Randomized controlled trial of toothbrushing to reduce ventilator-associated pneumonia pathogens and dental plaque in a critical care unit

AIM

To investigate the effect of a powered toothbrush on colonization of dental plaque by ventilator-associated pneumonia (VAP)-associated organisms and dental plaque removal.

MATERIALS AND METHODS

Parallel-arm, single-centre, examiner- and analyst-masked randomized controlled trial. Forty-six adults were recruited within 48 h of admission. Test intervention: powered toothbrush, control intervention: sponge toothette, both used four times per day for 2 min. Groups received 20 ml, 0.2% chlorhexidine mouthwash at each time point.

RESULTS

The results showed a low prevalence of respiratory pathogens throughout with no statistically significant differences between groups. A highly statistically significantly greater reduction in dental plaque was produced by the powered toothbrush compared with the control treatment; mean plaque index at day 5, powered toothbrush 0.75 [95% confidence interval (CI) 0.53, 1.00], sponge toothette 1.35 (95% CI 0.95, 1.74), p=0.006. Total bacterial viable count was also highly statistically significantly lower in the test group at day 5; Log(10) mean total bacterial counts: powered toothbrush 5.12 (95% CI 4.60, 5.63), sponge toothette 6.61 (95% CI 5.93, 7.28), p=0.002.

CONCLUSIONS

Powered toothbrushes are highly effective for plaque removal in intubated patients in a critical unit and should be tested for their potential to reduce VAP incidence and health complications.

Consensus Report: 2nd European Workshop on Tobacco Use Prevention and Cessation for Oral Health Professionals

Tobacco use has been identified as a major risk factor for oral disorders such as cancer and periodontal disease. Tobacco use cessation (TUC) is associated with the potential for reversal of precancer, enhanced outcomes following periodontal treatment, and better periodontal status compared to patients who continue to smoke. Consequently, helping tobacco users to quit has become a part of both the responsibility of oral health professionals and the general practice of dentistry. TUC should consist of behavioural support, and if accompanied by pharmacotherapy, is more likely to be successful. It is widely accepted that appropriate compensation of TUC counselling would give oral health professionals greater incentives to provide these measures. Therefore, TUC-related compensation should be made accessible to all dental professionals and be in appropriate relation to other therapeutic interventions. International and national associations for oral health professionals are urged to act as advocates to promote population, community and individual initiatives in support of tobacco use prevention and cessation (TUPAC) counselling, including integration in undergraduate and graduate dental curricula. In order to facilitate the adoption of TUPAC strategies by oral health professionals, we propose a level of care model which includes 1) basic care: brief interventions for all patients in the dental practice to identify tobacco users, assess readiness to quit, and request permission to re-address at a subsequent visit, 2) intermediate care: interventions consisting of (brief) motivational interviewing sessions to build on readiness to quit, enlist resources to support change, and to include cessation medications, and 3) advanced care: intensive interventions to develop a detailed quit plan including the use of suitable pharmacotherapy. To ensure that the delivery of effective TUC becomes part of standard care, continuing education courses and updates should be implemented and offered to all oral health professionals on a regular basis.

Improving the effectiveness of tobacco use cessation (TUC)

This paper includes an update of a Cochrane systematic review on tobacco use cessation (TUC) in dental settings as well as narrative reviews of possible approaches to TUC and a more detailed discussion of referral for specialist TUC services. On the basis of these reviews we conclude that interventions for tobacco users in the dental setting increase the odds of quitting tobacco. However, the evidence is derived largely from patients using smokeless tobacco. Pharmacotherapy (such as nicotine replacements, bupropion and varenicline) is recommended for TUC in medical settings but has received little assessment in dental applications, although such evidence to date is promising. Whether the dental setting or referral to specialist TUC services is the most effective strategy to help people to quit tobacco use is unclear. An effective specialist service providing best available TUC care alone may not be the answer. Clearly, such services should be both accessible and convenient for tobacco users. Closer integration of specialist services with referrers would also be advantageous in order to guide and support oral health professionals make their referral and to maximise follow-up of referred tobacco users. Future research direction may consider investigating the most effective components of TUC in the dental settings and community-based trials should be a priority. Pharmacotherapy, particularly nicotine replacement therapy, should be more widely examined in dental settings. We also recommend that various models of referral to external and competent in-house TUC specialist services should be examined with both experimental and qualitative approaches. In addition to overall success of TUC, important research questions include facilitators and barriers to TUC in dental settings, preferences for specialist referral, and experiences of tobacco users attempting to quit, with dental professionals or specialist services, respectively.

The effect of bias on the magnitude of clinical outcomes in periodontology: a pilot study

AIM

To investigate potential effect of bias on magnitude of outcomes.

MATERIAL AND METHODS

Randomized-controlled trials (RCTs) from the Cochrane Database of Systematic Reviews were searched. Methodological quality of RCTs was assessed in terms of allocation concealment and examiner masking. Meta-regression analyses were used to determine associations between the quality assessments and magnitude of treatment outcomes on probing depth and attachment level.

RESULTS

Thirty-five RCTs were identified from five systematic reviews. Adequate allocation concealment and examiner masking were found in 24% and 64% of trials respectively. There were no statistically significant differences in the magnitude of treatment outcomes comparing adequate versus inadequate or unclear allocation concealment, nor comparing adequate and inadequately examiner masked trials. However, a retrospective power calculation indicated 265 RCTs would be needed to demonstrate a statistically significant effect for the impact of bias on CAL as an outcome measure for a 0.5 mm exaggeration of mean difference between test and control.

CONCLUSIONS

There is insufficient evidence to support or refute the theory that the bias from improper methods of allocation concealment and examiner masking affect the magnitude of clinical outcomes in periodontology trials. The pilot data provide a baseline for sample size calculations in future research.

Guided tissue regeneration for periodontal infra-bony defects

BACKGROUND

Conventional treatment of destructive periodontal (gum) disease arrests the disease but does not usually regain the bone support or connective tissue lost in the disease process. Guided tissue regeneration (GTR) is a surgical procedure that specifically aims to regenerate the periodontal tissues when the disease is advanced and could overcome some of the limitations of conventional therapy.

OBJECTIVES

To assess the efficacy of GTR in the treatment of periodontal infra-bony defects measured against conventional surgery (open flap debridement (OFD)) and factors affecting outcomes.

SEARCH STRATEGY

We conducted an electronic search of the Cochrane Oral Health Group Trials Register, MEDLINE and EMBASE up to April 2004. Handsearching included Journal of Periodontology, Journal of Clinical Periodontology, Journal of Periodontal Research and bibliographies of all relevant papers and review articles up to April 2004. In addition, we contacted experts/groups/companies involved in surgical research to find other trials or unpublished material or to clarify ambiguous or missing data and posted requests for data on two periodontal electronic discussion groups.

SELECTION CRITERIA

Randomised, controlled trials (RCTs) of at least 12 months duration comparing guided tissue regeneration (with or without graft materials) with open flap debridement for the treatment of periodontal infra-bony defects. Furcation involvements and studies specifically treating aggressive periodontitis were excluded.

DATA COLLECTION AND ANALYSIS

Screening of possible studies and data extraction was conducted independently. The methodological quality of studies was assessed in duplicate using individual components and agreement determined by Kappa scores. Methodological quality was used in sensitivity analyses to test the robustness of the conclusions. The Cochrane Oral Health Group statistical guidelines were followed and the results expressed as mean differences (MD and 95% CI) for continuous outcomes and risk ratios (RR and 95% CI) for dichotomous outcomes calculated using random-effects models. Any heterogeneity was investigated. The primary outcome measure was change in clinical attachment.

MAIN RESULTS

The search produced 626 titles, of these 596 were clearly not relevant to the review. The full text of 32 studies of possible relevance was obtained and 15 studies were excluded. Therefore 17 RCTs were included in this review, 16 studies testing GTR alone and two testing GTR+bone substitutes (one study had both test treatment arms).No tooth loss was reported in any study although these data are incomplete where patient follow up was not complete. For attachment level change, the mean difference between GTR and OFD was 1.22 mm (95% CI Random Effects: 0.80 to 1.64, chi squared for heterogeneity 69.1 (df = 15), P < 0.001, I(2) = 78%) and for GTR + bone substitutes was 1.25 mm (95% CI 0.89 to 1.61, chi squared for heterogeneity 0.01 (df = 1), P = 0.91). GTR showed a significant benefit when comparing the numbers of sites failing to gain 2 mm attachment with risk ratio 0.54 (95% CI Random Effects: 0.31 to 0.96, chi squared for heterogeneity 8.9 (df = 5), P = 0.11). The number needed to treat (NNT) for GTR to achieve one extra site gaining 2 mm or more attachment over open flap debridement was therefore 8 (95% CI 5 to 33), based on an incidence of 28% of sites in the control group failing to gain 2 mm or more of attachment. For baseline incidences in the range of the control groups of 3% and 55% the NNTs are 71 and 4. Probing depth reduction was greater for GTR than OFD: 1.21 mm (95% CI 0.53 to 1.88, chi squared for heterogeneity 62.9 (df = 10), P < 0.001, I(2) = 84%) or GTR + bone substitutes, weighted mean difference 1.24 mm (95% CI 0.89 to 1.59, chi squared for heterogeneity 0.03 (df = 1), P = 0.85). For gingival recession, a statistically significant difference between GTR and open flap debridement controls was evident (mean difference 0.26 mm (95% CI Random Effects: 0.08, 0.43, chi squared for heterogeneity 2.7 (df = 8), P = 0.95), with a greater change in recession from baseline for the control group. Regarding hard tissue probing at surgical re-entry, a statistically significant greater gain was found for GTR compared with open flap debridement. This amounted to a weighted mean difference of 1.39 mm (95% CI 1.08 to 1.71, chi squared for heterogeneity 0.85 (df = 2), P = 0.65). For GTR + bone substitutes the difference was greater, with mean difference 3.37 mm (95% CI 3.14 to 3.61). Adverse effects were generally minor although with an increased treatment time for GTR. Exposure of the barrier membrane was frequently reported with a lack of evidence of an effect on healing.

AUTHORS' CONCLUSIONS

GTR has a greater effect on probing measures of periodontal treatment than open flap debridement, including improved attachment gain, reduced pocket depth, less increase in gingival recession and more gain in hard tissue probing at re-entry surgery. However there is marked variability between studies and the clinical relevance of these changes is unknown. As a result, it is difficult to draw general conclusions about the clinical benefit of GTR. Whilst there is evidence that GTR can demonstrate a significant improvement over conventional open flap surgery, the factors affecting outcomes are unclear from the literature and these might include study conduct issues such as bias. Therefore, patients and health professionals need to consider the predictability of the technique compared with other methods of treatment before making final decisions on use. Since trial reports were often incomplete, we recommend that future trials should follow the CONSORT statement both in their conduct and reporting. There is therefore little value in future research repeating simple, small efficacy studies. The priority should be to identify factors associated with improved outcomes as well as investigating outcomes relevant to patients. Types of research might include large observational studies to generate hypotheses for testing in clinical trials, qualitative studies on patient-centred outcomes and trials exploring innovative analytic methods such as multilevel modelling. Open flap surgery should remain the control comparison in these studies.

Introduction to cumulative meta-analysis in dentistry: lessons learned from undertaking a cumulative meta-analysis in periodontology

Improving health and well-being from the consideration of isolated studies is problematic. Systematic reviews have been developed to address this problem and may include a quantitative data synthesis in the form of a meta-analysis, or a cumulative meta-analysis. The value of systematic reviews depends greatly on the availability and quality of the results of primary research. The objective of the current project was to demonstrate the technique of cumulative meta-analysis in dentistry using data from a previously published systematic review. The process highlights an issue that some trials could not be synthesized due to the lack of reporting of measures of variation. This represents a potential source of bias. Investigators are encouraged to consider their trials as part of an information continuum and to report sufficient detail to permit the trials' incorporation into subsequent syntheses.

Periodontal ultrasonography

OBJECTIVES

The aim of this study was to investigate high-frequency ultrasound imaging for periodontal assessment.

MATERIAL AND METHODS

A newly developed ultrasonic scanner with a frequency of 20 MHz was used. Pig jaws were selected as the experimental model. Three teeth per jaw were imaged with the scanner and duplicate measurements were made of the distance from a fixed landmark on the teeth to the alveolar bone crest. These measurements were compared to transgingival and direct measurements of the same teeth following reflection of the soft tissues. One further jaw was used for histological comparison with the ultrasound image.

RESULTS

Using ultrasonography, it was possible to image the main periodontal structures. The ultrasound measurements showed better repeatability than either of the other two methods (repeatability coefficient: 0.44 mm for ultrasound, 0.93 mm for transgingival probing and 0.6 mm for direct measurements). Also, ultrasound was in better agreement with direct, open probing measurements (0.004 +/- 0.58 mm) than transgingival probing with direct measurements (0 +/- 0.7 mm).

CONCLUSIONS

Ultrasonography provides a highly accurate and repeatable technique for periodontal assessment in this model.

A guide to systematic reviews

Systematic reviews have become widely used for evaluating evidence across all fields of biomedicine. The objective of a systematic review is to provide a comprehensive and contemporary appraisal of research using transparent methods whilst aiming to minimize bias. In essence, research methodology is employed in the conduct of the review. Such reviews are therefore fundamentally different from traditional 'narrative' review articles in their purpose and in their potential to aid clinical decision-making. This paper is a guide to the rationale and nature of systematic reviews and will provide a background to understanding their use in clinical practice.

Utilisation of locally delivered doxycycline in non-surgical treatment of chronic periodontitis. A comparative multi-centre trial of 2 treatment approaches

AIM

In the present 6-month multicentre trial, the outcome of 2 different approaches to non-surgical treatment of chronic periodontitis, both involving the use of a locally delivered controlled-release doxycycline, was evaluated.

MATERIAL AND METHODS

105 adult patients with moderately advanced chronic periodontitis from 3 centres participated in the trial. Each patient had to present with at least 8 periodontal sites in 2 jaw quadrants with a probing pocket depth (PPD) of > or =5 mm and bleeding following pocket probing (BoP), out of which at least 2 sites had to be > or =7 mm and a further 2 sites > or =6 mm. Following a baseline examination, including assessments of plaque, PPD, clinical attachment level (CAL) and BoP, careful instruction in oral hygiene was given. The patients were then randomly assigned to one of two treatment groups: scaling/root planing (SRP) with local analgesia or debridement (supra- and subgingival ultrasonic instrumentation without analgesia). The "SRP" group received a single episode of full-mouth supra-/subgingival scaling and root planing under local analgesia. In addition, at a 3-month recall visit, a full-mouth supra-/subgingival debridement using ultrasonic instrumentation was provided. This was followed by subgingival application of an 8.5% w/w doxycycline polymer at sites with a remaining PPD of > or =5 mm. The patients of the "debridement" group were initially subjected to a 45-minute full-mouth debridement with the use of an ultrasonic instrument and without administration of local analgesia, and followed by application of doxycycline in sites with a PPD of > or =5 mm. At month 3, sites with a remaining PPD of > or =5 mm were subjected to scaling and root planing. Clinical re-examinations were performed at 3 and 6 months.

RESULTS

At 3 months, the proportion of sites showing PPD of < or =4 mm was significantly higher in the "debridement" group than in the "SRP" group (58% versus 50%; p<0.05). The CAL gain at 3 months amounted to 0.8 mm in the "debridement" group and 0.5 mm in the "SRP" group (p=0.064). The proportion of sites demonstrating a clinically significant CAL gain (> or =2 mm) was higher in the "debridement" group than in the "SRP" group (38% versus 30%; p<0.05). At the 6-month examination, no statistically significant differences in PPD or CAL were found between the two treatment groups. BoP was significantly lower for the "debridement" group than for the "SRP" group (p<0.001) both at 3- and 6 months. The mean total treatment time (baseline and 3-month) for the "SRP" patients was 3:11 h, compared to 2:00 h for the patients in the "debridement" group (p<0.001).

CONCLUSION

The results indicate that simplified subgingival instrumentation combined with local application of doxycycline in deep periodontal sites can be considered as a justified approach for non-surgical treatment of chronic periodontitis.

Guided tissue regeneration for periodontal infra-bony defects

BACKGROUND

Conventional treatment of destructive periodontal (gum) disease arrests the disease but does not regain the bone support or connective tissue lost in the disease process. Guided tissue regeneration (GTR) is a surgical procedure that aims to regenerate the periodontal tissues when the disease is advanced and could overcome some of the limitations of conventional therapy.

OBJECTIVES

To assess the efficacy of GTR in the treatment of periodontal infra-bony defects measured against the current standard of surgical periodontal treatment, open flap debridement.

SEARCH STRATEGY

We conducted an electronic search of the Cochrane Oral Health Group specialised trials register and MEDLINE up to October 2000. Hand searching included Journal of Periodontology, Journal of Clinical Periodontology, Journal of Periodontal Research and bibliographies of all relevant papers and review articles up to October 2000. In addition, we contacted experts/groups/companies involved in surgical research to find other trials or unpublished material or to clarify ambiguous or missing data and posted requests for data on two periodontal electronic discussion groups.

SELECTION CRITERIA

Randomised, controlled trials of at least 12 months duration comparing guided tissue regeneration (with or without graft materials) with open flap debridement for the treatment of periodontal infra-bony defects. Furcation involvements and studies specifically treating early onset diseases were excluded.

DATA COLLECTION AND ANALYSIS

Screening of possible studies was conducted independently by two reviewers (RT & IN) and data abstraction by three reviewers (RT, IN & EGL). The methodological quality of studies was assessed in duplicate (RT & IN) using both individual components and a quality scale (Jadad 1998) and agreement determined by Kappa scores. Methodological quality was used in sensitivity analyses to test the robustness of the conclusions. The Cochrane Oral Health Group statistical guidelines were followed (HW) and the results expressed as weighted mean differences (WMD and 95% CI) for continuous outcomes and relative risk (RR and 95% CI) for dichotomous outcomes calculated using random effects models where significant heterogeneity was detected (P < 0.1). The final analysis was conducted using STATA 6 in order to combine both parallel group studies and intra-individual (split-mouth) studies. The primary outcome measure was gain in clinical attachment. Any heterogeneity was investigated.

MAIN RESULTS

We initially included 23 trial reports. Twelve were subsequently excluded. Of these, seven presented six-months data only, three were not fully randomised controlled trials, one used a non-comparable radiographic technique. Eleven studies were finally included in the review, ten testing GTR alone and two testing GTR+bone substitutes (one study had both test treatment arms). For attachment level change, the weighted mean difference between GTR alone and open flap debridement was 1.11 mm (95% CI: 0.63 to 1.59), chi-square for heterogeneity 31.4 (df = 9), p<0.001) and for GTR+bone substitutes was 1.25 mm (95% CI: 0.89 to 1.61, chi-square for heterogeneity 0.01 (df = 1), p=0.91). GTR showed a significant benefit when comparing the numbers of sites failing to gain 2 mm attachment, with relative risk 0.58 (95% CI: 0.38, 0.88, chi-square for heterogeneity 5.72 (df = 3), p=0.13). The number needed to treat (NNT) for GTR to achieve one extra site gaining 2 mm or more attachment over open flap debridement was 8 (95% CI: 4, 33), based on an incidence of 32% of sites in the control group failing to gain 2 mm or more of attachment. For baseline incidences in the range of the control groups of 10% and 55% the NNTs are 24 and 3. Probing depth reduction demonstrated a small but statistically significant benefit for GTR, weighted mean difference 0.80 mm (95% CI: 0.14,1.46, chi-square for heterogeneity 10.0 (df = 4), p=0.04) or GTR+bone substitutes, weighted mean difference 1.24 mm (95% CI: 0.89, 1.59, chi-square for heterogeneity 0.03 (df = 1), p=0.85). No significant difference was noted for gingival recession between GTR and open flap debridement. Regarding hard tissue probing at surgical re-entry, a statistically significant greater gain was found for GTR compared with open flap debridement. This amounted to a weighted mean difference of 1.39 mm (95% CI: 1.08, 1.71, chi-square for heterogeneity 0.85 (df = 2), p=0.65). For GTR+bone substitutes the difference was greater, with mean difference 3.37 mm (95% CI: 3.14, 3.61). Heterogeneity between studies was highly statistically significant for all principal comparisons and could not be explained satisfactorily by sensitivity analyses. The quality of study reporting was poor with seven out of 11 studies graded as poor using the Jadad score. (ABSTRACT TRUNCATED)

A rapid spectrophotometric assay for tetracycline in gingival crevicular fluid

AIM

The aim of this study was to investigate a rapid spectrophotometric assay for its potential to measure tetracycline levels in gingival crevicular fluid (GCF).

MATERIALS AND METHODS

The technique involves complexation of tetracycline with molybdenum in order to shift the absorbance spectrum away from that region where interference with plasma proteins is a problem. The sensitivity of the assay and reproducibility of elution were examined together with an assessment of the effect of plasma proteins. The assay was also tested in a small pilot clinical project, measuring tetracycline levels in GCF following placement of a test gel formulation in 25 periodontal pockets in 5 patients.

RESULTS

The in vitro results showed good sensitivity of the assay over the concentration range tested (0.5-200 microg tetracycline) and with little effect of plasma proteins. Elution from the paper strips was reproducible with a good linear correlation between direct and filter absorbed assays (r=0.9989, p<0.01). The pilot clinical study indicated a mean half-time of tetracycline in GCF of 28 min with confidence intervals of 21 to 34 min, although wide variation between the drug levels of individual periodontal pockets was seen.

CONCLUSIONS

The results indicate good sensitivity for this assay to measure tetracycline hydrochloride in vivo. The potential for rapidly processing large numbers of samples contrasts with the assay time and limited sample throughput of other methods such as high pressure liquid chromatography (HPLC) and suggests that the technique may be a useful addition to current techniques for measuring tetracycline hydrochloride in vivo.

Diamond-coated sonic tips are more efficient for open debridement of molar furcations. A comparative manikin study

BACKGROUND/AIMS

The aim of this study was to compare the efficacy of open debridement of class II and III furcations by a new diamond-coated sonic instrument tip (Sonicparo) with a conventional sonic insert (Sonicrecall) and hand instruments (Gracey curettes).

METHOD

Open debridement was simulated using a manikin head and standardised plastic teeth. The efficacy of debridement was examined by 3 parameters: residual root surface marker, 'tooth' weight loss and time taken for debridement. The teeth used were 1st and 2nd upper and lower molars. Upper left and lower right molars were chosen to represent class II furcation involvements and upper right and lower left molars class III furcation involvements. Each tooth was debrided 4 times with each instrument for both class of furcations.

RESULTS

The results of this study showed significantly less residual marker area comparing Sonicparo with Gracey curettes (mean difference 2.52 mm2, p<0.001). However, no significant differences in marker removal were observed between Sonicrecall inserts and the other instruments. Sonicparo inserts also took significantly less time to debride the furcation than Gracey curettes (mean difference 98.3 s, p<0.001) or Sonicrecall instruments (mean difference 74.3 s, p<0.001). However no significant differences were found between instruments concerning weight loss of the plastic teeth.

CONCLUSIONS

It was concluded from this in-vitro study that the Sonicparo insert was a more efficient instrument for open molar furcation debridement than Sonicrecall and hand instruments (Gracey curettes) when considering both marker removal and debridement time.

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.

Periodontal flap surgery with 25% metronidazole gel. (1). Clinical outcomes

OBJECTIVES

The aim of this 12-month, randomised controlled, single-blind, parallel-arm study, was to test whether local application of a slow-release antimicrobial might exert an adjunctive effect on healing following periodontal surgery.

MATERIALS AND METHODS

Following non-surgical therapy, 43 patients with moderate to advanced periodontitis, had at least 1 pocket > or =6 mm with bleeding on probing (BOP). Treatment consisted of modified Widman surgery with no osseous resection. The test group (T) received gel application over the exposed root surface and the control group (C) received no gel, followed by flap closure.

RESULTS

38 patients completed the study: 5 patients did not attend at 12 months and could not be traced. Surgery was very successful in both groups in improving probing depths (mean baseline: T=7.4 mm, C=7.1 mm; 12 months T=3.7 mm, C=3.5 mm) and relative attachment levels (baseline: T=10.3 mm, C=10.1 mm; 12 months T=8.2 mm, C=8.8 mm). Differences between groups were not significant at 12 months, although the improvements within groups between baseline and 12 months were highly statistically significant (p<0.01). Plaque and BOP levels were low in both groups after treatment.

CONCLUSION

MWF surgery was effective in establishing the periodontal health of sites with advanced disease and this study was unable to detect an additional benefit to using a 25% metronidazole gel.

Periodontal flap surgery with 25% metronidazole gel. (2). Effect on gingival crevicular fluid PGE2

OBJECTIVES

The aim of this study was to examine the effect of periodontal surgery on PGE2 levels in patients treated for advanced adult periodontitis, with and without application of a 25% metronidazole gel over 12 months follow-up.

MATERIAL AND METHODS

The trial employed a randomised controlled, single-blind, parallel arm design on 43 patients with at least 1 pocket probing > or =6 mm with bleeding on probing (BOP).

RESULTS

The results showed that GCF PGE2 levels showed no significant change following surgical therapy despite marked improvements in clinical periodontal health (p=0.653). No significant differences in the reaction of sites to treatment were detected between test and control groups throughout the study (p=0.709). However, PGE2 levels in GCF were significantly higher in experimental sites compared with healthy untreated sites (negative controls) in both surgery only (p= 0.001) and surgery+gel (p=0.023) groups throughout the study.

CONCLUSION

Whilst clear differences were observed between healthy control sites and sites with periodontal breakdown, no effect of treatment on PGE2 levels was discernible in this study.

Comparison of periodontal pocket penetration by conventional and microultrasonic inserts

Recently, 'microultrasonic' instruments have been developed with the aim of improving root-surface debridement. Whilst their reduced tip diameter and modified shape suggests that they may penetrate the periodontal pocket more easily than conventional inserts, there have been few studies investigating their efficacy. The aim of this investigation was therefore to compare the periodontal pocket penetration of a conventional ultrasonic insert (P10 insert--Dentsply) with microultrasonic inserts (Slimline FSI left and right--Dentsply). Efficacy of penetration was assessed by a modification of instrument limit. This modification permitted measurement of the linear % removal of the apical plaque border by image analysis. Debridement was carried out on randomly allocated surfaces of 30 teeth which had been treatment planned for extraction due to periodontitis. One surface on each tooth acted as an untreated control. The results of this study showed that both types of insert were able to reach and debride the apical plaque border, and at all pocket depths assessed. However no significant differences were found between the Slimline insert and the P10 tip. Trends between instruments were observed which suggest that the Slimline insert might more easily penetrate to and debride the apical plaque border in deep pockets, whereas the P10 insert might be more effective in disrupting the apical plaque border in shallow pockets. Future investigations using a larger sample size will be needed to confirm these observations.

Retention, antimicrobial activity, and clinical outcomes following use of a bioerodible tetracycline gel in moderate-to-deep periodontal pockets

This randomized, examiner masked, split mouth study evaluated a new model to test periodontal therapy involving a novel bioerodible copolymer gel containing tetracycline hydrochloride. Responses to the tetracycline gel and untreated control were compared for product tolerance and 3 different measures of effectiveness (drug retention, changes in microbial levels, and clinical status). The test gel was administered by syringe into the periodontal pockets of 18 systemically healthy adult volunteers, each of whom presented with 3 or more sites with 6 mm probing depths. Gingival crevicular fluid samples were used to monitor daily drug levels over 7 days, while clinical responses were assessed at day 30. Overall, the test gel was well-tolerated by all patients. For the 3 effectiveness measures, tetracycline was released throughout the observation period and mean levels exceeded 100 microg/mL over 6 days, statistically significant reductions in selected periodontal pathogens were evident at day 7 but not at day 30, and mean probing depth reductions at test sites were 1.12 mm at 30 days versus 0.36 mm at untreated control sites (P=0.012). The safety profile, longer-term drug retention, antimicrobial activity, and clinical response in this Phase I study suggest that this tetracycline-containing copolymer gel platform may represent a safe and effective bioerodible therapy for periodontitis. The experimental model also shows merit for early phase clinical testing of novel therapeutic agents.

Characterisation of bioadhesives for periodontal and oral mucosal drug delivery

Whilst there is keen interest in developing improved drug delivery devices to the periodontal pocket and oral mucosa, there are few reports which have examined the physical properties of gels and semi-solid formulations which favour retention and bioadhesion in situ. Hydration and rheological properties appear to be of prime importance in this context and this study aimed to correlate the measurement of these properties with observed bioadhesion, both in vitro and in vivo. Three candidate bioadhesives were selected from previous experiments which had used in vitro organ culture models. These were chitosan, xanthan gum and poly (ethylene oxide) aqueous formulations. Hydration rates with various media were determined in specially constructed cells. Rheological properties were measured using a controlled stress rheometer under carefully regulated conditions. These findings were also correlated with in vivo assessments in the periodontal pocket and oral mucosa. The results demonstrated that three formulations with differing bioadhesive properties also possessed widely different physical characteristics. Hydration experiments indicated a direct relationship between the rate of hydration and bioadhesion or retention. Rheological studies suggested that possession of a gel structure could be an important determinant of retention where shear displacing forces are present in vivo, e.g. the oral mucosa. Furthermore, these studies indicated that formulations which could demonstrate resistance to changes in rheological properties on hydration would also favour retention in situ. Physical characterisation therefore appears to have an important place in screening polymeric formulations prior to clinical testing in the periodontal pocket and oral mucosa.

An investigation of bioadhesion for periodontal and oral mucosal drug delivery

Gel delivery vehicles have ideal placement characteristics for periodontal and oral mucosal drug delivery. However, the retention of the vehicle at the site may be of short duration thereby limiting its therapeutic effect. Bioadhesion has received little attention as a means of enhancing vehicle retention in the periodontal pocket and this study aimed to investigate the possible role of this phenomenon to aid oral drug delivery. Chitosan, xanthan gum and poly (ethylene oxide) were selected as potential vehicles from previous in vitro studies, since all 3 had shown good bioadhesive properties. Retention in the periodontal pocket was assessed by means of an insoluble fluorescein marker in 8 patients, and to the oral mucosa by the retention of a small plastic film in 12 subjects. The results showed that fluorescein release from the periodontal pocket was significantly longer for chitosan than for other gels or a water control. In contrast, xanthan gum gave the most prolonged adhesion time on the oral mucosa (153.5 min) followed by poly (ethylene oxide) (89.3 min) and chitosan (42.6 min), and these times were all significantly different from each other (p < 0.05). The results from this study would tend to suggest that the bioadhesive properties of an aqueous gel may be directly related to its retention both in the periodontal pocket and on the oral mucosa. However, other important factors for mucosal adhesion include the patient acceptability of the formulation and the choice of application site.

In vitro assessment of bioadhesion for periodontal and buccal drug delivery

Bioadhesion could significantly improve oral therapeutics for periodontal diseases and mucosal lesions. This project was designed to examine the factors important to prolonged adhesion (adhesion time) in organ culture under standardized conditions. A wide variety of bioadhesives were tested in the model and the effect of mucin was also examined. Whilst many gels adhered for 1-5 h, others (chitosan and Eudispert) showed no retention loss over 4 d. Histologically, chitosan also showed excellent tissue wetting properties. For most materials, however, mucin significantly reduced adhesion times (P < 0.05). In conclusion, the absence of mucin, the control of gel hydration and swelling, and wetting characteristics were identified as key factors for prolonged adhesion.

The role of antibiotics in the treatment of periodontitis (Part 2--Controlled drug delivery)

Since last reviewing the field, controlled release products have made the jump from research to clinical practice. The potential to extend the efficacy of periodontal therapy with such products is exciting, but also needs careful evaluation. This review will look at recent developments and also will examine the eventual place for these products in periodontics.

The role of antibiotics in the treatment of periodontitis. (Part I--Systemic delivery

Controlled release devices containing tetracyclines or metronidazole are now commercially available for use in periodontal pockets. This review, in two parts, evaluates the evidence for and against using antibiotics in the treatment of periodontitis and considers the role for systemic and local delivery. Guidelines for antibiotic usage and recommended regimes are proposed.

Cultural technique for in vitro modelling of prolonged bioadhesion

This paper describes the development of a culture system for bioadhesion testing of gels over prolonged periods. Hamster cheek pouch mucosa was placed on collagen gels or steel mesh supports and submerged in growth medium for periods up to 7 d. Mucosal integrity and morphology were well maintained on mesh supports, but necrosis quickly occurred on collagen gels. Pilot studies with Orabase adhering to the tissue showed no detrimental effects, with the adhesive remaining in place for 4-6 h. It is concluded that the system shows promise for the investigation of prolonged bioadhesion.

Regeneration in periodontics

The regeneration of periodontal tissues and the formation of a new attachment apparatus is now feasible in certain situations. This article reviews the techniques and literature on the subject and discusses the extremely important area of case selection.

Metastatic breast carcinoma presenting with multiple gingival epulides

A case is reported of a young patient with metastases from the breast presenting as rapidly growing gingival epulides. The initial gingival lesion appeared shortly after a bone scan had given no evidence of dissemination of the diagnosed breast cancer. Two further lesions appeared at different sites within 3 weeks.

Controlled drug release in periodontics: a review of new therapies

Controlled drug release formulations are rapidly gaining importance in drug therapy as replacements for conventional systemic dosages. Examples include skin patches for treatment of angina pectoris and motion sickness, eye inserts for glaucoma and implants for prolonged release of contraceptives. This paper will review the current status of periodontal controlled release devices and look at their potential role in periodontal treatment.

The effect of 1% metronidazole gel in routine maintenance of persistent furcation involvement in human beings

The aim of this study was to test adjunctive insertion of 1% metronidazole gel into furcation areas during periodontal maintenance. Ten patients were selected with paired, contralateral, Class II or III furcation involvements that also bled on constant force probing. Bleeding on probing (BOP) and gingival crevicular fluid (GCF) were measured as experimental variables. Plaque was assessed by dark-field microscopy (DFM). Following routine subgingival maintenance of these sites, a syringe was used to insert metronidazole or placebo gels into the furcations. Sites were re-examined 1 and 3 months after baseline. There was little change in either BOP or GCF. Marked longitudinal changes were found by DFM for both experimental and control sites. Experimental sites were not significantly different when compared with controls at the 5% level of probability.