The OHStat Guidelines for Reporting Observational Studies and Clinical Trials in Oral Health Research: Manuscript Checklist.

Adequate and transparent reporting is necessary for critically appraising published research. Yet, ample evidence suggests that the design, conduct, analysis, interpretation, and reporting of oral health research could be greatly improved. Accordingly, the Task Force on Design and Analysis in Oral Health Research-statisticians and trialists from academia and industry-identified the minimum information needed to report and evaluate observational studies and clinical trials in oral health: the OHStat Guidelines. Drafts were circulated to the editors of 85 oral health journals and to Task Force members and sponsors and discussed at a December 2020 workshop attended by 49 researchers. The guidelines were subsequently revised by the Task Force's writing group. The guidelines draw heavily from the Consolidated Standards for Reporting Trials (CONSORT), Strengthening the Reporting of Observational Studies in Epidemiology (STROBE), and CONSORT harms guidelines and incorporate the SAMPL guidelines for reporting statistics, the CLIP principles for documenting images, and the GRADE indicating the quality of evidence. The guidelines also recommend reporting estimates in clinically meaningful units using confidence intervals, rather than relying on P values. In addition, OHStat introduces 7 new guidelines that concern the text itself, such as checking the congruence between abstract and text, structuring the discussion, and listing conclusions to make them more specific. OHStat does not replace other reporting guidelines; it incorporates those most relevant to dental research into a single document. Manuscripts using the OHStat guidelines will provide more information specific to oral health research.

The OHStat Guidelines for Reporting Observational Studies and Clinical Trials in Oral Health Research: Explanation and Elaboration.

Adequate and transparent reporting is necessary for critically appraising research. Yet, evidence suggests that the design, conduct, analysis, interpretation, and reporting of oral health research could be greatly improved. Accordingly, the Task Force on Design and Analysis in Oral Health Research-statisticians and trialists from academia and industry-empaneled a group of authors to develop methodological and statistical reporting guidelines identifying the minimum information needed to document and evaluate observational studies and clinical trials in oral health: the OHstat Guidelines. Drafts were circulated to the editors of 85 oral health journals and to Task Force members and sponsors and discussed at a December 2020 workshop attended by 49 researchers. The final version was subsequently approved by the Task Force in September 2021, submitted for journal review in 2022, and revised in 2023. The checklist consists of 48 guidelines: 5 for introductory information, 17 for methods, 13 for statistical analysis, 6 for results, and 7 for interpretation; 7 are specific to clinical trials. Each of these guidelines identifies relevant information, explains its importance, and often describes best practices. The checklist was published in multiple journals. The article was published simultaneously in JDR Clinical and Translational Research, the Journal of the American Dental Association, and the Journal of Oral and Maxillofacial Surgery. Completed checklists should accompany manuscripts submitted for publication to these and other oral health journals to help authors, journal editors, and reviewers verify that the manuscript provides the information necessary to adequately document and evaluate the research.

Periodontal Effects of the Reversible Dipeptidyl Peptidase 1 Inhibitor Brensocatib in Bronchiectasis.

AIMS: Brensocatib is a reversible inhibitor of dipeptidyl peptidase 1 (cathepsin C), in development to treat chronic non-cystic fibrosis bronchiectasis. The phase 2, randomized, placebo-controlled WILLOW trial (NCT03218917) was conducted to examine whether brensocatib reduced the incidence of pulmonary exacerbations. Brensocatib prolonged the time to the first exacerbation and led to fewer exacerbations than placebo. Because brensocatib potentially affects oral tissues due to its action on neutrophil-mediated inflammation, we analyzed periodontal outcomes in the trial participants. MATERIALS AND METHODS: Patients with bronchiectasis were randomized 1:1:1 to receive once-daily oral brensocatib 10 or 25 mg or placebo. Periodontal status was monitored throughout the 24-week trial in a prespecified safety analysis. Periodontal pocket depth (PPD) at screening, week 8, and week 24 was evaluated. Gingival inflammation was evaluated by a combination of assessing bleeding upon probing and monitoring the Löe-Silness Gingival Index on 3 facial surfaces and the mid-lingual surface. RESULTS: At week 24, mean ± SE PPD reductions were similar across treatment groups: -0.07 ± 0.007, -0.06 ± 0.007, and -0.15 ± 0.007 mm with brensocatib 10 mg, brensocatib 25 mg, and placebo, respectively. The distribution of changes in PPD and the number of patients with multiple increased PPD sites were similar across treatment groups at weeks 8 and 24. The frequencies of gingival index values were generally similar across treatment groups at each assessment. An increase in index values 0-1 and a decrease in index values 2-3 over time and at the end of the study were observed in all groups, indicating improved oral health. CONCLUSIONS: In patients with non-cystic fibrosis bronchiectasis, brensocatib 10 or 25 mg had an acceptable safety profile after 6 months' treatment, with no changes in periodontal status noted. Improvement in oral health at end of the study may be due to regular dental care during the trial and independent of brensocatib treatment. KNOWLEDGE TRANSFER STATEMENT: The results of this study suggest that 24 weeks of treatment with brensocatib does not affect periodontal disease progression. This information can be used by clinicians when considering treatment approaches for bronchiectasis and suggests that the use of brensocatib will not be limited by periodontal disease risks. Nevertheless, routine dental/periodontal care should be provided to patients irrespective of brensocatib treatment.

Unusual Findings in Trials Evaluating Adjuncts to Scaling and Root Planing: Reporting Quality (Part 2).

INTRODUCTION: On the topic of adjuncts to scaling and root planing (SRP), numerous randomized clinical trials (RCTs) were published by a single group of authors and frequently reported unusually large effect sizes. A meta-analysis in part 1 of this project failed to explain the causes for these unusual findings. We assessed the reporting quality and trial registration discrepancies to examine the possibility of replicating the work of this research group as well as the overall rigor of the research methodology. METHODS: This study was preregistered at the Open Science Framework (https://osf.io/4meyd/). The Scopus platform was utilized for the RCT search on SRP adjuncts in intrabony defects in patients with periodontitis as compared with SRP alone. The search analysis was limited from 2010 to 2017, and RCTs on SRP adjuncts published by a single research group were selected for screening and inclusion. RCT registration records were assessed for consistency. RESULTS: Out of 92 studies that were retrieved from Scopus and PubMed, 32 were included for quality assessment per the CONSORT guidelines (Consolidated Standards of Reporting Trials). Results showed that all RCTs were characterized by a low reporting quality. The majority of CONSORT items scored <50%, including critical items (randomization, registration, and blinding). When registration records were compared with published RCTs, several discrepancies were found. The per-protocol follow-up duration was compared against the study's initiation and termination dates. Only 38% of the RCTs presented a follow-up period within the initiation and termination dates. The remaining RCTs showed inconsistent follow-up in comparison with the initiation and termination dates. CONCLUSION: RCTs by this group were characterized by poor adherence to reporting quality guidelines. Crucial RCT elements, such as randomization, blinding, and primary outcomes, were not reported properly. RCT registration records revealed systematic inconsistencies when compared with RCT publication. Therefore, the unusually large effects reported by this group should be viewed with extreme caution. KNOWLEDGE TRANSFER STATEMENT: The included randomized clinical trials were characterized by poor adherence to reporting quality guidelines, missing information about important trial items, and discrepancies between the reports and trial registrations. This quality assessment should guide clinical research and show clinicians that they should be cautious when applying evidence in their clinical practice.

Unusual Findings in Trials Evaluating Adjuncts to Scaling and Root Planing: Meta-analysis (Part 1).

BACKGROUND: A number of studies in patients with periodontitis have compared scaling and root planning (SRP) combined with an adjunctive treatment to SRP alone. Within that literature, an array of studies with overlapping investigators has consistently yielded substantially greater effects of adjunctive treatments than had been previously noted. This report investigates discrepancies between that cluster of research and the most recent American Dental Association (ADA) systematic review. METHODS: This review was preregistered at https://osf.io/4meyd/. A search using the Scopus platform identified 32 articles published from 2010 to 2017 by investigators affiliated with the Government Dental College and Research Institute (GDCRI) in Bangalore, India. The primary outcome used in this meta-analysis was the change in clinical attachment level (CAL) after 6 mo. Effect sizes were estimated using Comprehensive Meta-Analysis software after categorizing agents into groups based on pharmacologic similarity. RESULTS: The search identified 32 studies encompassing 5 sets of adjunctive agents. Across the GDCRI studies, the CAL averaged 1.67 mm (95% confidence interval [CI]: 1.43-1.91 mm), substantially exceeding values reported in the ADA review (mean: 0.39 mm, 95% CI: 0.27-0.51 mm). For categories of studies in which comparable subgroup estimates were available, the evaluations yielded overlapping estimates of SRP alone, but CAL estimates were discrepant for both locally delivered antimicrobials (GDCRI studies: mean: 1.45 mm, 95% CI: 0.63-2.27 mm; ADA review: mean: 0.38 mm, 95% CI: 0.16 -0.60 mm) and systemic antibiotics (GDCRI studies: mean: 1.35 mm, 95% CI: 0.97-1.73 mm; ADA review: mean: 0.39 mm, 95% CI: 0.21-0.57 mm). CONCLUSION: In the literature on adjunctive agents supplementing SRP, findings from investigators linked to GDCRI stand out as having significantly more favorable estimated effects. Meanwhile, some agents studied by GDCRI-linked investigators have not been investigated by other researchers. In the absence of a clear explanation for discrepant results, it is recommended that unusually favorable reported effects of adjunctive agents be viewed with caution. KNOWLEDGE TRANSFER STATEMENT: The present meta-analysis observed an unusually large effect size of adjunctive agents to scaling and root planning in studies conducted by the same research group. These results were not consistent with trials on adjunctive agents and previous reports. As this research group has exclusively tested most of the agents, their results must be viewed with caution until other independent groups replicate the studies and reproduce the effect size.

Differential gender effects of a reduced-calorie diet on systemic inflammatory and immune parameters in nonhuman primates.

BACKGROUND AND OBJECTIVE: Dietary manipulation, including caloric restriction, has been shown to impact host response capabilities significantly, particularly in association with aging. This investigation compared systemic inflammatory and immune-response molecules in rhesus monkeys (Macaca mulatta). MATERIAL AND METHODS: Monkeys on continuous long-term calorie-restricted diets and a matched group of animals on a control ad libitum diet, were examined for systemic response profiles including the effects of both gender and aging. RESULTS: The results demonstrated that haptoglobin and alpha1-antiglycoprotein levels were elevated in the serum of male monkeys. Serum IgG responses to Campylobacter rectus, Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis were significantly elevated in female monkeys. While only the antibody to Fusobacterium nucleatum was significantly affected by the calorie-restricted diet in female monkeys, antibody levels to Prevotella intermedia, C. rectus and Treponema denticola demonstrated a similar trend. CONCLUSION: In this investigation, only certain serum antibody levels were influenced by the age of male animals, which was seemingly related to increasing clinical disease in this gender. More generally, analytes were modulated by gender and/or diet in this oral model system of mucosal microbial challenge.

Change in attachment level.

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)

Serum IgG and IgM levels to bacterial antigens in necrotizing ulcerative gingivitis.

Previous studies of the systemic antibody response in necrotizing ulcerative gingivitis (NUG) have elicited varying results. The purpose of this study was to determine the humoral response to site-specific isolates of microbiota associated with NUG. Sera from 21 active NUG subjects and 21 age-sex-race matched controls were assessed for IgG and IgM antibodies to 4 clinical isolates of Prevotella intermedia and 3 clinical isolates of Treponema species. P. intermedia and Treponema strains were isolated from active and inactive sites of NUG patients and gingivitis sites of controls. P. intermedia was also isolated from noninflamed sites of the controls. IgG and IgM serum levels to these 7 bacteria were measured by ELISA. Compared to control subjects, the NUG sera exhibited significantly lower IgG and IgM levels to all 4 isolates of P. intermedia (P < or = 0.001). It was also noted that sera from NUG subjects had elevated IgM levels to all 3 spirochete isolates but significantly higher only to the spirochete isolated from a gingivitis site of a control subject (P < or = 0.005). The data suggest that failure to mount a substantial antibody response to P. intermedia may be associated with onset of disease activity in NUG. However, the assumed lack of "biological significance" between differences in antibody responses measured indicates the relationship is weak or nonexistent. It also appears that antibody response to spirochetes is not associated with onset of NUG.

Equivalence and superiority testing in regeneration clinical trials.

The purpose of this report is to investigate sample size requirements for both equivalence and superiority studies investigating products used in regeneration. The goal of a superiority clinical trial is to determine if a new therapy is superior to an established therapy or placebo. In contrast to superiority trials, equivalence trials are used to determine if a new product has similar therapeutic properties to an established product. The sample sizes for the two different types of clinical trials were based on the following assumptions: an alpha of 0.05, a power of 0.80, a 2 group parallel arm study, and equal variances and sample sizes for both groups. Separate sample size calculations were done for both intrabony defects and Class II furcation defects. Sample sizes for the equivalence and superiority trials using the same criteria were the same. However, criteria for estimating sample sizes for equivalence clinical trials require much smaller differences between groups, resulting in much larger sample sizes. A criterion of a 20% difference between groups of the total therapeutic effect resulted in sample sizes which ranged from 64 to 127 in equivalence clinical trials. These samples sizes are much larger than have been generally used in clinical trials investigating periodontal regeneration.

Treatment of human mucogingival defects utilizing a bioabsorbable membrane with and without a demineralized freeze-dried bone allograft.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

The relative efficacy of 0.1% and 0.2% delmopinol mouthrinses in inhibiting the development of supragingival dental plaque and gingivitis in man.

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 (P < 0.0003, ANOVA) and the concentration of DMP (P < 0.0001, ANOVA). In contrast, the gingivitis index was not related to the concentration of DMP (P > 0.05, ANOVA). No adverse effects were noted or reported during this clinical trial.

Periodontal therapy in young adults with severe generalized periodontitis.

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.

Maintenance therapy in young adults with severe generalized periodontitis.

The purpose of this study was to evaluate one year of maintenance therapy in young adults with severe periodontitis (SP) who had previously received periodontal therapy consisting of root planing and scaling followed by open flap debridement. Subjects were evaluated with clinical and microbiological measurements at 3, 6, 9, and 12 months following the completion of active therapy. Subjects were included in the study if they completed a minimum of two evaluation appointments. Monitoring of these subjects during the maintenance phase was analyzed by three methods. First, changes in mean attachment level and mean probing depth were calculated at 3-month intervals to determine if the subjects continued to lose or gain attachment and/or had periodontal pockets of increasing or decreasing depth. Second, the frequency of periodontal breakdown was determined and compared to breakdown rates of subjects in other patient populations. Third, future changes in attachment level were related to the presence or absence of two putative periodontal pathogens, Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis in subgingival plaque. Mean attachment level remained constant in 13 subjects who completed one year of maintenance therapy. However, mean probing depth increased at a yearly rate of 0.19 mm and in periodontally-involved sites pocket depth increased at a yearly rate of 0.65 mm both of which were statistically significantly different from 0 (P < .05). The frequency of periodontal breakdown in this study was higher than reported in other similar studies of different periodontitis patient populations. The remainder of the data in the study was from 21 subjects who had completed at least two recall appointments.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship of serum antibody to attachment level patterns in young adults with juvenile periodontitis or generalized severe periodontitis.

The goal of this study was to relate attachment loss patterns in early onset periodontitis subjects (juvenile periodontitis n = 47 and severe (generalized) periodontitis n = 52) with antibody reactivities to 25 bacterial strains which were suspected periodontal pathogens. The 25 antibody reactivities were screened by correlation analysis. Eleven strains were found to be significantly related to attachment loss. Using these 11 reactivities, stepwise multiple linear regression with plaque and age as covariates was used to further relate the reactivities within each subject group. Plaque was significantly related to the number of teeth with slight, moderate, or severe attachment loss. A significant inverse relationship was found between antibody reactivity with Haemophilus actinomycetemcomitans Y4 and the number of teeth having slight or moderate attachment loss. Similarly a significant inverse relationship between antibody reactivity with Bacteroides gingivalis and the number of teeth having moderate or severe attachment loss was found. The inverse relationship between the two antibody reactivities and attachment loss patterns were independent of the positive relationship of plaque. These relationships suggest that the failure to mount a substantial antibody response to these organisms leads to greater and more widespread periodontal disease in early onset periodontitis subjects.

Effects of guided bone regeneration around commercially pure titanium and hydroxyapatite-coated dental implants. I. Radiographic analysis.

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 assessed radiographic density 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 (control). Standardized radiographs were taken at 1 week and 4 months post-implant placement. Computer-assisted densitometric image analysis (CADIA) was performed at 6 areas of interest (coronal, middle, and apical defect areas mesial and distal to each implant) for each of the implant sites. Significantly greater increase in bone density was obtained using DFDBA/ePTFE compared to ePTFE alone or the controls; likewise, ePTFE alone resulted in greater bone density change than the controls. There were no significant differences in radiographic bone density adjacent to Ti versus HA-coated implants. When 3 dogs having postoperative membrane complications were eliminated from the analysis, the results were similar with the exception that defects adjacent to Ti implants had significantly less density gain when compared to HA-coated implants. The results of this study indicate the use of DFDBA/ePTFE in large surgically-created defects promotes a denser healing of bone adjacent to implants when measured radiographically than either ePTFE alone or no treatment.

A comparison of IgG antibody reactive with Bacteroides forsythus and Porphyromonas gingivalis in adult and early-onset periodontitis.

Recent work has indicated that Bacteroides forsythus and Porphyromonas gingivalis are significant local risk factors for periodontitis. Several reports find that both organisms are frequently associated with periodontitis lesions and often are present together. We have previously shown that early-onset periodontitis patients seropositive for P. gingivalis have less attachment loss than seronegative patients. In this study, we determined serum IgG antibody concentrations reactive with B. forsythus in adult and early-onset periodontitis patients using an ELISA and used P. gingivalis in the same populations as a positive control. The results for P. gingivalis were consistent with previous work and indicated that 47%, 36%, and 33% of adult, generalized early-onset, and localized juvenile patients were seropositive, respectively. Mean serum IgG concentrations for the three groups were 5.36 microg/ml, 5.65 microg/ml, and 5.44 microg/ml for adult, generalized early-onset, and localized juvenile patients, respectively. In contrast, for B. forsythus only 11%, 14%, and 10% of adult, generalized early-onset, and localized juvenile patients were seropositive, with mean serum IgG concentrations of 0.46 microg/ml, 0.46 microg/ml, and 0.47 microg/ml, respectively. This suggests that B. forsythus is either poorly immunogenic or less invasive than P. gingivalis. If most patients fail to mount an immune response to B. forsythus and it is invasive, it may explain why this organism is a risk factor for disease.

Effects of guided bone regeneration around commercially pure titanium and hydroxyapatite-coated dental implants. II. Histologic analysis.

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 (P < 0.0001: DFDBA/ePTFE > ePTFE alone > control). HA-coated implants had significantly greater osseointegration within the defect than Ti implants (P < 0.0001). Average trabeculation of newly formed bone in the defect after healing was significantly greater for HA-coated implants than for titanium (P < 0.0001), 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.

The influence of smoking and race on adult periodontitis and serum IgG2 levels.

Smoking is a known risk factor for developing periodontal diseases, but the risk appears to be greater for white smokers than black smokers. Furthermore, it has been reported that young white subjects have significantly lower levels of serum IgG2 than their non-smoking counterparts while young black adult subjects are generally not affected by smoking. These relationships prompted the hypothesis that adult white subjects, including periodontitis subjects, who smoked would have more attachment loss than adult black subjects and that smoking would be associated with lower serum IgG2 levels in adult white subjects but not in adult black subjects. Smoking status was established from serum cotinine levels determined by radioimmunoassay. Serum IgG subclass levels were determined using radial immunodiffusion. White adult periodontitis (AP) and non-periodontitis (NP) subjects who smoked had greater mean attachment loss per site than their non-smoking counterparts. Furthermore, smoking white AP subjects and their age-matched NP controls had substantially less IgG2 in their serum. In marked contrast, we were unable to detect any increase in periodontal destruction or a significant decrease in serum IgG2 levels in smoking black AP subjects or their age-matched controls. However, IgG1 and IgG4 levels were reduced in smoking black AP subjects. IgG3 was the only subclass in adults that was unaffected by smoking. IgG2 can be a good opsonin and may help control periodontitis-associated bacteria in adults. Even though a cause-and-effect relationship has not been established, the association between a smoking-related decrease in serum IgG2 and an increase in periodontal destruction in white subjects is striking.

Actinobacillus actinomycetemcomitans in families afflicted with periodontitis.

The purpose of this study was to determine the prevalence of Actinobacillus actinomycetemcomitans (Aa) in individuals from families where at least one individual has an early onset form of periodontitis. Twenty-three families with 73 subjects were evaluated in this study. Forty-seven early onset periodontitis subjects outside the 23 families were also studied. Prevalence of detection of Aa in family members ranged from 49% to 66% among groups constituted by clinical findings indicative of no loss of attachment, adult periodontitis, generalized severe juvenile periodontitis, or localized juvenile periodontitis. Whether the data were analyzed by subject or by site, no statistical differences could be found in prevalence (proportion of positive samples) among those clinical groups. The only significant difference was that localized juvenile periodontitis subjects had higher concentrations of Aa in their Aa-positive sites than did the other clinical groups. The prevalence of Aa-positive sites in subjects without attachment loss, but who are members of families in which early onset periodontitis is represented, was much higher than in other reports where periodontally healthy subjects were not related to early onset periodontitis cases. This suggests that Aa may be transmitted among members of families in which one or more members has an early onset form of periodontitis.

Is loss of attachment due to root planning and scaling in sites with minimal probing depths a statistical or real occurrence?

BACKGROUND: Following root planing and scaling many studies have implied an association between a loss of clinical attachment at sites with initially shallow pockets (1 to 3 mm) and gains in attachment level for deeper probing depths. However, these effects are also consistent with a statistical phenomenon referred to as regression towards the mean. This principle suggests that extreme values will moderate the next time they are recorded. The purpose of this report was to estimate the effect that regression towards the mean has on perceived changes in attachment level after root planing and scaling. METHODS: During the initial examination, 2 different investigators conducted 2 full-mouth probings. Two quadrants were randomly selected to be root planed and scaled until the root surfaces were smooth by tactile touch of an explorer. The 2 remaining quadrants were not treated. At 4 to 6 weeks after treatment, another full mouth probing was done. An examiner who was blind to the quadrants that had been scaled measured attachment level and probing depth after therapy. This study design provided periodontal measurements before and after root planing and scaling, measurements before and after a period of 4 to 6 weeks of no therapy, and duplicate measurements at the beginning of the study. RESULTS: Using the repeat examination when no true change could occur, shallow sites (< or =3 mm of probing depth) showed average negative differences between repeat attachment level measurements (-0.23 mm), which mimicked loss of periodontal attachment. Deep sites, (>6 mm) showed average positive values (0.40) mimicking gain in attachment level. These results suggest that regression towards the mean is a significant effect in this data set. Both shallow non-scaled and scaled sites had similar differences in repeat measures (-0.28 mm, -0.25 mm) which were also similar to and not statistically different from changes after therapy for both non-scaled (-0.21 mm) and scaled sites (-0.08 mm). Thus not only does this data set exhibit regression towards the mean, but it explains the majority of perceived loss of periodontal attachment after scaling at sites that have minimal probing depth. CONCLUSIONS: These results suggest that the majority of perceived loss of attachment due to scaling at sites of minimal probing depth that have been reported in many studies may be due a statistical phenomenon called regression towards the mean.