Relationship of gingival bleeding, gingival suppuration, and supragingival plaque to attachment loss

A Comparative Analysis of Treatment-Related Changes in the Diagnostic Biomarker Active Metalloproteinase-8 Levels in Patients with Periodontitis

BACKGROUND

Previous studies have revealed the potential diagnostic utility of aMMP-8, an active form of MMP-8, in periodontal and peri-implant diseases. While non-invasive point-of-care (PoC) chairside aMMP-8 tests have shown promise in this regard, there is a dearth of literature on the evaluation of treatment response using these tests. The present study aimed to investigate treatment-related changes in aMMP-8 levels in individuals with Stage III/IV-Grade C periodontitis compared to a healthy control group, using a quantitative chairside PoC aMMP-8 test, and to determine its correlation with clinical parameters.

METHODS

The study included 27 adult patients (13 smoker, 14 non-smoker) with stage III/IV-grade C periodontitis and 25 healthy adult subjects. Clinical periodontal measurements, real-time PoC aMMP-8, IFMA aMMP-8, and Western immunoblot analyses were performed before and 1 month after anti-infective scaling and root planing periodontal treatment. Time 0 measurements were taken from the healthy control group to test the consistency of the diagnostic test.

RESULTS

Both PoC aMMP-8 and IFMA aMMP-8 tests showed a statistically significant decrease in aMMP-8 levels and improvement in periodontal clinical parameters following treatment (p < 0.05). The PoC aMMP-8 test had high diagnostic sensitivity (85.2%) and specificity (100.0%) for periodontitis and was not affected by smoking (p > 0.05). Treatment also reduced MMP-8 immunoreactivity and activation as demonstrated by Western immunoblot analysis.

CONCLUSION

The PoC aMMP-8 test shows promise as a useful tool for the real-time diagnosis and monitoring of periodontal therapy.

Long term comparison of the prognostic performance of PerioRisk, periodontal risk assessment, periodontal risk calculator, and staging and grading systems

BACKGROUND

Clinicians predominantly use personal judgment for risk assessment. Periodontal risk assessment tools (PRATs) provide an effective and logical system to stratify patients based on their individual treatment needs. This retrospective longitudinal study aimed to validate the association of different risk categories of four PRATs (Staging and grading; Periodontal Risk Assessment (PRA); Periodontal Risk Calculator; and PerioRisk) with periodontal related tooth loss (TLP), and to compare their prognostic performance.

METHODS

Data on medical history, smoking status, and clinical periodontal parameters were retrieved from patients who received surgical and non-surgical periodontal treatment. A comparison of the rate of TLP and non-periodontal related tooth loss (TLO) within the risk tool classes were performed by means of Kruskal-Wallis test followed by post-hoc comparison with the Bonferroni test. Both univariate and multivariate Cox Proportional hazard regression models were built to analyze the prognostic significance for each single risk assessment tool class on TLP.

RESULTS

A total of 167 patients with 4321 teeth followed up for a mean period of 26 years were assigned to four PRATs. PerioRisk class 5 had a hazard ratio of 18.43, Stage 4 had a hazard ratio of 7.99, and PRA class 3 had a hazard ratio of 6.13 compared with class/stage I. With respect to prognostic performance, PerioRisk tool demonstrated the best discrimination and model fit followed by PRA.

CONCLUSION

All PRATs displayed very good predictive capability of TLP. PerioRisk showed the best discrimination and model fit, followed by PRA.

Is bleeding on probing a reliable clinical indicator of peri-implant diseases?

Bleeding on probing (BOP) is regarded as an indispensable diagnostic tool for evaluating periodontal disease activity; however, its role in peri-implant disease is more intricate. Much of the confusion about the interpretation originates from drawing parallels between periodontal and peri-implant conditions. BOP can originate from two forms of probing in implants: traumatic or pathologic induction. This, in addition to the dichotomous scale of BOP can complicate diagnosis. The objective of this commentary is to discuss the following: 1) the value of BOP as a diagnostic tool for peri-implant diseases; 2) the reasons it should be distinct from value for diagnosing periodontal and peri-implant diseases; and 3) the current best evidence on how to implement it in daily clinical practice. A comprehensive bleeding index is proposed for evaluating and monitoring peri-implant conditions. BOP should be used in addition to other parameters such as visual signs of inflammation, probing depth, and progressive bone loss before a peri-implant diagnosis is established.

Fixed Orthodontic Retainers Do Not Seem to Adversely Affect Periodontal Health

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION

The effects of fixed orthodontic retainers on periodontal health: A systematic review. Arn M, Dristas K, Pandis N, Kloukos D. Am J Orthod Dentofacial Orthop 2020;157:156-64.

SOURCE OF FUNDING

Information is not available and the authors did state any specific funding for this study and report no potential conflicts of interest.

TYPE OF STUDY/DESIGN

Systematic review.

Parameters to Define Peri-Implantitis: A Review and a Proposed Multi-Domain Scale

Peri-implant diseases have received much attention since dental implants are generally used in contemporary dentistry. Several contributing factors associated with the development of peri-implant diseases have also been investigated. The prevalence of peri-implantitis has been reported but with great heterogeneity because of a lack of a universally accepted classification system that could define the extent and severity of peri-implantitis. Several parameters-including radiographic bone loss, probing depth, bleeding on probing, and suppuration-have been introduced in these reports to assist with clinical diagnosis. This article provides an objective evaluation of these parameters based on currently available evidence, offers further recommendations, and proposes a multidomain scale for diagnosis of peri-implantitis. Future investigations and modifications may be needed to develop a comprehensive, evidence-based classification system that addresses the multifactorial etiology of peri-implant diseases.

A randomized clinical trial of oral hygiene care programmes during stroke rehabilitation

OBJECTIVES

The objectives of this study were to evaluate and compare the effectiveness of an advanced oral hygiene care programme (AOHCP) and a conventional oral hygiene care programme (COHCP) in improving oral hygiene, and reducing gingival bleeding among patients with stroke during outpatient rehabilitation.

METHODS

Subjects were randomized to receive (i) the COHCP comprising a manual toothbrush, toothpaste, and oral hygiene instruction, or (ii) the AOHCP comprising a powered toothbrush, 0.2% chlorhexidine mouthrinse, toothpaste, and oral hygiene instruction. Dental plaque, gingival bleeding, and other clinical oral health outcomes were assessed at baseline, the end of the clinical trial, and the end of observation period. Development of infectious complications was also monitored.

RESULTS

Participants of both programmes had a significant reduction in the percentages of sites with moderate to abundant dental plaque (p<0.001) and with gingival bleeding (p<0.05). Those in the AOHCP had significantly less plaque and gingival bleeding than those in the COHCP controlling for other factors at the end of the clinical trial period (both p<0.001) and the observational period (plaque: p<0.05, gingival bleeding: p<0.01).

CONCLUSIONS

Although both oral hygiene care programmes were effective in terms of plaque and gingival bleeding control, the AOHCP was more effective than the COHCP in reducing dental plaque and gingival bleeding.

CLINICAL SIGNIFICANCE

This study highlighted the value of oral hygiene programmes within stroke outpatient rehabilitation and provides evidence to advocate for the inclusion of oral hygiene care programmes within stroke outpatient rehabilitation for patients with normal cognitive abilities.

A comprehensive periodontal treatment project: The periodontal status, compliance rates, and risk factors

Background/purpose

The comprehensive periodontal treatment project (CPTP) is being implemented in Taiwan since 2010. This retrospective study compared the periodontal status, compliance rates, and influence of risk factors for periodontal recurrence and tooth loss among groups of patients who accepted CPTP and conventional periodontal treatment (CPT).

Materials and methods

A total of 161 patients who received periodontal therapy were investigated and divided into compliant (n = 94) and noncompliant (n = 67) groups. Patients in the compliant group were further assigned to two subgroups: CPT with a postcard recall (PR) system (CPT + PR, n = 48) and CPTP with a PR system (CPTP + PR, n = 46). Demographic characteristics and periodontal parameters, including the probing pocket depth (PPD), bleeding on probing (BOP), and plaque control record (PCR), were collected for comparison between the subgroups. The risk factors for periodontal recurrence and tooth loss were statistically analyzed.

Results

The 161 patients were followed-up for a mean of 3.8 years. The patients in the CPTP + PR subgroup exhibited shallower PPD, less BOP, improved PCR, and fewer tooth loss. Age, smoking, PPD ≥7 mm, and PCR ≥30% were associated with periodontal recurrence, whereas age, diabetes, BOP ≥30%, and duration of the follow-up period were correlated with tooth loss. PR apparently increased the compliance rate of patients (27.3% vs. 77.7%).

Conclusion

CPTP with PR led to an optimal and stable periodontal status in patients. Compliant patients maintained a significantly improved periodontal status as compared with noncompliant patients.

Detection ofTannerella forsythiaand/orPrevotella intermediaMight Be Useful for Microbial Predictive Markers for the Outcome of Initial Periodontal Treatment in Koreans

A proportion of diseased sites in periodontal disease do not respond to the initial treatment, which might be due in part to the presence of specific microbial pathogens. The aim of this study was to clarify the value of microbial screening for predicting the outcome of periodontal treatment in Koreans using a polymerase chain reaction (PCR). This study enrolled 32 adults with periodontal disease. Microbial and clinical examinations were performed at the baseline and after the initial treatment (professional toothbrushing, scaling, and root planing). Subgingival plaque samples were taken from four sites in each subject (total 128 samples). PCR was used to detect the four putative pathogenic bacteria. There was an improvement in the average of each clinical measurement after the initial treatment. However, approximately half of the sites exhibiting bleeding upon probing (BOP) at the baseline still exhibited bleeding after treatment. There was a close association between the presence of BOP and the presence of Tannerella forsythia (formerly Bacteroides forsythus) and/or Prevotella intermedia. Furthermore, the sites harboring both T. forsythia and P. intermedia at the baseline had a poorer response to treatment than the sites where these two species were not detected. Therefore, microbial screening for T. forsythia and P. intermedia might be useful for predicting the treatment outcome in Koreans.

Efficacy of Subgingival Application of Xanthan-based Chlorhexidine Gel Adjunctive to Full-mouth Root Planing Assessed by Real-time PCR: A Microbiologic and Clinical Study

BACKGROUND AND AIMS

The aim of this clinical investigation was to compare clinical and microbiological effectiveness of adjunctive CHX gel in the treatment of periodontitis.

MATERIALS AND METHODS

Twenty-four subjects with localized or generalized moderate-to-severe chronic periodontitis underwent scaling and root planing. One tooth in each quadrant with a probing depth of >4 mm was chosen for combined gel and SRP, with contralateral tooth as control (SRP treated site). Clinical assessment was carried out at baseline and 1 and 3 months later; microbial assessment was performed by real-time PCR. Periodontal probing depth (PPD) was considered as primary outcome.

RESULTS

Twenty patients completed the study. Baseline PPDs were 4.90±0.78 and 5.05±0.79 in the SRP and gel groups, respectively (P>0.05), which decreased to 3.67±0.59 and 3.7±0.83 one month after treatment and 3.25±0.65 and 3.38±0.79 three months after treatment. Although values decreased significantly in both groups after one and three months (P=0.001 in the SRP and P=0.001 in the gel group), the inter-group difference was not significant neither at one-month (P=0.47) nor at three-month (P=0.77) intervals. The only clinical parameters exhibiting statistically significant inter-group differences was BOP in both one-month (P=0.004) and three-month (P=0.0001) intervals. All the other clinical measurements showed significant decreases after one and three months in both sites but without inter-group differences.

CONCLUSION

Subgingival application of xanthan chlorhexidine gel combined with scaling and root planing reduced bleed-ing of periodontal pockets. Clinical trials to evaluate effectiveness of this gel in aggressive and severe periodontitis modified by systemic factors are suggested.

Pellicle and early dental plaque in periodontitis patients before and after surgical pocket elimination

OBJECTIVE

Gingival inflammation may affect the composition of the dental pellicle and initial acquisition of bacteria, which in turn could affect the healing of the periodontal pocket. The aim of this study was to examine the dental pellicle and early supragingival biofilms in periodontitis patients with an established subgingival infiltrate before and after surgical pocket elimination.

MATERIALS AND METHODS

Eleven patients with remaining pockets were selected. Samples were taken before and after surgical pocket elimination and after subsequent experimental gingivitis. Pellicle proteins were analyzed by SDS-PAGE, immunoblotting and image analysis and 4-h supragingival plaque by culturing.

RESULTS

The inflammatory status affected to a greater extent the concentration of plasma proteins than salivary proteins in the dental pellicle. The highest plasma protein concentrations were observed at remaining periodontal pockets where also the highest bacterial counts were found. The TVC was reduced on the gingival tooth surfaces (p < 0.05) after pocket elimination and increased slightly during experimental gingivitis. The finding of streptococci was highest on the incisal tooth surfaces and increased after surgery. Gram-negative anaerobes were sparse but seen more often before than after pocket elimination and on gingival than on incisal surfaces.

CONCLUSIONS

This study suggests that increased amounts of plasma proteins in the pellicle formed in the presence of remaining periodontal pockets may foster the acquisition of bacteria, including proteolytic Gram-negative species. This, in turn, results in an increased de novo plaque formation rate.

Disease progression: identification of high-risk groups and individuals for periodontitis

AIMS

While the role of bacteria in the initiation of periodontitis is primary, a range of host-related factors influence the onset, clinical presentation and rate of progression of disease. The objectives of this review are (1) to present evidence for individual predictive factors associated with a patient's susceptibility to progression of periodontitis and (2) to describe the use of prognostic models aimed at identifying high-risk groups and individuals in a clinical setting.

METHODS

Relevant publications in the English language were identified after Medline and PubMed database searches. Because of a paucity of longitudinal studies investigating factors including clinical, demographic, environmental, behavioural, psychosocial, genetic, systemic and microbiologic parameters to identify individuals at risk for disease progression, some association studies were also included in this review.

FINDINGS AND CONCLUSIONS

Cigarette smoking is a strong predictor of progressive periodontitis, the effect of which is dose related. High levels of specific bacteria have been predictive of progressive periodontitis in some studies but not all. Diabetics with poor glycaemic control have an increased risk for progression of periodontitis. The evidence for the effect of a number of putative factors including interleukin-1 genotype, osteoporosis and psychosocial factors is inconclusive and requires further investigation in prospective longitudinal studies. Specific and sensitive diagnostic tests for the identification of individuals susceptible to disease progression are not yet a reality. While factors assessed independently may not be valuable in predicting risk of future attachment loss, the combination of factors in a multifactorial model may be useful in identifying individuals at risk for disease progression. A number of multifactorial models for risk assessment, at a subject level have been developed but require validation in prospective longitudinal studies.

A systematic review of professional mechanical plaque removal for prevention of periodontal diseases

AIM

To investigate the effect of professional mechanical plaque removal (PMPR) on the prevention of periodontal diseases.

METHODS

We searched for randomized controlled trials, controlled clinical trials and cohort studies from 1950 to October 2004. Screening and data abstraction were conducted independently and in duplicate. Critical appraisal of studies was based on objective criteria and evidence tables were constructed.

RESULTS

From 2179 titles and abstracts, 132 full-text articles were screened and 32 studies were relevant. Evidence exists that PMPR in adults, particularly in combination with oral hygiene instruction (OHI), may be more effective than no treatment judged by surrogate measures. The evidence for a benefit of PMPR+OHI over OHI alone is less clear. The optimum frequency of PMPR has not been investigated although more frequent PMPR is associated with improved markers of health. The strength of evidence for these results ranges from weak to moderate due to risk of bias, inconsistent results, lack of appropriate statistics and small sample size.

CONCLUSIONS

There appears to be little value in providing PMPR without OHI. In fact, repeated OHI might have a similar effect as PMPR. Some forms of PMPR might achieve greater patient satisfaction. There is little difference in beneficial or adverse effects of different methods of PMPR.

Cross-sectional evaluation of clinical parameters to select high prevalence populations for periodontal disease: the site comparative severity methodology

Epidemiological studies have shown strong evidence that periodontal disease does not affect all subjects in the same manner. There are subjects and sites with higher risk for disease progression. This study tested parameters to select "a priori" sites and subjects potentially at risk. The data from periodontal clinical examinations of 2273 subjects was used. The clinical loss of attachment was measured in 6 sites per tooth. Using computer software, the patients were distributed into 14 age groups, with intervals of 5 years, from 11 years to greater than 75 years of age. The measure of each site was compared with the average and the median values of the subject age group, with the results indicating site comparative severity (SCS). Three global parameters were calculated: parameter 1 (P1) - percentage of sites with clinical attachment loss > 4 mm; parameter 2 (P2) - percentage of sites with clinical attachment loss > 7 mm; parameter 3 (P3) - percentage of sites with clinical attachment loss surpassing the median value for the age group by 100% or more. There were 1466 (65%) females and 807 (35%) males. Most subjects had P1, P2 and P3 values less than 30%. Parameter 3 allowed a division of the sample similar to that of Parameters 1 and 2, with the advantage of analyzing the subject in relation to his/her age group. It was suggested that the methodology of SCS is useful for selecting a population with a high disease prevalence, and that cut-off lines between 10% and 20% would be appropriate for using Parameter 3.

A systematic review on the use of residual probing depth, bleeding on probing and furcation status following initial periodontal therapy to predict further attachment and tooth loss

BACKGROUND

Chronic periodontitis affects many adults. Initial cause related therapy (ICRT) is aimed at elimination of factors causing disease progression.

OBJECTIVES

To use a systematic review process of peer reviewed publications to assess the predictive value of residual probing depths (PD), bleeding on probing (BOP) and furcation involvement (FI) in determining further loss of attachment and tooth loss following ICRT.

MATERIAL AND METHODS

An electronic search of the Cochrane Oral Health Group specialized register, MEDLINE and EMBASE, was performed using specific search terms to identify studies assessing the predictive value of residual probing depths (PD), bleeding on probing (BOP) and furcation involvement (FI) in determining further loss of attachment and tooth loss following ICRT.

RESULTS

The searches resulted in 941 uniquely identified studies. Titles and abstracts were then independently screened by two reviewers (S.R. and G.R.P.) to identify publications that met specific inclusion criteria. The agreement between the reviewers was assessed and statistical analysis failed to demonstrate a difference between the two reviewers (kappa-value: 0.94, P = 0.003). Detailed review of 47 included publications resulted in acceptance of one publication which utilized data based on patient as unit of observation. This study included 16 subjects over 42 months demonstrating that residual probing depths are predictive of further disease progression whereas persisting bleeding on probing are not.

CONCLUSIONS

Data based on one study suggest that residual probing depths are predictive of further disease progression. The implications for carefully designed multicentre randomized clinical control trials are many.

Supportive periodontal care: the effect of periodic subgingival debridement compared with supragingival prophylaxis with respect to clinical outcomes

BACKGROUND

The programme of supportive periodontal care (SPC) is essential to the long-term stability of patients with chronic periodontitis. The clinical strategy for SPC is often determined according to 'clinical needs' of the patient and is thus determined by clinical observation and individual decision-making rather than being based on the best available clinical evidence.

OBJECTIVE

To evaluate the effectiveness of supragingival prophylaxis vs. sub-gingival debridement for SPC following the treatment of chronic periodontitis.

SEARCH STRATEGY

Computerized for Medline and the Cochrane Oral Health Group Specialty Trials Register. Hand searching of the Journals of Clinical Periodontology, Periodontal Research and Periodontology. Reference lists from relevant articles were scanned and the authors of eligible studies were contacted to obtain additional information.

SELECTION CRITERIA

Studies were selected if they were designed as a prospective clinical trial in which patients with chronic periodontitis had followed a programme of SPC, which included at least one of the regimens of interest in part of the mouth, for a minimum of 12 months.

DATA COLLECTION AND ANALYSIS

Information regarding methods, patients, interventions (SPC), outcome measures and results were extracted independently, in duplicate, by two reviewers (P.A.H., G.McC.). Absent data were recorded as such and incomplete data were sought from the researchers wherever possible.

RESULTS

In all, 28 papers were identified by the manual and electronic searches; 11 papers were eligible for inclusion. Only one study reported a direct comparison of the two SPCs of interest. The data were reported as mean changes in probing depth and attachment level between baseline and the 12-month follow-up point. For coronal scaling DeltaPD = 0.59 mm [0.13], DeltaAL = -0.13 mm [0.19]. For subgingival debridement DeltaPD = 0.37 mm [0.15], DeltaAL = -0.14 mm [0.18]. There were no significant differences between the SPC regimens. The weighted mean DeltaPD [95% confidence intervals] for the five additional studies that reported supragingival prophylaxis as the SPC regimen was 1.15 mm [-0.17, 2.38]. The weighted mean DeltaPD [95% confidence intervals] for the four studies that reported subgingival debridement as the SPC regimen was 0.56 mm [0.37, 1.47]. The difference between the SPC treatments for the mean DeltaPD is therefore 0.23 mm. The confidence interval for the combined studies was very wide [0.37, 1.47] and very little additional information is gained unless some strong assumptions are made about the comparability of the populations from which the samples are drawn. Such an assumption was not considered appropriate. The weighted mean DeltaAL [95% confidence intervals] for the six additional studies that reported supragingival prophylaxis as the SPC regimen was 0.18 mm [-0.38, 0.74]. The weighted mean DeltaAL [95% confidence intervals] for the six additional studies that reported supragingival prophylaxis as the SPC regimen was 0.50 mm [0.11, 0.89]. The difference between the SPC treatments for mean DeltaAL is 0.32 mm. The confidence interval [-0.36, 1.00] is very wide and the data from the additional studies provide little extra information than that reported in the one study that compared the treatments directly.

CONCLUSION

It is not possible to make any firm recommendations regarding clinical practice based on the crude meta-analysis and the review of these 11 studies. The best available evidence indicates that SPC regimens of supragingival prophylaxis and subgingival debridement are comparable with respect to the clinical outcomes of probing depth and attachment levels at 12 months post non-surgical treatment.

Periodontal risk assessment, diagnosis and treatment planning

The prevention and treatment of the periodontal diseases is based on accurate diagnosis, reduction or elimination of causative agents, risk management and correction of the harmful effects of disease. Prominent and confirmed risk factors or risk predictors for periodontitis in adults include smoking, diabetes, race, P. gingivalis, P. intermedia, low education, infrequent dental attendance and genetic influences. Several other specific periodontal bacteria, herpesviruses, increased age, male, sex, depression, race, traumatic occlusion and female osteoporosis in the presence of heavy dental calculus have been shown to be associated with loss of periodontal support and can be considered to be risk indicators of periodontitis. The presence of furcation involvement, tooth mobility, and a parafunctional habit without the use of a biteguard are associated with a poorer periodontal prognosis following periodontal therapy. An accurate diagnosis can only be made by a thorough evaluation of data that have been systematically collected by: 1) patient interview, 2) medical consultation as indicated, 3) clinical periodontal examination, 4) radiographic examination, and 5) laboratory tests as needed. Clinical signs of periodontal disease such as pocket depth, loss of clinical attachment and bone loss are cumulative measures of past disease. They do not provide the dentist with a current assessment of disease activity. In an attempt to improve the ability to predict future disease progression, several types of diagnostic tests have been studied, including host inflammatory products and mediators, enzymes, tissue breakdown products and subgingival temperature. In general, the usefulness of these tests for predicting future disease activity remains to be established in terms of sensitivity, specificity and predictive value. Although microbiological analysis of subgingival plaque is not necessary to diagnose and treat most patients with periodontitis, it is helpful when treating patients with unusual forms of periodontal disease such as early-onset, refractory and rapidly progressive disease. There appears to be a strong genetic component in some types of periodontal disease and genetic testing for disease susceptibility has potential for future use, but more research is needed to determine its utility for use in clinical practice. Treatment of the periodontal diseases may be divided into four phases: systemic, hygienic, corrective and maintenance or supportive periodontal therapy. Regardless of the type of treatment provided, periodontal therapy will fail or will be less effective in the absence of adequate supportive periodontal therapy.

Association of early onset periodontitis microbiota with aspartate aminotransferase activity in gingival crevicular fluid

OBJECTIVES

The objective of this study was to determine the relationship between the activity of the enzyme aspartate aminotransferase (AST) in gingival crevicular fluid (GCF) using the colorimetric PerioGard (PTM) test and the subgingival microflora in early onset periodontitis lesions.

MATERIAL AND METHODS

The study population consisted of 25 otherwise healthy individuals exhibiting early onset periodontitis (EOP). In each patient four experimental sites were identified comprising one deep periodontal pocket (PD >5 mm) randomly chosen in each quadrant. Bacterial samples were obtained from the experimental sites, consecutively cultured anaerobically and in 10% CO(2) using selective and nonselective media. Isolates were characterized to species level by conventional biochemical tests and various identification kits. Clinical measurements as well as AST activity, assessed either as positive or negative using the PTM, were recorded at the same sites.

RESULTS

Sixty-two sites exhibited AST positive and 38 AST negative activity. Analysis of bacterial counts using the ANOVA (Mann Whitney U-test) showed that Streptococcus intermedius, Peptostreptococcus micros, Campylobacter concisus, Bacteroides forsythus, Camplobacter gracilis, Campylobacter rectus and Selenomonas sputigena were significantly higher in sites with AST-positive activity. The odds ratio of having high prevalence of S. intermedius, P. micros, C. concisus, B. forsythus, C. gracilis, C. rectus and S. sputigena in the presence of a positive AST site was very high (range: 3.5-17.0). Streptococcus sanguis, Actinomyces naeslundii, Gemella morbillorum, Capnocytophaga gingivalis, Veillonella parvula, Fusobacterium varium, Eubacterium lentum and Prevotella oralis were detected in significantly higher proportions in sites with AST negative activity and manifested a negative odds ratio in the presence of AST positive sites. The logistic regression analysis revealed that smoking and bleeding upon probing showed a significant association with AST activity, while plaque and suppuration were not found to be significant predictors of AST activity. The co-infection of Porphyromonas gingivalis, B. forsythus and P. micros, or P. gingivalis, B. forsythus and C. rectus were found to be significantly associated with the AST activity (p<0.001). AST positive sites revealed significantly higher occurrence of co-infections by P. gingivalis, B. forsythus, S. sputigena or by P. gingivalis, B. forsythus, S. intermedius than AST negative sites (p<0.001). P. gingivalis, B. forsythus, A. naeslundii co-infection was found significantly higher in the AST negative sites (p<0.001).

CONCLUSIONS

The present study found a high level of agreement between the presence of putative periodontal pathogens and positive AST scores at periodontal sites that clinically were considered to be potentially disease active. Prospective studies should be performed to confirm the findings.

Herpes viruses and periodontopathic bacteria in early-onset periodontitis

OBJECTIVES

This study examined the occurrence of human herpes viruses and suspected periodontopathic bacteria in early-onset periodontitis patients who experienced progressive disease in at least 2 periodontal sites during the maintenance phase of therapy.

MATERIAL AND METHODS

In each of 16 individuals (9 male and 7 female; mean age 33.1+/-2.6 years), subgingival plaque samples were collected from 2 deteriorating and 2 stable periodontitis sites. A nested polymerase chain reaction method determined the presence of human cytomegalovirus (HCMV), Epstein-Barr virus type 1 (EBV-1) and herpes simplex virus (HSV). A 16s rRNA polymerase chain reaction method identified Porphyromonas gingivalis, Dialister pneumosintes, Bacteroides forsythus and Actinobacillus actinomycetemcomitans.

RESULTS

HCMV was detected in 59.4% of active and in 12.5% of stable sites (p<0.001), EBV-1 in 43.8% of active and in 12.5 % of stable sites (p=0.01), HSV in 34.5% of active and in 9.4% of stable sites (p=0.03), and co-infection with any of the 3 test herpesviruses in 43.8% of active and in 3.1% of stable sites (p<0.001). P. gingivalis was detected in 71.9% of active and in 37.5% of stable sites (p=0.01), D. pneumosintes in 62.5% of active and in 18.8% of stable sites (p=0.04), co-infection with P. gingivalis and D. pneumosintes in 50% of active and in 0% of stable sites (p<0.001), and co-infection with any 3 or 4 of the test bacteria in 40.6% of active and in 0% of stable sites (p=0.001). All periodontitis sites showing herpesvirus co-infection and all but one site showing P. gingivalis and D. pneumosintes co-infection revealed bleeding upon probing.

CONCLUSIONS

HCMV, EBV-1, HSV and herpesvirus co-infection, as well as P. gingivalis, D. pneumosintes and P. gingivalis-D. pneumosintes co-infection were statistically associated with active periodontitis. Herpesviruses are immunosuppressive and may set the stage for overgrowth of subgingival P. gingivalis, D. pneumosintes and other periodontopathic bacteria. Understanding the significance of herpesviruses in human periodontitis may allow for improved diagnosis, more specific therapy and, ultimately, disease prevention.

Use of a fluorogenic septapeptide matrix metalloproteinase assay to assess responses to periodontal treatment

BACKGROUND

Quantification of gingival crevicular fluid matrix metalloproteinase activity may provide improved assessment of periodontal disease status and response to treatment. A fluorogenic matrix metalloproteinase substrate assay (FSA) has been developed using a methoxycoumarin-containing septapeptide analog of the alpha2(I) collagen cleavage site. This substrate exhibits increased fluorescence following cleavage by many matrix metalloproteinases, and the enzyme activity can be readily estimated with a fluorimeter. Here we compared this assay with classical methods of periodontal assessment including bleeding on probing, crevicular fluid flow, and probing depth to assess its utility as an indicator of changes in periodontal status and treatment response.

METHODS

Complete measurements of probing depth were obtained for Ramfjord teeth on subjects who had been previously treated for periodontitis. Subjects were subsequently divided into groups based on existing periodontal disease severity: gingivitis (n = 21), stable periodontitis (n = 41), and severe periodontitis (n = 50). Crevicular fluid volume, bleeding on probing, and FSA were measured at each Ramfjord tooth or substitute. After baseline measurements, subjects received subgingival scaling and prophylaxis; 3 months later, they were reassessed.

RESULTS

FSA measurements were positively associated with severity of disease at baseline. After treatment there were substantial reductions of FSA in gingivitis (approximately 51%; P <0.01) and severe periodontitis (approximately 45%; P <0.001), but not in stable periodontitis (13%; P >0.2). All groups showed a positive association between FSA measurements and higher bleeding scores at individual sites. FSA measurements were also positively associated with crevicular fluid flow at baseline, but after treatment there was a approximately 67% decrease (P <0.01) in the highest crevicular fluid flow class. There were significant reductions of FSA at follow-up for sites with probing depths between 0 to 3 mm (23%; P <0.05) and 4 to 6 mm (31%; P <0.05). However, the largest reduction was for sites with probing depth between 7 to 9 mm (49%; P <0.001).

CONCLUSIONS

These results indicate that monitoring patients by measurement of matrix metalloproteinase levels in gingival crevicular fluid with the quenched fluorescent substrate assay provides estimates of inflammatory status, periodontal destruction, and response to treatment, especially in more severe periodontitis lesions.

Comparison of four methods of assessing root surface debridement

BACKGROUND

While there is great interest in measuring the efficacy of root surface debridement, there is little consensus on how this might be best achieved. The aim of this study was therefore to compare four different methods of assessing root surface debridement in their ability to discriminate between ultrasonically instrumented root surfaces and non-instrumented control surfaces.

METHODS

Single-session subgingival root debridement was performed by an experienced operator on 30 teeth prior to their extraction. Following extraction, efficacy of root surface debridement was measured by percentage of remaining calculus, instrument efficiency, modified instrument efficiency, and percentage apical plaque border. In addition, the effect of probing depth landmark (apical plaque border versus connective tissue attachment) on outcomes was assessed.

RESULTS

The results indicated that percentage apical plaque border demonstrated highly statistically significant differences between instrumented and control surfaces (P= 0.02). No other assessment method was able to discriminate between instrumented and non-instrumented surfaces, and this may be a function of the low amount of root surface calculus in the experimental sample. In addition, choice of probing depth landmark had a notable effect on the outcomes for instrument efficiency and modified instrument efficiency. Ninety-five percent limits of agreement of interexaminer reproducibility were found to be much higher than intra-examiner measurement for all four methods of assessment.

CONCLUSIONS

Percentage apical plaque border appeared to be potentially more useful than other methods for assessing the efficacy of debridement of periodontally involved root surfaces, particularly for measuring instrument penetrability.

Changes in the prevalence of residual pockets and tooth loss in treated periodontal patients during a supportive maintenance care program

Bleeding on probing and the presence of deep periodontal pockets are considered to be the best site-specific indicators for periodontal disease progression during the maintenance phase of periodontal therapy. A major emphasis of supportive periodontal care (SPC) programs, therefore, has been the control of bleeding pockets. This investigation retrospectively evaluated the changes in the prevalence of bleeding on probing, periodontal pockets, bleeding periodontal pockets and the prevalence of tooth loss in a random sample of 273 periodontal patients participating in a supportive maintenance care program at a University Clinic. During an observation period of 67+/-46 months (range 5 months to 23 years), the overall incidence of all causes of tooth mortality was 0.23+/-0.49 teeth per patient per year of observation. 56% of subjects, however, did not experience any tooth loss, while less than 10% of patients lost more than 3 teeth. Thus, participation in the SPC program was effective in preventing tooth loss in the majority of patients. During the SPC period, however, a significant increase in the prevalence of periodontal pockets, and of bleeding on probing positive periodontal pockets, in particular, was observed. At completion of active periodontal therapy, 56.4% of patients were free from bleeding pockets. This decreased to a mere 13.6% at the latest SPC evaluation. The observed increases in the number of bleeding pockets was significantly associated with: longer times since completion of active periodontal therapy, more advanced periodontal diagnosis, higher %s of bleeding sites in the dentition, cigarette smoking, lack of inclusion of periodontal surgery in the active treatment phase, tooth loss, and the response to the active phase of periodontal treatment. The data presented in the paper indicate that the observed increase in the prevalence of bleeding pockets and tooth loss was not homogeneously distributed in the studied SPC population. Rather, high risk groups of individuals could be identified. It is suggested that better knowledge of risk indicators may lead to improved and more efficient risk management efforts during periodontal maintenance care.

Contemporary interpretation of probing depth assessments: diagnostic and therapeutic implications. A literature review

This paper addresses the diagnostic and therapeutic implications of increased probing depths. In general, in untreated and treated patients, when deep and shallow probing depths are compared, the data indicate that deep sites are associated with increased bleeding upon probing, elevated subgingival temperatures, higher levels of pathogens, more probing errors, a greater amount of infiltrated connective tissue, reduced ability to remove subgingival deposits with root planing, and diminished effectiveness of oral hygiene to alter the subgingival microbiota. Clinical trials demonstrate that probing depth is not a good predictor of future disease progression. However, deep sites are at greater risk of disease progression than shallow sites in untreated and treated patients. Furthermore, the deeper the probing depth, the greater the risk of future disease progression. Overall, the preponderance of evidence indicates that it is advantageous, but not always necessary, for patients to have shallow probing depths. With regards to surgical reduction of probing depths beyond that attained with non-surgical therapy, clinicians need to consider the advantages (e.g., ease of maintenance, reduced risk of disease progression) and disadvantages (e.g., root sensitivity, cosmetic defects) of treatment procedures. Since numerous variables require consideration (e.g., response to root planing, goals of therapy, acceptable level of risk for future disease progression), treatment decisions will vary depending on the patient and the desired clinical outcome at specific sites.

Risk assessment for periodontal diseases

Assessment of risk for periodontitis is still in its infancy. Nevertheless, a sufficient amount of dependable information exists to begin using risk assessment in the day to day practice of dentistry. The purpose of this paper is to summarise existing information about risks for periodontitis in a manner that is useful to practitioners. Risks for moderate to severe periodontitis that have been identified include cigarette smoking, advancing age, diabetes mellitus and certain other systemic conditions. These include, osteoporosis and HIV infection and conditions such as irradiation and immunosuppressive drugs that interfere with normal host defences, specific pathogenic bacteria in the subgingival flora, microbial deposits and poor oral hygiene status, bleeding on probing, previous disease experience and severity, and inheritance. Some risks such as pathogenic bacteria in the subgingival flora are strongly linked to causation of the disease while others such as bleeding on probing may indicate enhanced risk for future disease but are not known to be involved in causation and still others such as advancing age may be background factors that enhance susceptibility. While some risks such as cigarette smoking can be modified to lower the level of risk, others such as ageing are immutable and cannot be modified but need to be considered in overall risk assessment. A goal of periodontal diagnosis, treatment planning and therapy is to lower risk for future periodontal deterioration to the maximal extent. One approach to achieving this goal is described.

Efficacy of a sonic toothbrush on inflammation and probing depth in adult periodontitis

This single-blind, 8-week study compared the efficacy of a sonic toothbrush and a manual brush in 40 patients with adult periodontitis. Qualitative clinical indices and quantitative laboratory methods were used to monitor the periodontal status of 3 pockets 5 to 7 mm deep in each subject. Patients were randomly assigned either a sonic or manual toothbrush. The two groups were comparable with respect to age, gender, and anatomical location of the test sites. Data were collected from all sites at baseline and at 2, 4, and 8 weeks. Over the 8-week period, both groups showed significant improvements in the clinical indices used. Descriptive statistics indicated the sonic brush group had greater improvement than the manual group in the clinical parameters (gingival index, bleeding index, probing depth, and clinical attachment level). Gingival crevicular fluid (GCF) flow was significantly lower in the sonic brush group (P = 0.018). Considerable variation was present in the levels detected for both inflammatory cytokines tested, however, concentration of interleukin-1 beta was significantly lower in the GCF of sonic group patients (P = 0.05), while concentration of interleukin-6 was significantly reduced in both groups (P < or = 0.05) (t tests). Under these conditions, there is some evidence to suggest that the sonic toothbrush is more beneficial in resolving inflammation in patients with moderate periodontal disease.

The relationship between gingival crevicular fluid cathepsin B activity and periodontal attachment loss in chronic periodontitis patients: a 2-year longitudinal study

This study aims to determine whether gingival crevicular fluid (GCF) cathepsin B levels, total activity (TA) and concentration (EC) predict progressive attachment loss (AL). Seventy-five previously untreated patients with moderate periodontitis were recruited. GCF was collected from 16 molar and premolar mesiobuccal sites and probing attachment level (PAL) and probing depth (PPD) were measured with an electronic probe. Gingival, gingival bleeding and plaque indices were then scored. Prior to baseline patients were given basic periodontal treatment after which the above procedures were repeated. Carefully localized radiographs were taken of the test teeth and repeated annually. Patients were seen 3-monthly for 2 yr and the procedures were repeated. One hundred and twenty-one AL sites, 90 rapid AL (RAL) and 31 gradual AL (GAL), in 49 patients were detected. Cathepsin B levels (TA & EC) at RAL sites were significantly higher (p < 0.0001) than paired control sites at the attachment loss time (ALT) and prediction time (PT). Mean levels (TA & EC) over the study period at GAL sites were significantly higher (p < 0.0001) than paired control sites. Using a critical value (CV) of 7.5 microU/30 s (TA) and 30 microU/microL (EC) showed a sensitivity of 100% and specificity of 99.83% (TA) and 100% and 99.75%(EC) at both ALT & PT. Mean cathepsin B levels (TA & EC) were significantly higher (p < 0.0001) at RAL and GAL sites than non-attachment loss (NAL) sites in AL patients in intrapatient comparisons and mean patient levels were significantly higher (p < 0.0001) in AL patients than NAL patients in interpatient comparisons. These results indicate that GCF cathepsin B may serve as a predictor of attachment loss.

A 2-year longitudinal study of elastase in human gingival crevicular fluid and periodontal attachment loss

The purpose of this study is to determine whether gingival crevicular fluid (GCF) elastase total activity (TA) and concentration (EC) correlate with and predict progressive attachment loss (AL). 75 previously untreated patients with moderate periodontitis were recruited. GCF was collected from 16 molar and premolar mesiobuccal sites and probing attachment loss (PAL), probing depth (PPD), gingival index (GI), gingival bleeding index (GBI) and plaque index (Pl.I) were measured. PAL and PPD were measured with an electronic, constant pressure probe. Patients were given basic periodontal treatment prior to baseline when the above procedures were repeated. In addition, carefully localised radiographs were taken of the test teeth and repeated annually. Patients were seen at 3 months intervals to 2 years and the procedures were repeated. 119 AL sites were detected and 89 of these were rapid AL sites (RAL) and 30 were gradual AL sites (GAL). Elastase levels (TA & EC) at RAL sites were significantly higher (p < or = 0.0001) than paired control sites in the same patient at both the attachment loss time (ALT) and the prediction time (PT). The mean levels (TA & EC) over the study period at GAL sites were significantly higher (p < or = 0.0001) than paired control sites in the same patient. Using a critical value (CV) of 125 micronsU/30 s (TA) and 400 micronsU/micronsL (EC) in 2 x 2 contingency tables showed a sensitivity of 100% and specificity of 99.95% (TA) and a sensitivity of 100% and specificity of 99.91% (EC) at the PT with very similar values at the ALT. Patient level comparisons showed that the mean elastase levels (TA & EC) were significantly higher (p < or = 0.0001) at RAL and GAL sites than non-attachment loss (NAL) sites in AL patients and that the mean levels were significantly higher (p < or = 0.0001) in AL patients than NAL patients. All these results indicate that these CVs for GCF elastase activity may serve as a predictors of future attachment loss.

Indices to measure gingival bleeding

Gingival bleeding is an objective, easily assessed sign of inflammation that is associated with several periodontal diseases. Many bleeding indices have been devised; some assess bleeding as simply present or absent, whereas others use grading in an attempt to assess severity of bleeding. The choice of which index to use depends on whether the purpose is an epidemiological survey, a clinical study, diagnosis and treatment, or patient motivation. Bleeding may be elicited manually with toothpicks, dental floss or a periodontal probe, but a controlled-force probe, although more expensive, causes less trauma and less false-positive bleeding from healthy tissues. As a predictor of periodontal disease progression, bleeding on probing has low sensitivity owing to a high frequency of false-positive responses, but has high specificity in that failure to bleed indicates health. There is evidence that smokers have less, or delayed, gingival bleeding when compared with non-smokers; therefore smoking needs to be controlled for in studies of gingival bleeding. Measurement of gingival bleeding tendency should be an integral part of a comprehensive oral examination. In clinical practice, the use of a graded bleeding index is more likely to identify sites that are at risk of further destructive activity. For monitoring individual patients, both for response to initial therapy and during maintenance, a modified Sulcus Bleeding Index (mSBI) with three bleeding scores is recommended in preference to dichotomous scoring of bleeding.

Suitability of gingival indices for use in therapeutic trials. Is bleeding a sine qua non?

A number of gingival indices have been described which include visual and invasive components, either separately or in combination. In selecting indices for use in gingivitis therapeutic trials, some investigators maintain that only invasive indices should be used, since indices that include a bleeding-on-provocation component are deemed to be the most objective. Other investigators, however, maintain that non-invasive indices are the more appropriate insofar as invasive procedures will not only disrupt the plaque at the gingival margin, but could also mildly traumatize the tissue and present an impediment to assessing examiner standardization and reproducibility. This paper discusses these aspects of gingivitis evaluation. The data indicate that all validated indices, whether invasive or non-invasive, have some degree of both objectivity and subjectivity. Therefore, the selection of an appropriate index will depend upon the ability of a given index to achieve the objectives of the clinical trial in which it is to be utilized.

Microbiological monitoring

If periodontal disease is due to a limited number of bacterial species, then continuous maximal plaque suppression is not the only possibility for prevention and therapy. Specific elimination or reduction of pathogenic bacteria from plaque becomes a valid alternative. Recent studies indicate that the elimination of certain putative pathogens is particularly difficult. New diagnostic methods should allow the choice of better suited procedures, make chosen procedures more effective (through better timing, dosage, selection of devices or drugs, increase of specificity, etc.) or lead to the elimination of unnecessary work (e.g., the treatment of non-susceptible sites or patients). The benefit of newly proposed tests depends on the possible impact of the obtained information on clinical decisions and on the consequences these decisions have for treatment. Thus, diagnostic methods and therapeutical options have to be evaluated together.

Effects of treatment on gingival crevicular collagenase, stromelysin and tissue inhibitor of metalloproteinases and their ability to predict response to treatment

Fibroblast collagenase (FIB-CL) and stromelysin (SL) are members of a family of enzymes which are capable of degrading most of the extracellular matrix macromolecules. Extracellular control of these enzymes is performed by tissue inhibitor of metalloproteinases (TIMP). During healing, inflammation and normal tissue turnover, levels of MMPs and TIMP will change. The effect of treatment on the levels of FIB-CL, SL and TIMP as well as their ability, at baseline, to predict the outcome of therapy was investigated. 21 patients each provided 8 gingival crevicular fluid (GCF) samples from sites with probing depths > or = 4 mm. Clinical recordings and GCF sampling were performed at 3 time points. Assays for SL, FIB-CL and TIMP were performed by a sandwich ELISA. Attachment level changes were detected by the "tolerance method". The ability of the GCF constituents to predict the response to treatment was assessed by comparing pre-treatment levels between sites which did or did not show attachment gain after therapy. Although no GCF constituents could reliably predict the response to treatment, SL reduced significantly (p = 0.029) after the hygiene phase of therapy. In addition, both SL and TIMP levels showed a highly significant reduction at follow-up visit (p = 0.003 and p = 0.005 respectively). Thus, SL and TIMP levels are reduced by treatment, but these GCF proteins do not appear to have an ability to predict treatment outcome from baseline.

Prognostic criteria for the efficiency of non-surgical periodontal therapy in advanced periodontitis

The aim of the study was to find out which clinical, radiographic and microbiological variables can be used as prognostic criteria for the efficiency of the commonly used initial treatment protocol comprising scaling, root planning and instruction on oral hygiene in advanced adult periodontitis. 46 patients (mean age 48 years) with untreated, advanced periodontitis volunteered for the study. The clinical examination included recordings of plaque, gingival and calculus indices, probing pocket depths, bleeding and suppuration after probing, probing attachment levels and furcation involvements. Infrabony and furcation lesions were assessed from panoramic radiographs. Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis were cultured from the deepest, most inflamed periodontal Pockets, from surface of the tongue and from saliva. 3 months after the completion of non-surgical treatment comprising meticulous scaling and root planing and instruction on oral hygiene, the healing was assessed clinically, and 13 patients were assigned to a maintenance care programme (MC) and 33 to further treatment procedures (FT). Evaluation of the baseline clinical and radiographic data showed a significantly higher %s of > or = 6 mm deep periodontal pockets, surfaces with suppuration, and sites with subgingival calculus, as well as higher numbers of infrabony lesions, in FT-patients than in MC-patients. Subgingival A. actinomycetemcomitans was isolated at baseline in 55% of the FT-patients and in 38% of the MC-patients, and P. gingivalis in 27% and 23%, respectively. A. actinomycetemcomitans was eradicated by non-surgical treatment from only one patient. P. gingivalis was detected in 15% of the patients in both groups after treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

The influence of supragingival plaque control on clinical and microbial outcomes following the use of antibiotics for the treatment of periodontitis

Although supragingival plaque control is essential to successful periodontal therapy, the role of plaque control following systemic antibiotic use in periodontal disease has not been well defined. This study evaluated, following antibiotic use, which clinical and microbial parameters appeared to be influenced primarily by the antibiotics, independent of plaque control, and which outcomes appeared to be dependent on plaque control. Two hundred thirty-six patients (236) with moderate to severe periodontitis were clinically evaluated and microbial samples were taken by their private-practice periodontists. All patients were treated with scaling and root planing and a variety of systemic antibiotics, which were selected based on the microbial and clinical profile of the patient. Three months after therapy, patients were reevaluated and grouped by post-treatment plaque control, as either having very good oral hygiene (LoPl: N = 143; < or = 10% plaque-covered surfaces) or poor oral hygiene (HiPl: N = 93; > or = 25% plaque-covered surfaces). The two groups had different plaque and bleeding scores initially, but similar numbers of pockets probing > 5 mm and similar microbial patterns. Although the LoPl group had a significantly greater reduction in plaque than the HiPl group, bleeding scores and probing depths changed comparably in both groups after antibiotic therapy. Plaque control influenced outcomes significantly, but in a complex manner. The LoPl group exhibited a significantly greater reduction in certain bacteria, for example P. gingivalis. Interactions between plaque control and specific microbial parameters significantly affected clinical outcomes, although neither alone was sufficient to predict outcomes following antibiotic therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Beta-hemolytic streptococci in advanced periodontitis

The distribution of serotypes of beta-hemolytic streptococci was examined in 718 periodontitis patients. Subgingival samples were obtained with paper points from the 3 deepest lesions in each patient, transported in VMGA III, plated onto brucella agar with 5% sheep blood and incubated anaerobically for 7 days. Serotyping and speciation were performed with Meritec-Strep Beta-Hemolytic Streptococcus Grouping Set and the Analytab 20S Streptococcus System. Beta-hemolytic streptococci were recovered from 33.7% of patients and averaged 10.5% of the total viable counts in culture-positive subjects. The organisms occurred with higher prevalence in patients 35 years or older than in younger patients. The predominant serotypes were F (62.9%), non-typeable (18.1%), B (6.9%), C (6.9%) and G (5.2%). 100% of beta-hemolytic streptococci were sensitive to penicillin, but less than 5% were sensitive to tetracycline, metronidazole or ciprofloxacin. Beta-hemolytic streptococci may contribute to inflammatory periodontal disease and may interfere with healing after therapy.

The periodontally-involved root surface

Recent years have seen much research on the periodontally-involved root surface. Many of these studies have produced results which suggest that plaque contaminants of the root surface are only superficially placed, and capable of being removed by gentle means. Further research has attested to the difficulties in rendering periodontally-involved root surfaces free of calculus deposits by instrumentation, yet clinical studies show that periodontal disease can be managed by root planing. It is concluded that root surface debridement is best assessed on the basis of the healing response and that it should aim to disrupt plaque on and remove plaque from the periodontally-involved root surface rather than to remove part of the root surface itself.

Principles and pitfalls of clinical trials design

Periodontitis and gingivitis trials can involve many complex experimental designs. The selection of a specific design and the details of the protocol can influence the magnitude of any effect observed, the generalizability of the results, and the clinical significance of the findings. The purpose of this paper is to review selected aspects of clinical trials including the overall clinical experimental design, controls, outcomes, sample size, and patient selection. Particular emphasis will be placed on periodontitis trials.

General issues in efficacy, equivalency, and superiority trials: clinical considerations

The design of clinical trials aimed at treating different types of periodontal diseases must take into account the prevalence of the disease in the population and the relationship of various descriptors, which may vary from disease to disease. For screening purposes, patients should be selected with disease in the high-severity range, in order to maximize the likelihood of detecting a therapeutic effect. Subsequent trials may be designed around a more representative group of subjects. Therapies must be evaluated on the basis of actual clinical changes, rather than their effect on presumed etiologic factors. The observed changes must be of clinical as well as statistical significance. The distribution of periodontal diseases within a dentition may affect as few as one or as many as over one hundred sites. Strategies are needed to correlate events observed at sites within the dentition, i.e. tooth surface-based measurements or scores, with events that are subject-based, e.g. concentration of blood or salivary components.

Report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

Subjects of the past decade in the dental literature are reflected in this year's Committee report. We note the decrease in the prevalence of caries, the influence of dental implants, the advancements in dental materials, and the continued efforts to control adhesive events in the oral cavity. This year we included comments from and about many significant review articles published this past year. The Committee continues to be concerned about the quality of some of the work reported and the quality of the reporting. We have attempted to select the distinguished work, that which provides new information to our profession. The subjects covered include pulp biology, caries prevention, periodontics, implants, craniomandibular function and dysfunction, occlusion, and dental materials.