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A biologic is a therapeutic agent with biological activity that is administered to achieve an enhanced regenerative or reparative effect. The use of biologics has progressively become a core component of contemporary periodontal practice. However, some questions remain about their safety, indications, and effectiveness in specific clinical scenarios. Given their availability for routine clinical use and the existing amount of related evidence, the goal of this American Academy of Periodontology (AAP) best evidence consensus (BEC) was to provide a state-of-the-art, evidence-based perspective on the therapeutic application of autologous blood-derived products (ABPs), enamel matrix derivative (EMD), recombinant human platelet-derived growth factor BB (rhPDGF-BB), and recombinant human bone morphogenetic protein 2 (rhBMP-2). A panel of experts with extensive knowledge on the science and clinical application of biologics was convened. Three systematic reviews covering the areas of periodontal plastic surgery, treatment of infrabony defects, and alveolar ridge preservation/reconstruction and implant site development were conducted a priori and provided the foundation for the deliberations. The expert panel debated the merits of published data and exchanged experiential information to formulate evidence-based consensus statements and recommendations for clinical practice and future research. Based on an analysis of the current evidence and expert opinion, the panel concluded that the appropriate use of biologics in periodontal practice is generally safe and provides added benefits to conventional treatment approaches. However, therapeutic benefits and risks range based on the specific biologics used as well as patient-related local and systemic factors. Given the limited evidence available for some indications (e.g., gingival augmentation therapy, alveolar ridge preservation/reconstruction, and implant site development), future clinical studies that can expand the knowledge base on the clinical use of biologics in periodontal practice are warranted.

BACKGROUND The autogenous connective tissue graft (CTG) with coronally advanced flap (CTG+CAF) is the "gold standard" for recession defect coverage; however, researchers continue to pursue lower morbidity, more convenient and unlimited supply harvest graft substitutes, including those that could provide soft tissue volume augmentation. METHODS A randomized, controlled, double-masked comparison of a volume-stable collagen matrix (VCMX) versus CTG was conducted at four clinical investigation sites. Single, contralateral, within patient matched-pair, RT1 recession defects were treated with VCMX+CAF (test) and CTG+CAF (control). The primary efficacy end point was percent root coverage at 6 months. Secondary efficacy end points included clinical measures such as soft tissue volume, attachment level, and keratinized tissue width. Patient-reported outcomes included measures such as discomfort, esthetics, and overall satisfaction; 6-month end point results were followed for 1 year. RESULTS Thirty patients received control and test therapies, and all patients were available for follow-up measures. Average percent root coverage for CTG+CAF was 90.5% ± 14.87% versus 70.7% ± 28.26% for VCMX+CAF, P

Background The purpose of this publication is to report on the six-month clinical results and patient reported outcomes (PROs) comparing the surgical use of the Er,Cr:YSGG laser (ERL) and minimally invasive surgical technique (MIST) for the treatment of intrabony defects in subjects with generalized periodontitis stage III, grade B. Methods Fifty-three adult subjects (29 females and 24 males; 19 to 73 years) with 79 intrabony defects were randomized following scaling and root planing (SRP) to receive ERL monotherapy (n = 27) or MIST (n = 26). Recession (REC), probing depth (PD), clinical attachment level (CAL), treatment time, and PROs were assessed and compared for each treatment group. Clinical measurements were recorded at baseline, 4-6 weeks following SRP, and six months following surgical therapy. Results The following primary and secondary outcome variables were non-inferior with the following margins: CAL with a non-inferiority margin of 0.6 millimeters (mm). (p = 0.05), PD with a non-inferiority margin of 0.5 mm. (p = 0.05), Recession with a non-inferiority margin of 0.4 mm (p = 0.05). Faster procedure times were found for ERL (16.39 ± 6.21 minutes) vs MIST (20.17 ± 5.62 minutes), p = 0.0002. In the first two to three days of post therapeutic diary outcomes, subjects reported less bruising, facial swelling, and use of Ice pack for the ERL group. Conclusions This is the first multicenter, randomized, blinded, and controlled study demonstrating the Er,Cr:YSGG laser is not inferior to MIST in terms of clinical outcomes but is superior in PROs for the surgical treatment of intrabony defects. This article is protected by copyright. All rights reserved.

Nucleic acid sensing has emerged as one of the important components of the immune system triggering inflammation. The aim of this study is to determine the expression of bacterial DNA sensors, including Toll-like receptor 9 (TLR-9), DNA-dependent activator of interferon-regulatory factors (DAI), and absent in melanoma 2 (AIM2) in chronic periodontitis (CP versus healthy) (H) tissues.Thirty-five CP and 27 H gingival biopsies were included. Real-time quantitative polymerase chain reaction was performed to determine mRNA levels of AIM2, DAI, and TLRs (TLR-1 through TLR-9). The difference in gene expression for each sensor between CP and H tissues was calculated using analysis of covariance. The Spearman test was used to determine correlations among innate receptors. The expression of TLR-9, AIM2, and DAI in gingival tissues was further confirmed using immunohistochemistry.The present results reveal statistically significant upregulation of TLR-9 (P0.006), DAI (P0.001), and TLR-8 (P0.01) in CP tissues compared to H sites. Although mRNA expression was not changed significantly between groups for other receptors, the present results reveal significant correlations between receptors (P0.05), suggesting that cooperation between multiple components of the host immune system may influence the overall response. Immunohistochemistry further confirmed expression of TLR-9, AIM2, and DAI in gingival tissues.This study highlights a possible role for nucleic acid receptors in periodontal inflammation. Future investigations will determine whether cytoplasmic receptors and their ligands can be targeted to improve clinical outcomes in periodontitis.

Smile esthetics have been shown to play a major role in the perception of whether a person is attractive, and whether they are perceived as friendly, trustworthy, intelligent, and self-confident. A proposed major determinant of the esthetics of a smile is the amount of gingival display, which can be excessive in cases of altered passive eruption. The aim of this study is to see whether altering the amount of gingival display of patients would affect dental professionals' and laypersons' perceptions of the aforementioned social parameters.Patients were identified as having altered passive eruption and excessive gingival display. Smiling "control" photographs were taken and then digitally altered so as to lengthen the teeth and thus reduce the amount of gingival display. These became the "test" photographs. The control and test photographs were shown in random order. The control group of evaluators consisted of senior dental students, and the test group of evaluators comprised students who had no formal dental training. Groups were asked to rate, on a visual analog scale, each picture's attractiveness, friendliness, trustworthiness, intelligence, and self-confidence.The test pictures with less gingival display were consistently and statistically significantly rated higher for all five social parameters than were their control counterparts (P0.0001). When analyzed as an isolated effect, there were no statistically significant differences between the control group and the test group of evaluators when rating the pictures. Pictures depicting African Americans were judged to be more trustworthy (P = 0.0467) and self-confident (P = 0.0490) than pictures depicting white individuals. Pictures depicting women were judged to be more trustworthy (P = 0.0159) and intelligent (P = 0.0329) than pictures depicting men. All the social parameters were positively and statistically significantly correlated with each other (P0.0001).Excessive gingival display did negatively affect how attractive a person's smile is judged to be. In addition, how friendly, trustworthy, intelligent, and self-confident a person was perceived to be was inversely related to the amount of gingival display. Untrained laypeople were just as sensitive to these differences as senior dental students.

It was hypothesized that if periodontal infections predispose low birth weights and premature birth, then such outcomes should be apparent when the mother has aggressive periodontitis (AgP).Birth weight data were collected by questionnaire from females with AgP, their periodontally healthy siblings, and unrelated periodontally healthy women. Both prospective and retrospective birth outcome data were used. Because many of the periodontal evaluations were performed after the births, there were incomplete data regarding most of the risk factors for low birth weight. We determined associations between mothers' periodontal diagnoses and clinical variables and the reported birth weights.There were no significant differences in mean birth weights of babies born to control subjects or AgP patients. This was true whether all the births were considered or only those reported1 or 2 years before periodontal examination. For periodontally healthy controls, 13.2% of babies born to siblings of AgP patients and 12.8% of babies born to unrelated mothers weighed2,500 g, whereas 9.9% of those born to mothers with generalized AgP and 10.3% of those born to mothers with localized AgP weighed2,500 g.Because of the relative rarity of AgP in the population, and attendant difficulties in performing a prospective study of its association with pregnancy outcomes, we used a compromised approach using prospective data as well as weaker retrospective data assuming that disease onset was likely before the births. Our results, within the limitations of this approach, indicate no evidence that AgP in the mother predisposes low birth weights. AgP has many unique biologic characteristics that differentiate it from chronic forms of periodontal disease, and the possible lack of its association with birth weight may be another such characteristic.

This study compared faculty perceptions and expectations of dental students' abilities using virtual reality simulation (VRS) to those who did not use virtual reality simulation (non-VRS) in an operative dentistry preclinical course. A sixteen-item survey with a ten-point rating scale and three open-ended questions asked about students' abilities in ergonomics, confidence level, performance, preparation, and self-assessment. The surveys were administered three times to a small group of preclinical faculty members. First, faculty members (n=12, 92 percent response rate) gave their perceptions of non-VRS students' abilities at the end of their traditional course. Secondly, faculty members (n=13, 100 percent response rate) gave their expectations of the next incoming class's abilities (VRS students) prior to the start of the course with traditional and VRS components. Finally, faculty members (n=13, 100 percent response rate) gave their perceptions of VRS students' abilities after completion of the course. A Tukey's test for multiple comparisons measured significance among survey items. Faculty perceptions of VRS students' abilities were higher than for non-VRS students for most abilities examined. However, the faculty members' expectations of VRS training were higher than their perceptions of the students' abilities after VRS training for most abilities examined. Since ergonomic development and technical performance were positively impacted by VRS training, these results support the use of VRS in a preclinical dental curriculum.

Sahingur SE, Xia X-J, Gunsolley J, Schenkein HA, Genco RJ, De Nardin E. Single nucleotide polymorphisms of pattern recognition receptors and chronic periodontitis. J Periodont Res 2011; 46: 184–192. © 2010 John Wiley & Sons A/S Background and Objective: Periodontitis is a multifactorial disease influenced partly by genetics. Activation of pattern recognition receptors (PRRs) can lead to the up-regulation of inflammatory pathways, resulting in periodontal tissue destruction. Hence, functional polymorphisms located in PRRs can explain differences in host susceptibility to periodontitis. This study investigated single nucleotide polymorphisms of PRRs including toll-like receptor (TLR)2 (G2408A), TLR4 (A896G), TLR9 (T1486C), TLR9 (T1237C) and CD14 (C260T) in patients with chronic periodontitis and in periodontally healthy subjects. Methods: One-hundred and fourteen patients with chronic periodontitis and 77 periodontally healthy subjects were genotyped using TaqMan® allelic discrimination assays. Fisher’s exact test and chi-square analyses were performed to compare genotype and allele frequencies. Results: The frequency of subjects with the CC genotype of CD14 (C260T) (24.6% in the chronic periodontitis group vs. 13% in the periodontally healthy group) and those expressing the T allele of CD14 (C260T) (CT and TT) (75.4% in the chronic periodontitis group vs. 87% in the periodontally healthy group) was statistically different among groups (p = 0.04). Homozygocity for the C allele of the CD14 (C260T) polymorphism (CC) was associated with a two--fold increased susceptibility to periodontitis (p = 0.04; odds ratio, 2.49; 95% confidence interval, 1.06–6.26). Individuals with the CC genotype of TLR9 (T1486C) (14.9% in the chronic periodontitis group vs. 28.6% in the periodontally healthy group) and those expressing the T allele of TLR9 (T1486C) (CT and TT) (85.1% in the chronic periodontitis group vs. 71.4% in the periodontally healthy group) were also significantly differently distributed between groups without adjustment (p = 0.03). Further analysis of nonsmokers revealed a significant difference in the distribution of genotypes between groups for TLR9 (T1486C; p = 0.017) and CD14 (C260T; p = 0.03), polymorphisms again without adjustment. Conclusion: The CC genotype of CD14 (C260T) is related to susceptibility to chronic periodontitis in Caucasians. In addition, differences observed in the distribution of TLR9 (T1486C) genotypes between groups warrant further investigation.

The goal of this study is to determine whether HIV infection or high-risk behaviors associated with HIV infection are related to alveolar bone loss in a sample of subjects screened at a dental school clinic.Subjects were included in this study (N = 355) if they were HIV positive or had high-risk behaviors associated with HIV infection as identified by health risk behavior screening questionnaire. Bone loss measurements were obtained from radiographs. Both bivariate relationships and multivariate relationships between alveolar bone loss and three sets of variables were evaluated: high-risk behavior questions, demographic variables, and HIV infection.The following variables were found related to alveolar bone loss in bivariate relationships: age (Por = 0.0001); smoking (pack-years) (Por = 0.0001); race (Por = 0.002); gender (Por = 0.032); male-male sex (P0.001); diabetes (Por = 0.015); sharing of needles (Por = 0.02); and hepatitis C positive (Por = 0.05). In the multiple regression model, age, smoking, race, gender, and male-male sex remained significant. In both analyses, HIV-positive individuals had similar bone loss compared to those who were HIV negative.These results suggest that HIV infection is not related to alveolar bone loss in individuals with high-risk behaviors for HIV infection. These results also suggest that previously reported relationships between HIV infection and increased alveolar bone loss may be explained by other factors, such as smoking. Individuals in this study population with risk behaviors associated with HIV infection smoked at a high rate and, because of the smoking behavior, have a high rate of periodontal disease.

The purpose of this study was to compare the performance of students exposed to two different instructional modalities for dental anatomy wax carving: CAI (computer-assisted instruction) using DVD technology, or traditional laboratory instruction. Students' self-assessment scores were also compared to faculty scores, and students' perceptions of their teaching modality were analyzed. Seventy-three first-year dental students (response rate 81 percent) participated in this randomized single blind trial, in which faculty graders were blinded to student group assignment. There were no statistical differences, as determined by the Wilcoxon non-parametric test and a t-test, between the faculty grades on the wax carving from the two teaching methods the students experienced. The student self-assessments revealed higher mean grades (3.0 for the DVD-only group and 3.1 for the traditional group) than the faculty actual mean grades (2.2 for both the DVD-only group and the traditional group) by almost one grade level on a 4.0 grade scale. Similar percentages of students in the traditional group had either favorable or unfavorable perceptions of their learning experience, while more students in the DVD-only group reported favorable perceptions. Students from both groups said they wanted more faculty feedback in the course. Based on these objective and subjective data, merging CAI and traditional laboratory teaching may best enhance student learning needs.

Periodontitis develops in a time-dependent manner. Cross-sectional studies document one moment in time but fail to capture the progressive nature of disease. Radiographic measures of bone loss are relatively insensitive but are reliable markers of irreversible disease. Longitudinal studies are needed to identify biomarkers that can precede radiographic evidence of bone loss and, thus, mark the period prior to clinical evidence of irreversible disease. A longitudinal study of students susceptible to localized aggressive periodontitis (LAgP) was conducted to evaluate chemokines/cytokines found in saliva derived from periodontally healthy children who subsequently developed alveolar bone loss.Students were screened, sampled for Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans [Aa]), and divided into a cohort of Aa+ and Aa- students. Ninety-six periodontally healthy Aa+ and Aa- students were recalled every 6 to 9 months following screening. Examinations, saliva collections, and radiographs were performed. After seven students developed bone loss, the levels of 21 cytokines were assessed and matched to saliva from seven Aa+ and seven Aa- students who remained healthy foror =1 year. Subsequently, saliva from an additional 27 students who remained healthy was analyzed.Nineteen cytokines were not detected or were detected at low levels. Macrophage inflammatory protein (MIP)-1alpha was elevated 50-fold in seven Aa+ students who developed disease 6 to 9 months prior to radiographic detection of bone loss compared to levels in 21 Aa+ and 20 Aa- students who remained healthy (P0.001). Interleukin (IL)-1beta was also elevated (P = 0.01). MIP-1alpha had a specificity of 96.8% and a sensitivity of 100%, whereas IL-1beta showed 90.3% specificity and 85.7% sensitivity relative to bone loss. MIP-1alpha levels were also related to increasing probing depth and the number of pockets6 mm.The superior sensitivity and specificity of MIP-1alpha, which correlated well with probing depths and the onset of bone loss, suggested that it could be used as an early biomarker for LAgP.

Low-calorie diets are commonplace for reducing body weight. However, no information is available on the effects of a reduced-calorie diet on periodontal inflammation and disease. The purpose of this study was to evaluate the clinical effects of a long-term calorie-restriction (CR) diet on periodontitis in an animal model of periodontitis.Periodontitis was induced in 55 young, healthy, adult rhesus monkeys (Macaca mulatta) by tying 2.0 silk ligatures at the gingival margins of maxillary premolar/molar teeth. Animals on a CR diet (30% CR; N = 23) were compared to ad libitum diet controls (N = 32). Clinical measures, including the plaque index (PI), probing depth (PD), clinical attachment level (CAL), modified gingival index (GI), and bleeding on probing (BOP) were recorded at baseline and 1, 2, and 3 months after ligature placement.Significant effects of CR were observed on the development of inflammation and the progression of periodontal destruction in this model. Compared to controls, CR resulted in a significant reduction in ligature-induced GI (P0.0001), BOP (P0.0015), PD (P0.0016), and CAL (P0.0038). Periodontal destruction, as measured by CAL, progressed significantly more slowly in the CR animals than in the controls (P0.001).These clinical findings are consistent with available evidence that CR has anti-inflammatory effects. Moreover, these experimental findings are the first observations, to the best of our knowledge, that CR dampens the inflammatory response and reduces active periodontal breakdown associated with an acute microbial challenge.

Smoking increases the risk for periodontal disease and reduces the healing response. We examined the antimicrobial and clinical effects of scaling and root planing (SRP) with and without minocycline HCl 1 mg microspheres (MM) relative to smoking status in subjects with periodontitis.A total of 127 subjects (46 never smokers, 44 former smokers, and 37 current smokers) with moderate to advanced periodontitis were randomized to receive MM + SRP (N = 62) or SRP alone (N = 65). Subgingival plaque samples collected at baseline and day 30 were examined for the presence of 40 periodontal bacteria by DNA probe analysis.MM + SRP reduced red-complex bacteria (RCB) numbers and proportions to a greater extent than SRP alone, irrespective of smoking status. RCB numbers were not reduced by SRP in current smokers. The difference in the reduction in numbers of RCB by SRP relative to MM + SRP in current smokers was statistically significant (P0.05). Numbers and proportions of orange complex bacteria (OCB) were reduced in all groups treated with MM + SRP. Proportions of OCB increased in current smokers treated with SRP alone. In current smokers, MM + SRP significantly reduced probing depth (PD), increased clinical attachment level (CAL), and reduced bleeding on probing (BOP) to a greater extent than SRP alone (P0.05).SRP alone was ineffective at reducing numbers or proportions of RCB or OCB in current smokers, whereas MM + SRP significantly reduced both. MM + SRP also improved PD, BOP, and CAL to a greater extent than SRP alone independent of smoking status.

Background: The objective of this trial was to measure the antimicrobial effects of a minocycline HCl microsphere (MM) local drug-delivery system when used as an adjunct to scaling and root planing (SRP). DNA probe analysis for 40 bacteria was used to evaluate the oral bacteria of 127 subjects with moderate to advanced chronic periodontitis. Methods: Subjects were randomly assigned to either SRP alone (N = 65) or MM + SRP (N = 62). The primary endpoints of this study were changes in numbers and proportions of the red-complex bacteria (RCB) and the sum of Porphyromonas gingivalis, Tannerella forsythia (formally T. forsythensis), and Treponema denticola relative to 40 oral bacteria at each test site from baseline to day 30. Numbers of RCB from the five test sites were averaged to provide a value for each subject. Results: MM + SRP reduced the proportion of RCB by 6.49% and the numbers by 9.4 · 10 5 . The reduction in RCB proportions and numbers by SRP alone (5.03% and 5.1 · 10 5 , respectively) was significantly less. In addition, MM + SRP reduced probing depth by 1.38 mm (compared to 1.01 mm by SRP alone), bleeding on probing was reduced by 25.2% (compared to 13.8% by SRP alone), and a clinical attachment level gain of 1.16 mm (compared to 0.80 mm by SRP alone) was achieved. Conclusion: These observations support the hypothesis that RCBs are responsible for periodontal disease and that local antimicrobial therapy using MM + SRP effectively reduces numbers of RCBs and their proportions to a greater extent than SRP alone. J Periodontol 2007;78:1568-1579.

The purpose of this study was to compare students' in-school academic performance with their scores on the North East Regional Board (NERB) of Dental Examiners' Dental Simulated Clinical Examination (DSCE; written) and the written examination given by the National Board of Dental Examiners, Part II (NBDE Part II). A second purpose was to evaluate whether requiring the DSCE in addition to the NBDE II is of benefit in assessing the qualifications of candidates for licensure. Results on the first attempt at passing the two examinations were compared for 836 graduates (1994-2002) of one dental school. Mean scores on the examinations and mean grade point average (GPA) of those who passed the two examinations did not differ. Mean GPAs of those who failed the two examinations also were not significantly different. Scores on the two exams and GPA significantly correlated with each other. Correlation coefficients were higher between GPA and scores on the NBDE II than between GPA and scores on the DSCE. The failure rates on first attempts were 6 percent on the DSCE and 7 percent on the NBDE II. The results of this study suggest that the DSCE does not materially assist in the licensure decision for candidates who passed the NBDE Part II, as the results on the two exams are very similar.

Many clinical studies have demonstrated that guided tissue regeneration (GTR) is a successful treatment modality of periodontal reconstructive surgery and it has become an accepted procedure in most periodontal practices.The purpose of this structured review was to assess the efficacy of guided tissue regeneration (GTR) procedures in patients with periodontal osseous defects compared with surgical controls on clinical, radiographic, adverse, and patient-centered outcomes. It extends the scope of previous GTR systematic reviews, which were limited to randomized controlled studies, by the scope of outcome measures examined, and the duration of the study.In patients with periodontal osseous defects, what is the effect of physical barriers compared with surgical controls on clinical, radiographic, adverse, and patient-centered outcomes?An electronic search of the Cochrane Oral Health Group Trials Register and MEDLINE databases was performed. Manual searching of journals included Journal of Clinical Periodontology, Journal of Periodontology, and Journal of Periodontal Research up to January 2002. This manual search also included review of relevant bibliographies. Two manufacturers of GTR devices were contacted regarding unpublished data.Studies were selected for review if the evidence level was 3B (cohort) or above, at least 6 months duration, and compared a test GTR intervention with a surgical control.Studies with experimental design problems; histologic or microbiological investigations; or those with outcome measurements, study populations, or study duration not consistent with the inclusion criteria were excluded. Primary outcome measures for intrabony defects were: clinical attachment level (CAL) gain, probing depth reduction (PD), gingival recession (REC) reduction; for furcation defects: vertical probing attachment level (VPAL) gain, vertical probing depth reduction (VPD), horizontal probing depth reduction (HPD), horizontal open probing attachment level gain (HOPA), and vertical open probing attachment level gain (VOPA). Meta-analysis was performed to compare GTR procedures to other surgical treatments and to examine the resulting clinical outcomes.1. For the primary outcome variables, in both intrabony-defect and furcation-defect studies, GTR was favored over open flap debridement (OFD) therapies (P0.0001). 2. No differences were detected among barrier types, but barrier types could explain some heterogeneity in the results. 3. Augmentation of the GTR barrier with a particulate graft enhanced VPD (P0.05), VPAL, and HOPA, but none of the intrabony outcomes.Overall, GTR is consistently more effective than OFD in the gain of clinical attachment and probing depth reduction in the treatment of intrabony and furcation defects.

A variety of soft tissue augmentation procedures directed at root coverage have been documented in the literature utilizing autogenous or allogenic soft tissue grafting or guided tissue regeneration (GTR).The purpose of this systematic review was to assess the literature regarding the efficacies of various surgical gingival augmentation procedures relative to clinical and patient-oriented outcomes.What is the effect of surgical therapy for root coverage in patients with gingival recession compared with other treatment modalities or baseline values?PubMed and the Cochrane Oral Health Group Trials Register were searched to identify human studies in English investigating the therapeutic use of a soft tissue surgical procedure to treat gingival recession. Searches were performed for articles published by April 2002.Initial screening of identified abstracts accepted all studies evaluating surgical intervention of gingival recession. Independent review by 2 reviewers evaluated full-text reports regarding study characteristics. Only those studies determined to be randomized clinical trials (RCTs) were included in the final analysis. DATA ANALYSIS AND COLLECTION: Outcome measures included changes in root coverage, clinical attachment levels (CAL), probing depth (PD), and width of keratinized tissue (KT). The only data suitable for meta-analysis were comparisons of the efficacy of connective tissue grafts with GTR.1. Thirty-two articles (total study population: 687) met the criteria for RCTs: 11 (population: 286) related to various autogenous soft tissue augmentation procedures; 18 (population: 360) to GTR; and 3 (population: 41) to allogenic soft tissue augmentation. 2. Meta-analysis identified greater gains in both root coverage and keratinized tissue width for connective tissue graft procedures compared to GTR. 3. No other data were compatible with meta-analysis.1. Soft tissue augmentation procedures are effective means of obtaining root coverage. 2. Connective grafting techniques appear to have an advantage over GTR. 3. There is a need for further efficacy studies and for investigation of these procedures relative to patient-oriented outcomes such as esthetics, root sensitivity, and postoperative morbidities.

Previous surgical crown lengthening studies have investigated positional changes of the free gingival margin but not the biological width. Histological studies utilizing animal models have shown that postoperative crestal resorption allowed reestablishment of the biological width. However, very little work has been done in humans. Therefore, the purpose of this study was to evaluate the positional changes of the periodontal tissues, particularly the biological width, following surgical crown lengthening in human subjects.Twenty-three (23) patients who needed surgical crown lengthening to gain retention necessary for prosthetic treatment and/or to access caries, tooth fracture, or previous prosthetic margins entered the study. The following parameters were obtained from line angles of treated teeth (teeth requiring surgical crown lengthening) and adjacent teeth with adjacent and non-adjacent sites: plaque and gingival indexes, free gingival margin, probing depth, attachment level, bone level, direct bone level, and biological width. During surgery, the bone level was reduced based on the future prosthetic margin and predetermined biological width; flaps were placed at the bony crest. Patients were examined at baseline and at 3 and 6 months postoperatively.Eighteen patients completed the study. Overall, the amount of bone resected was 1 to 5 mm. At 90% of treated sites,or = 3 mm of bone was removed. At 3 months, the apical displacement of the free gingival margin at non-adjacent, adjacent, and treated sites was 2.46 +/- 0.25 mm, 2.68 +/- 0.20 mm, and 3.07 +/- 0.16 mm, respectively. There was no significant change in the position of the free gingival margin from 3 to 6 months. The biological width at all sites was smaller at 3 and 6 months compared to baseline (P0.05) except for the treated sites, which were not significantly different from baseline at 6 months.During surgical crown lengthening, the bone level was lowered for placement of the prosthetic margin and reestablishment of the biological width. The biological width, at treated sites, was reestablished to its original vertical dimension by 6 months. In addition, a consistent 3 mm gain of coronal tooth structure was observed at the 3- and 6-month examinations.

The purpose of this report is to compare outcomes on the North East Regional Board of Dental Examiners (NERB) clinical examination to selected measures of academic performance in one U.S. dental school. The data came from results of the spring 2001 NERB examination at that school. Five measures of academic performance--number of Class II amalgam restorations completed, number of Class III/IV composite restorations completed, fixed prosthodontic units performed, fourth-year class rank, and GPA-were compared between those who passed and those who failed NERB9s restorative exercise (RESTOR) and provisional fixed partial denture exercise (SIM). Analyses could not confirm a positive relationship between the school performance measures and the NERB outcome of passing RESTOR on the first attempt. On the other hand, those who passed SIM on the first attempt had, on the average, performed more amalgams, composites, and fixed prosthodontic units as students than those who failed; they also had, on average, better class rank and higher GPA. Therefore, only performance on SIM related to performance in school. However, both RESTOR and SIM had a similar number of failures from the top as well as the bottom portions of the class. These preliminary data from one dental school class raise questions about the validity of the NERB clinical examination for licensure decisions.

A major reason for the success of modern dental implant systems has been the development of implant designs that enhance direct bone-implant interface. Surface roughness has been a factor in this success and different systems have utilized very different implant surface roughness. The major purpose of this study was to evaluate 2 similar implants with different surface roughness characteristics.Two similarly designed, screw-type, commercially pure titanium implants, one dual acid-etched (DAE) and the other machined-surfaced (MS), were compared in this prospective, randomized-controlled, multi-center study, in which a total of 97 patients were enrolled at a private dental practice or a university dental clinic. Both implant types were placed in each patient using a 2-stage approach with a conventional 4- to 6-month healing period. Implants supported fixed prostheses, hybrid prostheses, and overdentures as dictated by the individual patient's need. All of the cases were followed using clinical and radiographic examinations. Criteria of success were the absence of peri-implant radiolucency, mobility, and persistent signs or symptoms of pain or infection.Of the 432 implants (247 dual acid-etched, 185 machined-surfaced), 36 implants (12 dual acid-etched and 24 machined-surfaced) have failed. The pre-loading integration success rate of the dual acid-etched implants (95.0%) was statistically higher (P0.01) than the success rate of the machined-surfaced implants (86.7%). At 36 months, the cumulative success rates (CSR) are 95.0% for the dual acid-etched implants and 86.7% for the machined-surfaced implants.The difference in success rates is most likely attributed to the acid-etched surface characteristics. The greatest performance difference is observed in the conditions of poor quality or soft bone where the 3-year post-loading CSR are 96.8% (dual acid-etched) and 84.8% (machined-surfaced).

The use of guided tissue regeneration (GTR) has become an effective procedure for the treatment of gingival recession. No reports exist on the use of a bioabsorbable membrane in combination with a demineralized freeze-dried bone allograft (DFDBA) for the treatment of these defects.Fourteen (14) patients with 17 recession defects were included in this clinical study. Each patient had at least 1 tooth with 3 mm or greater marginal tissue recession on the facial surface as measured from the cemento-enamel junction (CEJ). Each patient was treated by GTR using a bioabsorbable membrane. When the first patient presented for inclusion in the study, a coin was flipped to determine if the tooth being treated would be a test tooth (DFDBA) or a control tooth (no DFDBA). Each subsequent patient was alternated between test and control. Immediately prior to the surgical procedure, measurements were made which included recession depth, recession width at the widest point, probing depth, amount of keratinized tissue, and marginal tissue thickness. Local anesthesia was administered, and a measurement from the CEJ to the bone crest was made by sounding through the attachment.The mean initial recession for all defects was 3.35 mm (SD +/- 0.49) and at 6 months postsurgery, mean recession was 0.47 mm (SD +/0.62). This correlated to 86% root coverage for both treatments. For all defects treated, there was a statistically significant increase in keratinized tissue (mean 0.88 mm) and tissue thickness (mean 0.47 mm) and a significant decrease in probing bone level (mean 0.76 mm). No statistically significant differences were observed between groups for any parameter.Although only 14 subjects with 17 defects were included in this study, the results suggest that the treatment of human gingival recession with a bioabsorbable membrane with or without the use of DFDBA results in significant root coverage, and slight, but significant improvements in keratinized tissue, tissue thickness, and bone level. The greatest limitation of the study was its lack of statistical power. Twenty-two (22) subjects would have been required for the results of the study to show equivalence between groups.

Background: A few previous studies have suggested that risk for adult periodontitis (AP) has a genetic (heritable) component. We estimated genetic and environmental variances and heritability for gingivitis and adult periodontitis using data from twins reared together. Methods: One hundred seventeen (117) pairs of adult twins (64 monozygotic [MZ] and 53 dizygotic [DZ] pairs) were recruited. Probing depth (PD), attachment loss (AL), plaque, and gingivitis (GI) were assessed on all teeth by two examiners. Measurements were averaged over all sites, teeth, and examiners. Extent of disease in subjects was defined at four thresholds: the percentage of teeth with AL ≥2, AL ≥3, PD ≥4, or PD ≥5 mm. Genetic and environmental variances and heritability were estimated using path models with maximum likelihood estimation techniques. Results: MZ twins were more similar than DZ twins for all clinical measures. Statistically significant genetic variance was found for both the severity and extent of disease. AP was estimated to have approximately 50% heritability, which was unaltered following adjustments for behavioral variables including smoking. In contrast, while MZ twins were also more similar than DZ twins for gingivitis scores, there was no evidence of heritability for gingivitis after behavioral covariates such as utilization of dental care and smoking were incorporated into the analyses. Conclusions: These results confirm previous studies and indicate that approximately half of the variance in disease in the population is attributed to genetic variance. The basis for the heritability of periodontitis appears to be biological and not behavioral in nature. J Periodontol 2000;71:1699-1707.

The present studies evaluated the efficacy of a controlled-release biodegradable chlorhexidine (CHX) (2.5 mg) chip when used as an adjunct to scaling and root planing on reducing probing depth (PD) and improving clinical attachment level (CAL) in adult periodontitis. Two double-blind, randomized, placebo-controlled multi-center clinical trials (5 centers each) were conducted; pooled data are reported from all 10 centers (447 patients). At baseline, following 1 hour of scaling and root planing (SRP) in patients free of supragingival calculus, the chip was placed in target sites with PD 5 to 8 mm which bled on probing. Chip placement was repeated at 3 and/or 6 months if PD remained > or = 5 mm. Study sites in active chip subjects received either CHX chip plus SRP or SRP alone (to maintain study blind). Sites in placebo chip subjects received either placebo chip plus SRP or SRP alone. Examinations were performed at baseline; 7 days; 6 weeks; and 3, 6, and 9 months. At 9 months significant reductions from baseline favoring the chlorhexidine chip compared with both control treatments were observed with respect to PD (chlorhexidine chip plus SRP, 0.95 +/- 0.05 mm; SRP alone, 0.65 +/- 0.05 mm, P < 0.001; placebo chip plus SRP, 0.69 +/- 0.05 mm, P < 0.001) and CAL (chlorhexidine chip plus SRP, 0.75 +/- 0.06 mm; SRP alone, 0.58 +/- 0.06 mm, P < 0.05; placebo chip plus SRP, 0.55 +/- 0.06 mm, P < 0.05). The proportion of patients who evidenced a PD reduction from baseline of 2 mm or more at 9 months was significantly greater in the chlorhexidine chip group (19%) compared with SRP controls (8%) (P < 0.05). Adverse effects were minor and transient toothache, including pain, tenderness, aching, throbbing, soreness, discomfort, or sensitivity was the only adverse effect that was higher in the chlorhexidine group as compared to placebo (P = 0.042). These data demonstrate that the adjunctive use of the chlorhexidine chip results in a significant reduction of PD when compared with both SRP alone or the adjunctive use of a placebo chip. These multi-center randomized control trials suggest that the chlorhexidine chip is a safe and effective adjunctive chemotherapy for the treatment of adult periodontitis.

The purpose of this study was to determine which treatment of a large osseous defect adjacent to an endosseous dental implant would produce the greatest regeneration of bone and degree of osseointegration: barrier membrane therapy plus demineralized freeze-dried bone allograft (DFDBA), membrane therapy alone, or no treatment. The current study histologically assessed changes in bone within the healed peri-implant osseous defect. In a split-mouth design, 6 implants were placed in edentulous mandibular ridges of 10 mongrel dogs after preparation of 6 cylindrical mid-crestal defects, 5 mm in depth, and 9.525 mm in diameter. An implant site was then prepared in the center of each defect to a depth of 5 mm beyond the apical extent of the defect. One mandibular quadrant received three commercially pure titanium (Ti) screw implants (3.75 x 10 mm), while the contralateral side received three hydroxyapatite (HA) coated root-form implants (3.3 x 10 mm). Consequently, the coronal 5 mm of each implant was surrounded by a circumferential defect approximately 3 mm wide and 5 mm deep. The three dental implants in each quadrant received either DFDBA (canine source) and an expanded polytetrafluoroethylene membrane (ePTFE), ePTFE membrane alone, or no treatment which served as the control. Clinically, the greatest increase in ridge height and width was seen with DFDBA/ePTFE. Histologically, statistically significant differences in defect osseointegration were seen between treatment groups (P0.0001: DFDBA/ePTFEePTFE alonecontrol). HA-coated implants had significantly greater osseointegration within the defect than Ti implants (P0.0001). Average trabeculation of newly formed bone in the defect after healing was significantly greater for HA-coated implants than for titanium (P0.0001), while the effect on trabeculation between treatments was not significantly different (P = 0.14). Finally, there were significantly less residual allograft particles in defect areas adjacent to HA-coated implants than Ti implants (P = 0.0355). The use of HA-coated implants in large size defects with DFDBA and ePTFE membranes produced significantly more osseointegration histologically than other treatment options and more than Ti implants with the same treatment combinations. The results of this study indicate that, although the implants appeared osseointegrated clinically after 4 months of healing, histologic data suggest that selection of both the implant type and the treatment modality is important in obtaining optimum osseointegration in large size defects.

High titers of serum IgG2 reactive with Actinobacillus actinomycetemcomitans are present in early-onset periodontitis (EOP) patients and it appears that anti-A. actinomycetemcomitans may be protective. Smoking is associated with increased periodontal disease severity in generalized early-onset periodontitis (G-EOP) patients, but is not associated with periodontal disease severity in patients with localized juvenile periodontitis (LJP). Furthermore, smoking is associated with reduced serum IgG2 levels in black patients with G-EOP but not in those with LJP. Based on this selective effect of smoking, we hypothesized that smoking would be associated with a reduction of specific IgG2 reactive with A. actinomycetemcomitans in black G-EOP patients but not black LJP patients. In addition, we examined IgG2 responses to carbohydrate antigens from non-periodontal pathogens including Haemophilus influenzae b oligosaccharide antigen (Hib) and the Streptococcus pneumoniae antigen phosphocholine (PC). Smoking status was assessed from serum cotinine levels, and IgG2 specific for A. actinomycetemcomitans, Hib, and PC was assessed by ELISA. Our study revealed that smoking was correlated with a dramatic reduction in serum IgG2 anti-A. actinomycetemcomitans in G-EOP smokers but not in LJP smokers. In contrast, anti-Hib IgG2 and anti-PC IgG2 were not affected in either G-EOP or LJP patients. In short, these results indicate that smoking is associated with a reduction in serum IgG2 anti-A. actinomycetemcomitans in black G-EOP subjects, but IgG2 reactive with other antigens may not be reduced in G-EOP smokers.

In previous studies we have demonstrated that serum IgG subclass concentrations are influenced by both race and periodontal disease diagnosis. Furthermore, we have shown that smoking habits modify the concentrations of some IgG subclasses in specific racial and diagnostic groups. In view of a large amount of data showing strong associations between immunoglobulin allotypes and IgG subclass concentrations we have investigated the effects of race, smoking and IgG allotype on IgG subclass concentration in a population of subjects with or without various forms of periodontitis. The results indicated that there are complex relationships between these factors in their effects on individual IgG subclass levels, and that effects unique to black or white subject groups, or to specific periodontal diagnostic groups and racial subgroups, were evident. In blacks with chronic adult periodontitis IgG1 was lower in smokers, while in generalized early-onset periodontitis patients IgG2 was lower in smokers. IgG4 was independently affected by gender (males higher), smoking (smokers lower) and GM23 (GM23 positive subjects higher), in black subjects only. In white subjects, complex relationships between smoking and allotypic markers were noted but no influence of periodontal diagnosis was found. White GM23 negative subjects who smoked had lower levels of IgG1 than GM23 positive subjects. White GM2 negative subjects who smoked had lower levels of IgG2, than did those who did not smoke. In contrast, smoking had no effect on IgG2 levels in GM2 positive subjects. Thus, in addition to immunoglobulin allotype, smoking is associated with IgG subclass concentrations; furthermore, in black subjects, periodontal diagnosis, gender and smoking all influence IgG subclass concentrations. These results demonstrate that genetic and environmental factors can interact to influence levels of individual subclasses.

The purpose of this study was to determine the clinical course of early onset periodontitis and to investigate factors which may influence its clinical course. For the past 15 years we have been conducting a study of families with early onset periodontitis, and have examined 142 localized juvenile periodontitis and 185 severe generalized early onset periodontitis patients. In order to study the clinical course of early onset periodontitis we recalled our subject population to determine their periodontal status. Forty (40) patients with localized early onset periodontitis (LJP) and 48 with generalized early onset periodontitis (SP) were re-examined. The time since the most recent visit for LJP patients was approximately 3 years and for SP patients almost 4 years. LJP patients who received periodontal therapy on the average gained periodontal attachment. In contrast, LJP patients who did not receive therapy lost periodontal attachment. SP patients lost periodontal attachment regardless of whether or not they had periodontal therapy. SP patients also lost an average of one tooth during the approximately 4 years of observation. LJP patients lost very few teeth with only 4 teeth being lost in 40 patients. The results of this study suggest that localized juvenile periodontitis is a stable disease in most individuals. In contrast, patients with severe generalized early onset periodontitis continued to lose both periodontal attachment and teeth.

Early-onset periodontitis (EOP) refers to a group of severe periodontal diseases with age of onset near puberty that are characterized by rapid destruction of the tissues supporting the teeth in otherwise healthy individuals. Mixed model segregation analyses of 100 families, ascertained through 104 probands with EOP, were carried out to test major locus and multifactorial hypotheses for the etiology of EOP. Heterogeneity tests were used to compare the parameter estimates and conclusions obtained in Black families from those from non-Black families. The data in these families confirmed that the often-reported female preponderance of EOP appears to be an ascertainment bias. The segregation analysis results were consistent with an autosomal major locus being sufficient to explain the family patterns of EOP in the entire dataset, and also in both the Black and non-Black subsets. A dominant mode of transmission was most likely, with penetrance of about 70%. Although the etiologic conclusions were the same for Black and non-Black families, there was significant heterogeneity in parameter estimates. In particular the Black allele frequency was 0.016 versus the non-Black frequency of 0.001.

Delmopinol, a 3-alkyl substituted N-hydroethyl morpholine, has shown potential as a mouthrinse for the management of dental plaque and treatment of gingivitis. Delmopinol has been shown to possess plaque inhibitory activity in several previous studies. The aims of this study were to: 1) compare the antiplaque, antigingivitis efficacy and safety of 0.1% and 0.2% delmopinol-containing mouthrinses (DMP) in a 2-week, randomized, parallel arm, vehicle controlled study; and 2) determine if a dose response antiplaque, antigingivitis effect could be found in this type of formulation. One hundred and thirty-three male subjects were randomly assigned to one of three groups, 0.1% DMP, 0.2% DMP, or vehicle control mouthrinses. At baseline all subjects received a clinical examination consisting of an intraoral soft tissue, plaque (Turesky modification of Quigley-Hein plaque index), and gingival index (modified gingival index) evaluations, and received a thorough oral prophylaxis. All subjects refrained from all forms of oral hygiene for the next 2 weeks, except for the use of the assigned mouthrinse. Subjects rinsed for 1 minute with their assigned mouthrinse twice daily under supervision for 2 weeks. Following 2 weeks of mouthrinse use, plaque and gingivitis scoring and soft tissue examinations were repeated. The results showed the mean plaque index at the 2-week examination was statistically related to the baseline value (P0.0003, ANOVA) and the concentration of DMP (P0.0001, ANOVA). In contrast, the gingivitis index was not related to the concentration of DMP (P0.05, ANOVA). No adverse effects were noted or reported during this clinical trial.

This study evaluated the effect of periodontal therapy on clinical and microbiological parameters in 23 subjects with severe generalized early onset periodontitis. Therapy consisted of oral hygiene instruction and root planing and scaling, followed 3 months later by open flap debridement. Subjects were monitored for both clinical measures and levels of Actinobacillus actinomycetemcomitans and Porphyromas gingivalis as identified by indirect immunofluoresence. Clinical and microbiological evaluations were done at the start of the study, 3 months after the completion of root planing and scaling and 3 months after open flap debridement. Mean probing depth was reduced by both root planing and scaling and open flap debridement and the level of reduction demonstrated by both phases of therapy was similar to reductions found in studies that utilized subjects with chronic adult periodontitis. In contrast, reductions in attachment level due to the two phases of therapy, demonstrated in previous studies of subjects with adult periodontitis were not found in the young adult subjects with severe periodontal disease utilized in this study. Levels of A. actinomycetemcomitans were not significantly affected by root planing and scaling, but were reduced by open flap debridement. P. gingivalis was virtually eliminated by root planing and scaling, demonstrating that the two bacterial types respond differently to periodontal therapy. These changes in microbiological parameters were similar to those found in studies of localized juvenile periodontitis subjects, where surgery or antibiotics have been shown to be necessary to reduce levels of A. actinomycetemcomitans.

A great deal of controversy has existed in the periodontal literature as to whether the site or the subject should be the unit of analysis. Using the site as the unit of analysis assumes that observations of sites within the same subject are independent and ignores between subject variation. The purpose of this report is to evaluate the influence that the unit of analysis has on estimating the number of necessary site specific bacterial samples from each subject. The number of bacterial samples per subject was defined as the number of samples that would insure a clinician at a 95% confidence level that, if the bacteria were present in a subject, it would be discovered. From two data sets in which 20 to 30 bacterial samples were taken from each subject and data generated from a simulation, appropriate within-subject sample size was determined. In one data set the presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Bacteroides forsythus, and Prevotella intermedia was determined by indirect immunofluorescence. In the other data set the presence of A. actinomycetemcomitans, P. gingivalis, and P. intermedia was determined using DNA probes. Results of this study demonstrate that there is a large between subject variation in site specific bacterial prevalence, as indicated by an elevated intraclass correlation. Simulated data in this report demonstrated that the number of necessary bacterial samples per subject increased with increasing values of intraclass correlation. The number of necessary within subject samples also increased with decreasing prevalence rate. For A. actinomycetemcomitans, which had a low prevalence rate (0.11 to 0.18), the number of necessary samples per subject was very high (31 to 35).(ABSTRACT TRUNCATED AT 250 WORDS)

In order to appropriately carry out a longitudinal assessment of periodontal attachment loss in individuals with untreated periodontitis, reliable criteria for determining "real" changes in attachment level (AL) are required. In the present study, 25 subjects were to be examined every 2 months for up to 2 years to determine changes in AL and to relate clinical and laboratory criteria to such changes. Trained examiners for the study underwent calibration trials to determine inter-examiner and intra-examiner reliability both before the study and at intervals during the study. It was found that AL measurements were in agreement within 2 mm more than 95% of the time. The calibration trials provided an estimate of the error in attachment loss measurements, since no "real" attachment loss had occurred. From estimates of measurement error, the probability of false positive changes were determined. It was found that acceptable false positive rates (less than 5%) could be achieved if 2 examiners each detected 3 mm change at a given site or if 2 examiners each detected 2 mm change at a site and verified that this change persisted at a subsequent examination. The results of the longitudinal trial were then compared to the probability estimates calculated from the calibration trials. It was found that probabilities of AL changes detected during the longitudinal trial for less stringent conditions than described above (e.g., single examiner, 2 examiners unconfirmed) were similar to to previously estimated false positive rates.(ABSTRACT TRUNCATED AT 250 WORDS)

Higher levels of serum antibody reactive with Actinobacillus actinomycetemcomitans strain Y4 (AAY4) have been demonstrated in localized juvenile periodontitis than in other forms of periodontal diseases. However, in studies which reported the racial distribution of the clinical groups, a predominantly black juvenile periodontitis population has been compared with a non-periodontitis control population that was predominantly white. The purpose of this study was to determine the effect of race (black or white) on antibody reactivity to AAY4 for subjects with clinical diagnoses of adult periodontitis (AP), non-periodontitis (NP), juvenile periodontitis (JP) and severe generalized periodontitis in young adults (SP). A radioimmunoassay (RIA) was utilized to detect and quantitate antibody to AAY4. Within clinical groups of NP, JP and SP a higher prevalence of seropositive black subjects than white subjects was found. The association between a high prevalence of positive antibody responses to AAY4 in JP subjects compared to NP subjects still exists, but was reduced compared to previous reports. White non-periodontitis subjects, used as control subjects in previous reports, were found to have a significantly lower frequency of seropositivity to AAY4 than black non-periodontitis subjects. This relationship held whether the periodontatly healthy subject was ascertained from a family with a JP or SP family member or was ascertained solely on the basis of a diagnosis of non-periodontitis. The difference in the prevalence of seropositivity to AAY4 between JP and SP subjects was entirely due to the racial composition of the two groups, as nearly half the SP subjects were white compared with only 15% of the JP subjects. Thus, antibody reactivity to AAY4 was found to be related to both clinical diagnosis and race.

Clinical trials for anti-gingivitis and anti-plaque agents commonly use the mean of Silness and Loe plaque indices and Loe and Silness gingival indices as response variables. The aim of this report is to determine if data from anti-plaque and anti-gingivitis clinical trials using Silness and Loe plaque indices and Loe and Silness gingival indices satisfy conditions necessary for the use of the univariate or multivariate approach to repeated measures. These conditions are multivariate normality, homogeneity of variance-covariance matrices, and for the univariate approach, a type-H variance-covariance matrix. Data from 5 separate clinical trials representing a wide range in sample size, pretreatment mean gingival and plaque indices and treatment effects were used to test these conditions. Either the univariate or multivariate approach to repeated measures was found to be appropriate for both responses of the 5 clinical trials. Thus, means of Silness & Loe and Loe and Silness gingival indices meet the necessary conditions for use of either the univariate and/or multivariate approach to repeated measures. However, significant time-treatment interactions are a common occurrence in these types of clinical trials and must be evaluated carefully. The analyses in this study were carried out using SAS. Other mainframe statistical software packages and many micro-computer statistical software packages have routines to analyze repeated measures experiments with analysis of variance methods. However, some of the packages may omit the multivariate approach to repeated measures or may not include interactions between within-subject and between-subject effects. These packages should be used with caution.

Between 1970 and 1986, 1651 biopsy specimens from the oral cavity or lips with a diagnosis of epithelial dysplasia were accessioned by the Medical College of Virginia Oral Pathology Diagnostic Service (Richmond, VA). Of the four histologic grades of epithelial dysplasia (focal mild, mild, moderate, and severe), most of the cases were diagnosed as mild (54.1%) and the fewest (8.1%) were in the severe category. The overall mean age at time of diagnosis was 56.7 years. A predilection for occurrence in males was confirmed, but a lower than expected incidence in blacks was noted. The most common anatomic sites were the buccal mucosa, palate, and floor of mouth. The anatomic areas which were most likely to have a severe epithelial dysplasia were the ventral surface of the tongue and the lip. Patients with dysplasias in more than one site had a slightly higher probability of being diagnosed as either moderate or severe. The cases associated with lichen planus usually were found on the buccal mucosa and demonstrated a shift toward a milder degree of dysplasia.

Attachment level or pocket depth measurements are used to detect change in periodontal attachment. However, measurement error limits their usefulness for this purpose. The aims of this study are twofold. The first aim was to test the assumption, used in previous reports of measurement error, that attachment level measurements are normally distributed. The second aim was to estimate error rates encountered when assessing periodontal attachment level change with attachment level or pocket depth measurements. Two simulation methods are compared in their ability to reproduce the distribution of differences in replicated measurements. A simulation method based on a normal distribution was not able to reproduce the actual distribution of differences between replicate measurements. In contrast simulations based on resampling recreated the distribution of differences in replicated attachment level measurements. Due to the inability of simulations based on the normal distribution to reproduce the distribution of differences in replicated measurements, simulations based on the resampling procedure were used to estimate error rates. Determining change in attachment level or pocket depth by either single or paired measurements resulted in low Type I error rates for both single and paired measurements. For single measurements of attachment level, the Type I error rate was 0.0074 for a 3-mm change. Paired measurements of attachment level had a Type I error rate of 0.0014 for a 3-mm change. However, false-positive rates were found to be much higher. For single measurements of attachment level, the false-positive rate was 0.32 for a 3-mm change.(ABSTRACT TRUNCATED AT 250 WORDS)

Osteoclast development and growth were studied by determining the number of labelled nuclei in osteoclasts of different sizes (based on the number of nuclei per osteoclast, N/O) and the number of osteoclasts with labelled nuclei at various intervals after tritiated thymidine ([3H]TdR) injection in young rats. The osteoclast smears were made from the cellular periosteum of the proximal tibia. The frequency distribution of the N/O osteoclasts types in the smears had profiles similar to that of in situ osteoclasts in whole mounts of proximal tibia, which indicates that the osteoclast population of the smears was representative of that on the bone surface. A vast majority of the osteoclasts had a 1–6 N/O, and a number of the cells had as many as 26 or more nuclei. Furthermore, profiles of N/O frequency distributions were similar over the course of the study. Nuclei with [3H]TdR label were initially observed in osteoclasts between 4 and 12 hr after isotope injection. However, fusion of labelled nuclei to osteoclasts continued for at least 150 hr. In general, the labelled osteoclasts exhibited a significantly larger number of nuclei than the unlabelled osteoclasts. The probability of an osteoclast incorporating one or more labelled nuclei increased with time after injection and with an increase in N/O. Labelling intensity decreased with time post injection and with an increase in N/O. The data suggest that turnover of nuclei is more rapid in osteoclasts with high N/O values.

One hundred eight patients with a histologically confirmed diagnosis of epithelial dysplasia of the oral cavity and a prior history of smokeless tobacco (ST) usage were identified. The mean age at time of diagnosis for female patients was almost a decade later than for male patients (63.6 versus 51.2 years). In addition, women were more likely (P = 0.02) to have moderate or severe epithelial dysplasia than men. The two most common locations (buccal mucosa/vestibule and alveolar ridge/gingiva) accounted for 82.4% of all cases. In the 44 cases which specified both ST placement and biopsy site, 90.9% demonstrated epithelial dysplasia at the location used by the patient for holding the ST. When evaluating the histologic severity of epithelial dysplasia, a trend (P = 0.02) toward focal mild or mild was noted among ST users as compared to nonusers. No difference was found in the histologic grade of the lesions associated with either snuff or chewing tobacco.