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Biomedical subjects

Michael S Reddy

Publications and source records attributed to Michael S Reddy.

11 recordsLinked to original sources
PubMed2005

Platelet-derived growth factor stimulates bone fill and rate of attachment level gain: results of a large multicenter randomized controlled trial.

BACKGROUND: Growth factors are generally accepted to be essential mediators of tissue repair via well-established mechanisms of action that include stimulatory effects on angiogenesis and cellular proliferation, ingrowth, differentiation, and matrix biosynthesis. The aim of this study was to evaluate in a large-scale, prospective, blinded, and randomized controlled clinical trial the safety and effectiveness of purified recombinant human platelet-derived growth factor (rhPDGF-BB) mixed with a synthetic beta-tricalcium phosphate (beta-TCP) matrix for the treatment of advanced periodontal osseous defects at 6 months of healing. METHODS: Eleven clinical centers enrolled 180 subjects, each requiring surgical treatment of a 4 mm or greater intrabony periodontal defect and meeting all inclusion and exclusion criteria. Subjects were randomized into one of three treatment groups: 1) beta-TCP + 0.3 mg/ml rhPDGF-BB in buffer; 2) beta-TCP + 1.0 mg/ml rhPDGF-BB in buffer; and 3) beta-TCP + buffer (active control). Safety data were assessed by the frequency and severity of adverse events. Effectiveness measurements included clinical attachment levels (CAL) and gingival recession (GR) measured clinically and linear bone growth (LBG) and percent bone fill (% BF) as assessed radiographically by an independent centralized radiology review center. The area under the curve (AUC), an assessment of the rate of healing, was also calculated for CAL measurements. The surgeons, clinical and radiographic evaluators, patients, and study sponsor were all masked with respect to treatment groups. RESULTS: CAL gain was significantly greater at 3 months for group 1 (rhPDGF 0.3 mg/ml) compared to group 3 (beta-TCP + buffer) (3.8 versus 3.3 mm; P = 0.032), although by 6 months, this finding was not statistically significant (P = 0.11). This early acceleration of CAL gain led to group 1 exhibiting a significantly greater rate of CAL gain between baseline and 6 months than group 3 as assessed by the AUC (68.4- versus 60.1-mm weeks; P = 0.033). rhPDGF (0.3 mg/ml)-treated sites also had significantly greater linear bone gain (2.6 versus 0.9 mm, respectively; P < 0.001) and percent defect fill (57% versus 18%, respectively; P < 0.001) than the sites receiving the bone substitute with buffer at 6 months. There was less GR at 3 months in group 1 compared to group 3 (P = 0.04); at 6 months, GR for group 1 remained unchanged, whereas there was a slight gain in gingival height for group 3 resulting in comparable GR. There were no serious adverse events attributable to any of the treatments. CONCLUSIONS: To our knowledge, this study is the largest prospective, randomized, triple-blinded, and controlled pivotal clinical trial reported to date assessing a putative periodontal regenerative and wound healing therapy. The study demonstrated that the use of rhPDGF-BB was safe and effective in the treatment of periodontal osseous defects. Treatment with rhPDGF-BB stimulated a significant increase in the rate of CAL gain, reduced gingival recession at 3 months post-surgery, and improved bone fill as compared to a beta-TCP bone substitute at 6 months.

Adult↗
PubMed2005

Radiographic alveolar bone change as an outcome measure for therapies that inhibit bone loss or foster bone gain.

Periodontal clinical trials rely on signs of gingival inflammation, periodontal probing methods, and intra-oral radiographic methods to measure outcomes of therapies that inhibit bone loss or foster bone gain. A single radiograph can provide information on the accumulation of past disease, and sequential radiographs can determine regeneration or progression of periodontal destruction. However, the precision achieved with a radiograph is associated with the actual exposure of the film and the subsequent analysis. A film exposed using standardized geometry and standardized processing has many advantages over non-standardized conventional film. If the patient population for a study is a small, selective group, or if one needs to identify the smallest amount of bone loss in the shortest time, standardized films may be used. Conversely, in a large-scale trial, the use of standardized films may prove to be impractical. Since the advent of personal computer-based image-processing workstations, digital-image analysis has also become a practical tool for clinical trials. Digital subtraction radiography is a highly precise and accurate technique for assessing bony changes associated with periodontal disease. Therefore, advanced digital-imaging systems may be more cost-effective in a clinical trial because the level of precision will have an effect on study length and sample size.

Alveolar Bone Loss↗
PubMed2003

Achieving gingival esthetics.

INTRODUCTION: Dentists traditionally have thought of periodontal treatment as a means of saving the teeth while leaving the patient with an esthetic problem. This no longer is true. The goal of this article is to show how esthetic crown-lengthening procedures, papillary regeneration and root coverage may enhance the overall esthetic results of periodontal treatment. METHODS AND RESULTS: Esthetic crown lengthening aims not only to provide biological width for the healthy restoration of teeth, but also to permit esthetic gingival and prosthetic contours. Papillary regeneration aims to fill the dark spaces that may occur interproximally with the progression of periodontitis or as a result of tooth alignment. Finally, root coverage procedures now can provide predictable results with the application of connective-tissue periodontal grafts and plastic surgery techniques. This article presents a case report for each type of procedure, each of which resulted in improved esthetics and cosmetic appearance. CLINICAL IMPLICATIONS: Periodontal treatment now is part of the solution for certain esthetic problems. While technically demanding, these procedures, in the hands of an appropriately trained and experienced clinician, can improve the overall results of patient treatment.

Connective Tissue↗
PubMed2003

Periodontal host modulation with antiproteinase, anti-inflammatory, and bone-sparing agents. A systematic review.

BACKGROUND: The use of modulating agents, including inhibition of matrix metalloproteinases (MMPs) with antiproteinases, blocking production of proinflammatory cytokines and prostaglandins with anti-inflammatory drugs, and inhibiting activation of osteoclasts with bone-sparing agents, has been postulated to be of therapeutic value as an adjunctive therapy to the management of chronic periodontitis. RATIONALE: The objective of this systematic review of the literature was to assess the adjunctive efficacy of antiproteinase, anti-inflammatory, and bone-sparing host-modulating agents in the treatment of gingivitis, aggressive periodontitis, and chronic periodontitis. FOCUSED QUESTIONS: 1. In patients with periodontal diseases, what is the effect of host-modulation agents, alone or combined with conventional therapy, compared to conventional therapy alone as assessed by clinical, radiographic, adverse, and patient-centered outcomes? 2. In patients with dental implants, what is the effect of host-modulation agents on implant success assessed by clinical, radiographic, adverse, and patient-centered outcomes? SEARCH PROTOCOL: MEDLINE, Embase, and the Cochrane Library databases were searched without language restrictions through April 1, 2002 for studies that used tetracycline (TET)-related matrix metalloproteinase (MMP) inhibitors, or non-steroidal anti-inflammatory drugs (NSAIDs) and bisphosphonate anti-osteolytic agents. The investigation also included hand searching of journals and contacting authors and industry experts. SELECTION CRITERIA INCLUSION CRITERIA: Only human studies (randomized controlled clinical trials, cohort studies, case-control studies, cross-sectional studies, and case series) were selected. Studies were on subjects with gingivitis, aggressive or chronic periodontitis, or dental implants. Interventions included TET-related MMP inhibitors, NSAIDs, or bisphosphonate anti-osteolytic agents. EXCLUSION CRITERIA: Studies that used MMP tissue inhibitors as diagnostic or prognostic indicators of periodontal disease or that evaluated short-term systemic antibodies or locally delivered levels of drugs with antiproteinase activity were excluded. DATA COLLECTION AND ANALYSIS: The primary outcomes for assessment were changes in bone or clinical attachment levels (CAL); secondary outcomes included clinical measures of plaque, gingival inflammation, probing depth (PD), and mobility. Summary data appropriate for meta-analysis were pooled using a weighted average and analyzed using a standardized difference; the results were checked with both fixed-effects and random-effects models. MAIN RESULTS: 1. A meta-analysis done on the studies reporting changes in CAL and PD following administration of sub-antimicrobial doses of doxycycline (SDD) in conjunction with scaling and root planing (SRP) in patients with periodontitis showed a statistically significant beneficial adjunctive effect. 2. There were insufficient data to provide meta-analyses on periodontal patients treated with other host-modulating agents; descriptive tables are included. 3. NSAIDS show promise in their ability to slow periodontal disease. 4. Preliminary data on bisphosphonate agents indicate there is a potential role for these agents in periodontitis management. 5. There are a very limited number of studies on host-modulating agents and dental implants and no analyses were possible. 6. Because the treatment methodologies and clinical variables differed considerably among the studies, it is difficult to summarize the information and identify a reliable total patient population. REVIEWERS' CONCLUSIONS: 1. Large multi-center trials are needed to evaluate the role of host-modulating agents in the treatment of periodontitis. 2. NSAIDS and bisphosphonate drugs may have a potential adjunctive role in periodontal therapy. 3. The adjunctive use of SDD with SRP is statistically more effective than SRP alone in reducing PD and in achieving CAL gain.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2003

Efficacy of controlled-release subgingival chlorhexidine to enhance periodontal regeneration.

BACKGROUND: Periodontal regeneration success may be limited by placing bone grafts and membranes in infected sites. The objective of this study was to test the hypothesis that adjunctive subgingival administration of chlorhexidine gelatin bioresorbable chips enhances bone gain when used in conjunction with guided tissue regeneration. METHODS: This was a single center, blinded, 2-arm parallel design study of 44 subjects with one or more sites with probing depth and clinical attachment loss > or = 5 mm following initial therapy and radiographic evidence of bone loss. The patients were randomly assigned to receive either chlorhexidine (CHX) chip or sham chip placement one week prior to regenerative therapy that included graft placement and site coverage with guided tissue membranes. Patients also received CHX or sham chip placement, per their randomization, adjunctively to scaling and root planing or maintenance procedures. Periodontal examinations were completed at baseline (8 weeks prior to surgery); 1 week prior to surgery; and at 3, 6, and 9 months postsurgery. The major outcomes for the study were changes in bone height and bone mass as measured from standardized radiographs used for quantitative digital subtraction radiography over the 11-month study period. RESULTS: Subjects receiving sham chip placement gained a mean bone height of 1.49 +/- 0.22 mm, while patients receiving the CHX chips gained significantly more bone height (3.54 +/- 0.45 mm; P<0.001). Similarly, subjects receiving CHX chips as an adjunct gained significantly more bone mass (5.57 +/- 0.69 mg; P<0.001) than the standard therapy (2.59 +/- 0.34 mg). CONCLUSIONS: These pilot results indicate that locally delivered, controlled-release antimicrobial treatment may improve the amount of bone gain during guided tissue regeneration procedures. These data support the evidence that infection control is an important variable in successful regeneration.

Adult↗
PubMed2003

Periodontal disease and preterm birth: results of a pilot intervention study.

BACKGROUND: Previous case-control and prospective studies have shown an association between the presence of periodontitis and the risk of preterm birth (PTB). The goal of this pilot trial was to determine the feasibility of conducting a trial to determine whether treatment of periodontitis reduces the risk of spontaneous preterm birth (SPTB). METHODS: Three hundred sixty-six (366) women with periodontitis between 21 and 25 weeks' gestation were recruited and randomized to one of three treatment groups with stratification on the following two factors: 1) previous SPTB at <35 weeks and 2) body mass index <19.8 or bacterial vaginosis as assessed by Gram stain. The treatment groups consisted of: 1) dental prophylaxis plus placebo capsule; 2) scaling and root planing (SRP) plus placebo capsule; and 3) SRP plus metronidazole capsule (250 mg t.i.d. for one week). An additional group of 723 pregnant women meeting the same criteria for periodontitis and enrolled in a prospective study served as an untreated reference group. RESULTS: The rate of PTB at <35 weeks was 4.9% in the prophylaxis group, compared to 3.3% in the SRP plus metronidazole group and 0.8% in the SRP plus placebo group (P = 0.75 and 0.12, respectively). The rate of PTB at <35 weeks was 6.3% in the reference group. CONCLUSIONS: This trial indicates that performing SRP in pregnant women with periodontitis may reduce PTB in this population. Adjunctive metronidazole therapy did not improve pregnancy outcome. Larger trials will be needed to achieve statistical significance, especially at less than 35 weeks gestational age.

Adult↗
PubMed2002

Mandibular growth following implant restoration: does Wolff's law apply to residual ridge resorption?

This study measured bone height under a fixed detachable cantilever restoration supported by five or six endosseous implants in 60 consecutively treated patients. Panoramic films were made at surgery and 1, 2, 3, and 4 years postrestoration. A computer-enhanced method was used to measure mandibular height 5, 10, 15, and 20 mm distal to the last implant, which was used as a length. standard to correct for variation in film magnification. Implant restoration resulted in a significant growth of the mandible (baseline: 7.25 +/- 0.25 mm, 4 years: 8.18 +/- 0.18 mm; P = .05). The growth in dimension appears to occur during the first year of function.

Analysis of Variance↗
PubMed2002

Oral osteoporosis: is there an association between periodontitis and osteoporosis?

Osteoporosis and periodontitis represent two highly prevalent diseases associated with advancing age. There is evidence that a patient with systemic osteoporosis is likely to have decreased oral bone density, which may affect treatment decisions. Further, a patient with decreased bone mineral density, indicative of osteoporosis, may be at a higher risk for periodontitis progression. Therefore, osteoporosis could be considered a risk factor for periodontitis. Ultimately, many of the medical, nutritional, and lifestyle interventions that are beneficial in the management of osteoporosis have the potential to be applied to oral health care and the management of oral bone loss.

Absorptiometry, Photon↗
PubMedDate not supplied

Influence of implant geometry and surface characteristics on progressive osseointegration.

PURPOSE: Although no currently available technique for the measurement of osseointegration is entirely satisfactory, 3 clinical variables can be reasonably associated with the process: probing depth, micromobility, and crestal bone height. Micromobility can be quantified to some extent with the use of the Periotest, a commercially available instrument In this investigation, the influence of surface characteristics and geometry upon Periotest value (PTV) and probing depth measurements was studied. MATERIALS AND METHODS: In a multicenter trial, 120 healthy edentulous patients received 5 or 6 implants in the anterior mandible and were followed for 3 years. A total of 634 implants were placed. Every patient received at least 1 implant of each of 3 types: threaded titanium plasma-sprayed (TPS), threaded hydroxyapatite-coated (HA), and cylindric HA-coated. A randomization schedule assured that approximately equal numbers of each type of implant were placed and that they were uniformly distributed over the arch. RESULTS: Of the 4 tested combinations of dependent and independent variables, the only statistically significant (P < .05) effect was that of coating on PTV. At 1 year after prosthetic restoration, the mean PTV for HA-coated threaded implants was -5.36 +/- 1.24, compared with -4.86 +/- 1.70 for TPS implants. This difference steadily declined in magnitude and significance, until, after 3 years, the groups were indistinguishable. DISCUSSION: This study agrees with the previous observations that HA coating tends to accelerate the initial rate of osseointegration. The absence of a difference between threaded and cylindric implants confirms that the PTV responds to micromobility near the surface, on a scale much smaller than such gross geometric features. CONCLUSION: On the basis of these results, one may conclude that HA-coated implants exhibit a more rapid decrease in micromobility than do TPS implants of identical geometry.

Coated Materials, Biocompatible↗
PubMedDate not supplied

A comparison of hydroxyapatite (HA) -coated threaded, HA-coated cylindric, and titanium threaded endosseous dental implants.

PURPOSE: The purpose of this study was to compare the success of hydroxyapatite (HA) -coated and machined titanium (Ti) implants in a 5-year randomized, controlled clinical trial conducted at 2 centers. MATERIALS AND METHODS: Each of 120 edentulous patients received HA-coated threaded, HA-coated cylindric, and machined Ti threaded implants in a randomized design using 5 or 6 implants. Digital radiographs allowed for yearly measurements of bone loss. Calibrated clinicians also measured mobility, Gingival Index, Plaque Index, probing depth, and recession. A Kaplan-Meier analysis was used to compare the proportion of ailing implants (defined as less than 2 mm of alveolar bone loss over 5 years) for each type of implant design. The criteria employed to assess implant outcome included the need for successful implants to lose less than 2 mm of bone support over the 5 years following placement of the prosthesis. RESULTS: This analysis revealed that 95.2% of machined Ti threaded implants and 97.92% of HA-coated threaded implants were successful, while 99.0% of HA-coated cylindric implants experienced less than 2 mm of bone loss (P < .06). DISCUSSION: All types of implants placed in this study had success rates above 95%. CONCLUSION: Over 5 years, the success rate tended to favor HA-coated implants.

Adolescent↗