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Biomedical subjects

M K Jeffcoat

Publications and source records attributed to M K Jeffcoat.

At least 19 recordsLinked to original sources
PubMed2001

Periodontal infection and preterm birth: results of a prospective study.

BACKGROUND: Previous studies have suggested that chronic periodontal infection may be associated with preterm births. The authors conducted a prospective study to test for this association. METHODS: A total of 1,313 pregnant women were recruited from the Perinatal Emphasis Research Center at the University of Alabama at Birmingham. Complete periodontal, medical and behavioral assessments were made between 21 and 24 weeks gestation. After delivery, medical records were consulted to determine each infant's gestational age at birth. From these data, the authors calculated relationships between periodontal disease and preterm birth, while adjusting for smoking, parity (the state or fact of having born offspring), race and maternal age. Results were expressed as odds ratios and 95 percent confidence intervals, or CIs. RESULTS: Patients with severe or generalized periodontal disease had adjusted odds ratios (95 percent CI) of 4.45 (2.16-9.18) for preterm delivery (that is, before 37 weeks gestational age). The adjusted odds ratio increased with increasing prematurity to 5.28 (2.05-13.60) before 35 weeks' gestational age and to 7.07 (1.70-27.4) before 32 weeks' gestational age. CONCLUSIONS: The authors' data show an association between the presence of periodontitis at 21 to 24 weeks' gestation and subsequent preterm birth. Further studies are needed to determine whether periodontitis is the cause. CLINICAL IMPLICATIONS: While this large prospective study has shown a significant association between preterm birth and periodontitis at 21 to 24 weeks' gestation, neither it nor other studies to date were designed to determine whether treatment of periodontitis will reduce the risk of preterm birth. Pending an answer to this important question, it remains appropriate to advise expectant mothers about the importance of good oral health.

Adult↗
PubMed2001

Current evidence regarding periodontal disease as a risk factor in preterm birth.

Preterm birth, resulting in babies born too little and too soon, is a major cause of morbidity. Evidence indicates that infections can be major risk factors in preterm birth. Case-control studies point to an association between periodontal infection and increased rates of preterm birth. This paper summarizes evidence to date and the strategies that ongoing intervention studies are using to answer the fundamental clinical question: can periodontal therapy reduce the risk of preterm birth?

Case-Control Studies↗
PubMed2001

Implants in regenerated bone in a primate model.

BACKGROUND: Earlier publications from our laboratory described the use of guided bone regeneration to fill large bone voids in the mandible created through en bloc resection in primates. The present report describes placement of implants into the regenerated bone with subsequent prostheses construction and loading. METHODS: Lesions were created in the mandibles of 9 monkeys in a standardized mandibular defect of 8 x 19 mm. Reinforced expanded polytetrafluoroethylene membranes were placed in the animals and held in place with mini screws and sutures for anywhere from 1 to 12 months. No material was added to the defect. In each animal a root-form implant was placed 12 mm distal to the abutment teeth into the regenerated bone and was loaded with a prosthesis for 12 months. These implants were compared to original implants placed in the same monkeys years earlier in the same location in non-regenerated bone. Digital radiology and histomorphometry are described. RESULTS: The results show that root-form implants placed in regenerated bone show the same radiological and histomorphometric characteristics as in normal bone when loaded. In addition, the percentage of bone contact with implants seen in regenerated bone versus non-regenerated bone is the same when both are loaded (65 +/- 13% SD in regenerated bone versus 59 +/- 15% SD in non-regenerated bone). CONCLUSIONS: In a primate model root-form implants placed in regenerated bone and prosthetically loaded show no difference when compared to root-form implants placed in non-regenerated bone and prosthetically loaded.

Alveolar Bone Loss↗
PubMed2001

Intrapocket anesthesia for scaling and root planing: results of a double-blind multicenter trial using lidocaine prilocaine dental gel.

BACKGROUND: The efficacy of a novel anesthetic gel (lidocaine 25 mg/g plus prilocaine 25 mg/g in thermosetting agents) for non-invasive periodontal pocket anesthesia was evaluated. METHODS: One hundred twenty-two (122) patients in 8 centers with moderate to severe periodontitis requiring scaling and root planing (SRP) were enrolled in this multicenter, randomized, double-blind, controlled clinical trial. The active dental gel or a matching placebo gel was applied into the periodontal pocket using a blunt applicator. Following a waiting period of 30 seconds to 2 minutes, scaling and root planing were performed. If the patient had any discomfort, a second application of the gel was applied. If the patient continued to experience discomfort, conventional anesthesia was offered. After all teeth in the test quadrant had received SRP, the overall pain was assessed by the patient using a 100 mm horizontal, ungraded visual analog scale in which the left side was marked "no pain" and the right side marked "worst pain imaginable." Patients also assessed pain by using a 5-point verbal rating scale, from "no pain" to "very severe pain." RESULTS: The visual analog scale showed significant reductions in reported pain, favoring the active gel over the placebo (mean reduction, 8 mm; P <0.0005). The verbal rating scale revealed that 90% of patients treated with active gel reported no pain or mild pain compared to 64% of placebo-treated patients (P<0.001). CONCLUSIONS: Intrapocket administration of lidocaine 25 mg/g plus prilocaine 25 mg/g and thermosetting agents may be effective for pain control for scaling and root planing and may offer an alternative to infiltration anesthesia.

Administration, Topical↗
PubMed2001

Retrospective radiographic analysis of sinus graft and implant placement procedures from the Academy of Osseointegration Consensus Conference on Sinus Grafts.

A retrospective quantitative radiographic analysis determined the effect of graft material and smoking status on the maintenance of graft height over 3 years. Analysis of variance models with planned comparison were constructed to compare mean graft change by (1) graft material and (2) smoking status. Maintenance of bone height was significantly greater in intraoral autogenous grafts versus allografts (P < .05). The effect of smoking on implant loss revealed a significant difference in implant survival (P < .05). Autogenous bone generally resulted in a more favorable outcome over a 3-year period. Smoking adversely impacted implant survival in sinus grafts.

Alveolar Ridge Augmentation↗
PubMed2000

Persistent bacterial colonization of Porphyromonas gingivalis, Prevotella intermedia, and Actinobacillus actinomycetemcomitans in periodontitis and its association with alveolar bone loss after 6 months of therapy.

BACKGROUND, AIMS: The purpose of this study was to determine whether the presence of bacterial antigens for Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), and Actinobacillus actinomycetemcomitans (Aa) in subgingival plaque of periodontitis patients after periodontal treatment was associated with progressive alveolar bone loss. METHOD: 39 (39) subjects in good general health previously diagnosed with adult periodontitis within the last 2 years, and still presenting with probing depth >5 mm in 2 to 6 teeth, were studied. All subjects were treated with scaling and root planing. Half of the subjects were randomly assigned to receive adjunctive systemic doxycycline (200 mg the 1st day, then 100 mg per day for 21 days). Subgingival plaque samples were taken at baseline, 1, 3 and 6 months after therapy. A modified ELISA test (Evalusite, Periodontal Test Kit, Eastman Kodak Co., Rochester, NY) was used to test for plaque antigens associated with P. gingivalis, P. intermedia and A. actinomycetemcomitans. Progressive alveolar bone loss was determined using digital subtraction radiography with standardized radiographs taken at baseline and 6 months after treatment. RESULTS: The presence of P. gingivalis in plaque after treatment was significantly associated with progressive bone loss (positive predictive value 84%, negative predictive value 85%, odds ratio 31.9, p<0.0001). In contrast, the presence of P. intermedia in plaque after treatment was not indicative of progressive loss (positive predictive value 39%, negative predictive value 82%). Too few sites had evidence of A. actinomycetemcomitans to be amenable to statistical analysis. No significant difference in bone loss was attributable to the systemic antibiotic therapy. CONCLUSION: These data indicated that, in this population, the presence of P. gingivalis in plaque after treatment might be indicative of progressive alveolar bone loss.

Adult↗
PubMed2000

Advances in measurements of periodontal bone and attachment loss.

Periodontal probing and measurements using intraoral radiographs are widely utilized clinical techniques to measure attachment and bone levels, respectively. Determination of progressive disease, healing, or regeneration in clinical studies may require maximal sensitivity and attention to measurement error in order to assure that changes detected by new methodology are accurate. Both types of methods are susceptible to errors due to resolution, repeatability, and accuracy of the technique. While both probing and radiographic methods are useful in clinical trials they vary widely with respect to these errors. For example, manual probing is repeatable to within 1 mm better than 90% of the time, and state-of-the-art radiographic methods, such as digital subtraction radiography, can detect as little as 1 mg of bony change.

Alveolar Bone Loss↗
PubMed2000

Periodontal disease progression.

BACKGROUND: The objective of this investigation is to use noninvasive, state-of-the-art, diagnostic techniques to measure periodontal disease progression and model periodontal disease activity over time. In this investigation, digital subtraction radiography and an electronic controlled force periodontal probe capable of attachment level measurement were used to measure bone loss and attachment loss, respectively. The use of these nearly continuous measures of attachment and bone loss allowed detection of small amounts of disease activity and provided data to be used in modeling of the disease process over time. METHODS: Forty-four patients were studied for 18 months. Examinations used clinical attachment level measures at 1-month intervals and quantitative radiology at 6-month intervals. The sites were analyzed by regression for statistically significant changes. These data were used to determine sites of periodontal disease activity for testing various models of periodontal disease progression. RESULTS: Overall 22.8% of sites lost attachment, 5.4% gained, and 71.7% demonstrated no statistically significant change. The mean time to lose 1 mm of attachment was 8.4 +/- 0.6 months. In the first model tested a step-wise discriminant analysis was used to determine whether or not baseline measurements of plaque (PI), gingival inflammation (GI), attachment loss, and probing depth (PD) could be used to derive a satisfactory model for disease progression. Although the overall model was statistically significant with PI, PD, and GI contributing to the model (Wilks' lambda = 0.859, F = 5.71, P <0.0012), its predictive power was relatively weak. A considerably stronger significant model resulted when the rate of attachment loss over the first 6 months, baseline PI, and baseline GI were included (Wilks' lambda = 0.712, F = 14.17, P<0.00001). A significant model also resulted when bone loss during the first 6 months and baseline probing depth were included (Wilks' lambda = 0.438, F = 61.48, P<0.00001). When the last model was applied to each site, the sensitivity in predicting disease progression was 80.0% and the specificity in ruling out progressive disease was 93.9%. CONCLUSIONS: This study indicates that clinically significant progression of attachment loss in posterior tooth sites occurs as a frequent event in adult periodontitis. The modeling data also suggest that short-term (6 month) measures of periodontal disease progression greatly improve the ability to model attachment loss over a longer period in untreated periodontitis patients.

Calibration↗
PubMed2000

Use of a biodegradable chlorhexidine chip in the treatment of adult periodontitis: clinical and radiographic findings.

BACKGROUND: Previous multi-center trials demonstrated the efficacy of a biodegradable chlorhexidine-gelatin chip (CHX) in reducing probing depth in patients with periodontitis. The present study utilized a subset of subjects from the parent study to determine if the CHX chip was effective in maintaining alveolar bone over a 9-month period. METHODS: Forty-five subjects with at least four 5 to 8 mm pockets, stratified by smoking status, were enrolled in this double-blind controlled, placebo-controlled trial. Control groups received either placebo chip plus scaling and root planing (SRP) or SRP alone. Test group subjects received active CHX chip or SRP alone (to maintain the blind). Standardized radiographs were taken for quantitative digital subtraction radiography at baseline and 9 months. RESULTS: At 9 months, 15% of SRP treated subjects experienced loss of bone in 1 or more sites, no subject treated with active chip plus SRP lost bone (P <0.01). At 9 months, significant differences in the change in probing depth and clinical attachment levels favoring the active chip over SRP alone or SRP plus CHX chip were also observed (P <0.05). CONCLUSIONS: These data indicate that the CHX chip, when used as an adjunct to scaling and root planing, significantly reduces loss of alveolar bone.

Adult↗
PubMed2000

Guided bone regeneration of large mandibular defects in a primate model.

BACKGROUND: An earlier publication from our laboratory described the use of guided bone regeneration to fill large bone voids in the mandible created through en bloc resection in primates. The present report is an embellishment of this paper and describes bone regeneration experiments in 18 adult male Macaca mulatta monkeys to determine how long membranes must be in position to promote guided bone regeneration. METHODS: Thirty-six lesions were created in the mandibles of 18 monkeys in a standardized mandibular defect of 8 x 19 mm. Reinforced ePTFE membranes were placed in the animals and held in place with mini screws and sutures for anywhere from 1 to 12 months. No material was added to the defect. In addition to clinical studies, digital subtraction radiology and fluorescent labeling with tetracycline and histomorphometry are described. RESULTS: The results indicate that no bone gain was observed in membranes exposed for 1 month or less, but bone gain (approximately well over 90% of defects) was observed at 12 months when membranes were left in situ for 2 to 12 months (P <0.0001). No significant difference in the amount of bone gained at 12 months was observed for membranes left in place for intervals ranging from 2 to 12 months. A significant correlation between the amount of bone gain observed at 3 and 12 months was observed (P <0.0001). CONCLUSIONS: Data therefore suggest that membranes left in situ for 1 month or less result in minimal bone gain compared with membranes left in place from 2 to 12 months. In addition, labeling and stained sections clearly showed that the bone produced after 2 months of membrane placement is mature.

Animals↗
PubMed2000

Preterm birth, osteoporosis, and periodontal disease.

The purpose of this two-part article is to review two major events in the life span of a woman. These include the putative relationship between oral health, pregnancy, and postmenopausal osteoporosis. Current knowledge about risk factors for preterm birth and for osteoporosis are discussed. The newest studies that address the relationship between oral and systemic health are also reviewed.

Adolescent↗
PubMed1999

The cost-effectiveness of a new chlorhexidine delivery system in the treatment of adult periodontitis.

BACKGROUND: Periodontal treatment is costly. The authors assessed the potential economic impact of a new periodontal chemotherapeutic, testing the hypothesis that its adjunctive use would result in reduced periodontal surgical needs. METHODS: An economic model estimated treatment needs following two clinical trials of the adjunctive use of a chlorhexidine, or CHX, -containing chip compared with scaling and root planing, or SRP, alone. Needs were based on periodontal status at nine months and a probabilistic algorithm; costs were assigned on the basis of a national dental survey and an average wholesale price of the CHX chip. RESULTS: The base case model projected significantly more maintenance procedures and significantly fewer periodontal surgical procedures for patients treated with SRP and the CHX chip compared with patients who were treated with SRP alone (54.4 percent vs. 46.4 percent, P = .014; 29.2 percent vs. 35.5 percent, P = .015, respectively). Average total costs of care for patients treated with SRP and CHX chip were $737 +/- $244 compared with $734 +/- $239 for patients treated with SRP alone. Sensitivity analyses to account for variations in practice patterns did not appreciably alter the results. When data were analyzed after only three or six months of treatment, the significant differences in treatment needs disappeared. CONCLUSIONS: The CHX chip is a new, apparently cost-effective treatment option for non-surgical periodontal therapy. Adjunctive use of the CHX chip could reduce periodontal surgical needs significantly at little or no additional cost. CLINICAL IMPLICATIONS: Results suggest that incorporating the CHX chip into routine practice requires a new algorithm for management of periodontal disease. To obtain full clinical benefit, treatment needs to be continued for nine months.

Adult↗
PubMed1999

Progression and treatment of chronic adult periodontitis.

BACKGROUND: The periodontal status of 41 medically healthy adults with untreated chronic periodontitis was monitored before and after scaling and root planing (SRP). METHODS: During a 6-month pretreatment phase, clinical measurements, digital subtraction radiography (DSR) analysis of alveolar bone, and measurement of gingival crevicular fluid (GCF) prostaglandin E2 (PGE2) levels were undertaken. SRP was provided during a 1-month treatment phase. Clinical, radiographic, and biochemical analyses were repeated in a 6-month post-treatment healing period. RESULTS: Pretreatment: no clinically significant changes in mean plaque indices (PI), probing depths (PD), bleeding on probing (BOP), or relative clinical attachment levels (CAL) were detected (P>0.05). DSR revealed small but statistically significant bone height (0.04 mm) and mass (0.97 mg) loss (P<0.001). GCF PGE2 levels gradually increased from 38.8 ng/ml at month 1 to 79.4 ng/ml at month 6. Post-treatment: statistically and clinically significant reductions were observed in mean PI, BOP, and PD (P<0.05). A statistically significant reduction in CAL was noted (P<0.05). The trend towards progressive bone loss was halted and reversed, and a statistically significant decrease in GCF PGE2 concentrations was detected (P<0.001). Smokers, non-smokers, and ex-smokers did not differ significantly in PI, BOP, CAL, radiographic, or biochemical parameters at any time. Mean PD was significantly greater in current smokers than in non- and ex-smokers (P<0.005). PD reduced comparably in all 3 smoking subgroups following treatment (P<0.01). CONCLUSIONS: Conventional clinical measurements failed to identify disease progression over a 6-month period. Significant improvements were observed in clinical parameters after SRP, and a trend towards progressive bone loss was halted and reversed. Regular and frequent maintenance visits are important following treatment to maintain improvements in clinical parameters. Smokers had deeper probing depths than non- and ex-smokers, but pockets were reduced significantly and comparably in all 3 smoking subgroups following efficacious treatment.

Adult↗
PubMed1998

Semiautomated image registration for digital subtraction radiography.

OBJECTIVE: The purpose of this study was to evaluate the semiautomatic alignment and correction of affine geometric discrepancies for digital subtraction radiography. STUDY DESIGN: Algorithms were tested in vitro to determine their ability to semiautomatically select reference points on a second image based on points selected on a first (reference) image. A preserved human mandible was imaged with and without bone-equivalent material chips at varying degrees of angulation. Each chip had a mass of less than 10 mg and was no more than 0.3 mm thick. High levels of specificity and sensitivity for chip detection were achieved with 6 degrees of angular discrepancy or less. The algorithms were then applied to radiographs from six human subjects through use of the bone-chip validation model. RESULTS: Sensitivity was 89% and 100% for the three-point and four-point affine warp algorithms, respectively. Specificity for both algorithms was 100%. CONCLUSIONS: The data indicate that semiautomated alignment algorithms may enhance the efficacy of digital subtraction radiography while maintaining diagnostic efficacy in clinical trials.

Algorithms↗
PubMed1998

Longitudinal changes in TCRB variable gene expression and markers of gingival inflammation in experimental gingivitis.

The aim of this study was to gain information of the cellular and molecular events which occur during the development of experimental gingivitis and to determine whether such changes occur in the presence or absence of alveolar bone resorption. Clinical, radiographic, biochemical and immunological variables were monitored in a 3-week, single-centre, experimental gingivitis study of 10 healthy volunteers. Following screening and professional prophylaxis to achieve visibly healthy gingival status, subjects abstained from all oral hygiene practises in one maxillary (test) quadrant for a period of 21 days. At days 0 and 21, in test and (contralateral) control quadrants, % bleeding on controlled pressure probing (% BOP) was calculated, and radiographic alveolar bone status was assessed using bilateral standardised vertical bite-wing radiographs and digital subtraction radiography (DSR) analysis. In test quadrants, gingival crevicular fluid (GCF) was sampled from 4 sites per subject with Periopaper strips, and prostaglandin E2 (PGE2) levels measured using an enzyme immunoassay (EIA) kit. At days 0, 7 and 21, one interdental papilla was surgically excised from the test quadrant, and the expression of T cell receptor B variable (TCRBV) genes was investigated using a reverse transcription-polymerase chain reaction (RT-PCR) procedure. At days 0, 7 and 21, peripheral blood lymphocytes (PBL) were isolated and additionally investigated for TCRBV gene expression. Following 21 days of plaque accumulation in test quadrants, a statistically significant increase in % BOP scores confirmed the presence of gingival inflammation (p<0.001). DSR analysis revealed that there were no significant alveolar bone changes in either the test or control quadrants between days 0 and 21 (p>0.05). EIA analysis of GCF samples identified a significant decrease in mean GCF PGE2 concentrations from day 0 to day 21 (p<0.05). RT-PCR analysis indicated that genes from all 3 TCRBV families studied (TCRBV-2, -6, -8) were expressed in the PBL samples at all time points and in healthy gingival tissues at day 0. A restriction in the expression pattern of TCRBV genes similar to those which have previously been reported in chronic periodontitis was noted at gingivitis sites. It is possible that such an event may identify susceptibility to periodontal disease independently of other positive predictive markers such as GCF-PGE2.

Adolescent↗