bone was applied. At baseline, sites were measured for probing depth (6.2 +/- 0.5 mm), gingival margin location (-0.6 +/- 0.6 mm), and attachment level both vertically (6.9 +/- 0.7 mm) and horizontally (5.3 +/- 0.5 mm). Clinically, barriers fragmented and became displaced in 3 to 6 weeks. Substantial granulation tissue was sometimes present between barrier and root surfaces. Six months postsurgery, gingival margin location was close to the presurgical level (-0.4 +/- 0.8 mm). There was clinically and statistically significant improvement in all other parameters: a mean reduction of 3.1 mm in probing depth, a gain of 3.3 mm in vertical attachment level, and a gain of 3.0 mm in horizontal attachment level. These results suggested favorable regenerative outcomes.

Adult↗