Short-term bactericidal activity of chlorhexidine gel, stannous fluoride gel and amine fluoride gel tested in periodontal pockets

Factorial design of in situ gelling two-compartment systems containing chlorhexidine for the treatment of periodontitis

Periodontitis is one of the most widespread bacterial infectious oral diseases that affects a significant percentage of the population worldwide. Different bacterial strains are responsible for the chronic inflammation and subgingival plaque that could be effectively treated with prolonged exposure to therapeutic levels of antibiotics and antiseptics in the periodontal pockets. Medicated in situ gels of chlorhexidine (CHX), for extended drug release and long-lasting antiseptic effect in the targeted cavities, were prepared in a two-compartment system. One compartment was loaded with sodium alginate solution while other was filled with CHX and calcium solution. The mixing of the solutions during the application resulted in gelation. Two 33 full factorial designs were applied in this study in order to optimize the gel formulation. Initially, the effects of concentration of gelling agent, crosslinker, and pH of the system on the dependent variables such as gel formation and structure characteristics were investigated. Then, the concentration of the crosslinker was optimized. Afterwards, the effect of gelling agent, loading of the drug, and pH of the gel system were correlated with the gel characteristics through another factorial design. Optimized formulations were tested for mucoadhesion, in vitro drug release, and microbiological investigation. Based on the results of the factorial design, mucoadhesiveness, antimicrobial investigation, and drug release, a 4 % alginate composition can be considered optimal. Overall, the optimized in situ periodontal gel was found to be effective with prolonged retention time and desirable outcomes.

The Effect of Hyaluronic Acid Gel on Periodontal Parameters, Pro-Inflammatory Cytokines and Biochemical Markers in Periodontitis Patients

Hyaluronic acid in its various forms shows bacteriostatic, fungistatic, anti-inflammatory, anti-edematous, osteoinductive, and pro-angiogenetic properties. This study aimed to evaluate the effect of subgingival delivery of 0.8% hyaluronic acid (HA) gel on clinical periodontal parameters, pro-inflammatory cytokines (IL-1 beta and TNF-alpha) and biochemical markers of inflammation (C-reactive protein (CRP) and alkaline phosphatase (ALP) enzymes) in patients with periodontitis. Seventy-five patients with chronic periodontitis were divided randomly into three groups (25 in each group): group I received scaling and surface root debridement (SRD) + HA gel; group II received SRD + chlorhexidine gel; and group III received surface root debridement alone. Clinical periodontal parameter measurements and blood samples were collected to estimate pro-inflammatory and biochemical parameters at the baseline before therapy and after two months of therapy. The results show that HA gel has a significant effect on the reduction in clinical periodontal parameters (PI, GI, BOP, PPD, and CAL), IL-1 beta, TNF-alpha, CRP, and ALP after 2 months of therapy as compared to the baseline (p < 0.05) with nonsignificant differences from the CHX group (p > 0.05), except GI (p < 0.05), and significant differences from the SRD group (p < 0.05). Moreover, significant differences were found between the three groups regarding the mean improvements of GI, BOP, PPD, IL-1β, CRP, and ALP. It can be concluded that HA gel has a positive effect on clinical periodontal parameters and improvements in inflammatory mediators similar to chlorhexidine. Therefore, HA gel can be used as an adjuvant to SRD in the treatment of periodontitis.

Comparative Evaluation of Boric Acid Gel versus Chlorhexidine Gel in the Treatment of Chronic Periodontitis: Randomized, Placebo-Controlled Clinical Study

Background:

Over the years, various antimicrobials have been tried and tested in the treatment of periodontitis. Chlorhexidine (CHX) has emerged as the gold standard. In recent years, trend has shifted toward the use of agents with antibacterial, anti-inflammatory, and osteoblastic activity. Boric acid (BA) is one such agent which possess all such properties and thus been evaluated in the treatment of periodontitis.

Aim and Objective:

The aim of the study is to compare and evaluate the efficacy of 0.75% BA gel versus 1% CHX gel as an adjunct to scaling and root planing in patients with chronic periodontitis both clinically and microbiologically.

Materials and Methods:

The present study was a randomized, placebo-controlled clinical trial where 45 systemically healthy patients with chronic periodontitis were included in the study. About 15 patients each were divided into three groups, that is, Group I received BA gel, Group II received CHX gel, and Group III received placebo gel as a local drug delivery agent. Clinical parameters such as gingival index, plaque index, modified sulcus bleeding index, probing pocket depth, and clinical attachment level were evaluated at baseline and 6-month follow-up. Microbiological analysis to check for mixed anaerobic flora was done using subgingival plaque samples at baseline and 3 months after treatment.

Results:

Significant reduction was seen in all clinical parameters in both BA and CHX gel groups as compared to control group (P < 0.05). However, on comparing BA gel group with CHX gel, the results were statistically insignificant (P > 0.05).

Conclusion:

BA gel and CHX gel both were equally effective in improving the clinical and microbiologic parameters in patients with chronic periodontitis when used as a local drug delivery agent.

Adjunctive subgingival application of Chlorhexidine gel in nonsurgical periodontal treatment for chronic periodontitis: a systematic review and meta-analysis

Background

Subgingival applications of chlorhexidine (CHX) gel are commonly used as an adjunct in nonsurgical periodontal treatment (NSPT) for chronic periodontitis (CP). However, there is lack of systematic review and meta-analysis justifying the effects of adjunctive CHX gel on clinical outcomes. The objective of this meta-analysis was to evaluate the efficacy of adjunctive subgingival administration of CHX gel in NSPT compared to NSPT alone for CP.

Methods

An electronic search of four databases and a manual search of four journals were conducted up to August 2019. Only randomized controlled trials reporting on the clinical outcomes of subgingival use of CHX gel adjunct to scaling and root planing (SRP), as compared to SRP alone or with placebo, for at least 3 months were included. Primary outcomes were probing pocket depth (PPD) reduction and clinical attachment level (CAL) gain at 3 and 6 months, when data on at least three studies were obtained.

Results

Seventeen studies were included for qualitative analysis and seven studies for quantitative analysis (four studies for the application of CHX gel adjunct to SRP at selected sites with at least pocket depth ≥ 4 mm and three studies for comparison of full-mouth disinfection (FMD) with subgingival use of CHX gel and full-mouth scaling and root planing (FMSRP). For subgroups, the clinical outcomes between adjunctive use of Xanthan-based CHX gel (XAN-CHX gel) and CHX gel were analyzed. Results indicated a significant improvement of PPD reduction following local adjunctive administration of XAN-CHX gel for SRP at selected sites (MD: 0.15 mm). However, no difference was found in CAL gain. Moreover, no significant difference was observed in PPD and CAL at both 3 and 6 months post-treatment between FMD and FMSRP.

Conclusion

Adjunctive subgingival administration of XAN-CHX gel at individual selected sites in NSPT appears to provide slight benefits in PPD reduction compared to NSPT alone for CP. Due to the lack of high-quality studies, further studies with larger sample sizes and strict standards are needed to confirm the conclusions.

Assessment of the half-life of cationic periodontal pocket irrigation

Background

The concentration and persisting time of antimicrobial agents in the periodontal pockets are important factors for their antimicrobial efficacy. Increased clearance time in the periodontal pocket is a significant criterion for the selection of intrapocket irrigants. The aim of this study was to estimate the clearance time of a cationic agent from the periodontal pocket.

Methods

Thallium-201(Tl-201) was chosen as a tracer to simulate the clearance of cationic substance because of its electrical activity. Twenty patients with periodontitis and probing depths 6 to 9 mm were included in this study. In each patient, 3 Mega Becquerel (MBq) of Tl-201 were inserted into the periodontal pocket. Dynamic imaging was performed and clearance of radioactivity was measured.

Results

Clearance of radioactivity was 67.1 ± 16.9, 83.1 ± 13.9, 90.4 ± 10.4, 93.39 ± 8.0% at 30, 60, 90 and 120 min, respectively. Half-life of wash-out was determined as 20.3 ± 10.2 min.

Conclusion

The results of this study demonstrate that the half-life of the cationic solution applied subgingivally was approximately 20 min and labelling of oral irrigants with radiotracers may be used to determine their clearance in further research.

Development of antiseptic adaptation and cross-adapatation in selected oral pathogens in vitro

There is evidence that pathogenic bacteria can adapt to antiseptics upon repeated exposure. More alarming is the concomitant increase in antibiotic resistance that has been described for some pathogens. Unfortunately, effects of adaptation and cross-adaptation are hardly known for oral pathogens, which are very frequently exposed to antiseptics. Therefore, this study aimed to determine the in vitro increase in minimum inhibitory concentrations (MICs) in oral pathogens after repeated exposure to chlorhexidine or cetylpyridinium chloride, to examine if (cross-)adaptation to antiseptics/antibiotics occurs, if (cross-)adaptation is reversible and what the potential underlying mechanisms are. When the pathogens were exposed to antiseptics, their MICs significantly increased. This increase was in general at least partially conserved after regrowth without antiseptics. Some of the adapted species also showed cross-adaptation, as shown by increased MICs of antibiotics and the other antiseptic. In most antiseptic-adapted bacteria, cell-surface hydrophobicity was increased and mass-spectrometry analysis revealed changes in expression of proteins involved in a wide range of functional domains. These in vitro data shows the adaptation and cross-adaptation of oral pathogens to antiseptics and antibiotics. This was related to changes in cell surface hydrophobicity and in expression of proteins involved in membrane transport, virulence, oxidative stress protection and metabolism.

Necrotrophic growth of periodontopathogens is a novel virulence factor in oral biofilms

The oral use of antimicrobial agents embedded in toothpastes and mouth rinses results in an oral microbial massacre with high amounts of dead bacteria in close proximity to few surviving bacteria. It was hypothesized that this provides the surviving pathogenic bacteria a large amount of dead microbial biomass as a nutritional source for growth (necrotrophy). This study demonstrated the necrotrophic growth of periodontal pathogens in the presence of different dead oral species. In addition, the presence of dead bacteria resulted in an outgrowth of several periodontal pathogens in complex multi-species biofilms. Additionally, upon contact with dead oral bacteria, virulence genes of P. intermedia and P. gingivalis were up-regulated (necrovirulence). This resulted in a more pronounced epithelial cytotoxicity (necrotoxicity). These findings indicate that presence of dead bacteria induce necrotrophy, necrovirulence and necrotoxicity in several oral pathogens.

Different methods for subgingival application of chlorhexidine in the treatment of patients with chronic periodontitis

OBJECTIVE

The aim of this study was to evaluate clinical efficacy of different chlorhexidine gluconate (CHX) preparations applied subgingivally as an adjunct to scaling and root planing (SRP).

MATERIAL AND METHODS

A total of 120 periodontal pockets was included in this randomized, controlled, split mouth designed study. According to protocols used in treatment, periodontal pockets were assigned to experimental and control groups as follows: CHX solution as an addition to SRP versus control SRP group; CHX gel as an addition to SRP versus control SRP; CHX chip as an addition to SRP versus control SRP group. Following clinical parameters were recorded at baseline, one and three months after the baseline: plaque index (PI), probing pocket depth (PPD), bleeding index (BI) and clinical attachment level (CAL).

RESULTS

The most significant improvements were found concerning PI in CHX solution with SRP and CHX gel with SRP groups over controls at one month recall, as well as concerning BI and PPD in CHX chip with SRP group over SRP alone at three-month recall.

CONCLUSION

Results of this study favour combination therapy using CHX chip as an adjunct to SRP due to greater improvements in BI and PPD compared to those obtained by SRP alone in the treatment of chronic periodontitis.

Microbiota-based Signature of Gingivitis Treatments: A Randomized Study

Plaque-induced gingivitis can be alleviated by various treatment regimens. To probe the impacts of various anti-gingivitis treatments on plaque microflora, here a double blinded, randomized controlled trial of 91 adults with moderate gingivitis was designed with two anti-gingivitis regimens: the brush-alone treatment and the brush-plus-rinse treatment. In the later group, more reduction in both Plaque Index (TMQHI) and Gingival Index (mean MGI) at Day 3, Day 11 and Day 27 was evident, and more dramatic changes were found between baseline and other time points for both supragingival plaque microbiota structure and salivary metabonomic profiles. A comparison of plaque microbiota changes was also performed between these two treatments and a third dataset where 50 subjects received regimen of dental scaling. Only Actinobaculum, TM7 and Leptotrichia were consistently reduced by all the three treatments, whereas the different microbial signatures of the three treatments during gingivitis relieve indicate distinct mechanisms of action. Our study suggests that microbiota based signatures can serve as a valuable approach for understanding and potentially comparing the modes of action for clinical treatments and oral-care products in the future.

A clinical, microbiological and immunological comparison between subgingival irrigation with Dentol and chlorhexidine in advanced periodontitis

INTRODUCTION

The purpose of this study was to compare the clinical, microbiological and immunological effects of subgingival irrigation with Dentol(™) and 0.2% chlorhexidine in human advanced periodontitis.

MATERIAL AND METHODS

Twenty cases of advanced periodontitis patients were randomly treated either with Dentol(™) (as test) or 0.2% chlorhexidine (as control) every other day for 29 days after primary scaling, root planing and oral hygiene instruction. Pocket depth (PD), bleeding on probing (BOP) and plaque index (PI) were considered as clinical parameters. Total counts of aerobic and anaerobic bacteria were measured in subgingival plaque. At the end, concentrations of TNF-α and IL-1β in gingival crevicular fluid were measured as inflammatory markers.

RESULTS

PD and BOP decreased in both groups on the 29(th) day and two weeks afterward. PI did not show any statistical difference either within or among groups (p > 0.05). Results indicate that both chlorhexidine and Dentol(™) diminished total count of subgingival anaerobic bacteria significantly (p < 0.05). Total count of subgingival aerobic bacteria increased in both groups, but the differences between the two groups were statistically significant in favour of Dentol(™) (p < 0.05). The level of IL-1β in the crevicular fluid was reduced in both groups but it was more significant in the test group (p < 0.05). The TNF-a level decreased in both groups but the statistical difference between the two groups was negligible (p > 0.05).

CONCLUSIONS

Subgingivally irrigation with Dentol(™), containing 0.02% carvacrol, every other day for 29 days is equally or more effective than 0.2% chlorhexidine in reducing clinical and immunological inflammatory indices.

An 8-week, randomized, controlled, clinical study of the use of a 0.1% chlorhexidine mouthwash by chronic periodontitis patients

AIM

  To evaluate the efficacy of a 2-week administration of a 0.1% chlorhexidine mouthwash in the short-term treatment of chronic periodontitis patients and the impact of this product when administered twice by pocket irrigation.

METHODS

  Sixty patients were enrolled in a single-centre, placebo-controlled, randomized study with the blind allocation of product to two parallel groups. Clinical assessments were performed, and samples from six selected subgingival sites were collected for microbial analysis by culture at baseline, D15 and D56. Three of the six sites were randomly selected and were treated by subgingival irrigation with the same 0.1% chlorhexidine product at D0 and D7. A subsequent statistical analysis was performed using the paired Student's t-test and Wilcoxon rank sum test for within-group analyses; analysis of variance and the Kruskall-Wallis test were used for between-group analyses.

RESULTS

  Two-week treatment with a 0.1% chlorhexidine mouthwash slightly reduced the gingival inflammation associated with periodontitis. We observed a significant decrease in Gram-negative, facultative anaerobes and micro-aerophiles, and a significant increase in Gram-positive cocci. No increase in the treatment effect was demonstrated by irrigation of the periodontal pockets.

CONCLUSION

  The 0.1% chlorhexidine mouthwash showed limited beneficial effects in the treatment of periodontitis patients.

Nonsurgical mechanical treatment strategies for periodontal disease

The comparison of the efficacy of surgical and nonsurgical procedures revealed that scaling and root planing alone or in combination with flap procedures are effective methods for the treatment of chronic periodontitis. Also, the consistent message is that in treating deep pockets, open-flap debridement results in greater probing pocket depth reduction and clinical attachment gain than nonsurgical modalities. Nonsurgical modalities in shallower pockets consistently involve less post-therapy recession and are clearly recognized as being more conservative. Research is still needed on the clinical benefit of the granulation tissue removal that is a feature of periodontal surgical therapy and, to a lesser extent, occurs through indirect trauma in nonsurgical therapy.

A Systematic Review on the Effects of the Chlorhexidine Chip When Used as an Adjunct to Scaling and Root Planing in the Treatment of Chronic Periodontitis

BACKGROUND

Several local antimicrobial agents, such as a bioabsorbable chlorhexidine chip, have been developed to enhance the outcome of non-surgical periodontal therapy.

METHODS

Electronic (MEDLINE and Cochrane Oral Health Group Specialized Trials Register) and manual searches were performed to detect studies concerning the use of the chlorhexidine chip as an adjunct to scaling and root planing in the treatment of chronic periodontitis. Only full-text randomized controlled trials published in English up to June 2005 were included.

RESULTS

Five studies were finally selected following independent screening by two reviewers. Due to considerable heterogeneity in study design, a qualitative data analysis was performed. Multicenter studies have indicated significantly higher pocket reductions and clinical attachment gains following a combination of mechanical debridement and repeated chlorhexidine chip administration in comparison to scaling and root planing alone. However, some recent studies failed to confirm the additional value of the chlorhexidine chip. A number of interstudy disparities with respect to methodological quality and study design may account for this lack of accordance.

CONCLUSIONS

The clinical and microbiological data currently available on the chlorhexidine chip are limited and conflicting. More research is needed to elucidate the additional value of the chlorhexidine chip when used as an adjunct to scaling and root planing.

A Systematic Review on the Effects of Subgingival Chlorhexidine Gel Administration in the Treatment of Chronic Periodontitis

BACKGROUND

Since scaling and root planing are not always successful, predominantly when access to periodontal defects is compromised, various antimicrobial agents as adjuncts have been suggested to enhance their efficacy. Gel vehicles delivering chlorhexidine (CHX) have become available and tested for these indications.

METHODS

An electronic (MEDLINE and Cochrane Oral Health Group Specialized Trials Register) and manual search were made to detect studies concerning the use of chlorhexidine gels as a single measure of treatment and as an adjunct to scaling and root planing. Only full-text randomized controlled trials published in English up to January 2005 were included.

RESULTS

Eight studies were finally selected. Due to considerable heterogeneity in study design and outcome variables measured a qualitative data analysis was performed. There is evidence that subgingival chlorhexidine gel administration as a monotherapy temporarily reduces bleeding tendency on probing; a clinical effect coinciding with relevant microbiological changes described in all but one study. To what extent chemical effects contribute to these changes appears to be related to the frequency of gel administration. There seem to be little to no data indicating that the treatment outcome of scaling and root planing will benefit from the adjunctive subgingival administration of a CHX gel.

CONCLUSION

The limited data currently available on the effects of subgingival chlorhexidine gel application do not justify its use in the treatment of chronic periodontitis.

Quadrant root planing versus same-day full-mouth root planing. I. Clinical findings

OBJECTIVES

The aim of this study was to test the hypothesis that same-day full-mouth scaling and root planing (FM-SRP) resulted in greater clinical improvement compared to quadrant scaling and root planing (Q-SRP) in chronic periodontitis patients over a period of 6 months.

MATERIAL AND METHODS

Forty patients were recruited into this study. Subjects were randomised into two groups. The FM-SRP group received full-mouth scaling and root planing completed within the same day, while the Q-SRP group received quadrant root planing at 2-weekly intervals over four consecutive sessions. Whole-mouth clinical measurements were recorded with a manual periodontal probe at baseline (BAS) and at reassessment 1 (R1) (approximately 6 weeks after the completion of therapy), and at reassessment 2 (R2) (6 months after the initiation of therapy). Selected site analyses were performed on the deepest site in each quadrant before and after therapy (R1 and R2) and clinical indices were recorded with an electronic pressure sensitive probe. In addition, during the active phase of treatment clinical data were collected at 2-weekly intervals from the remaining untreated quadrants in the Q-SRP group only.

RESULTS

Both therapies resulted in significant improvements in all clinical indices both at R1 and R2. A continuous clinical improvement was seen for both treatment groups during the experimental period, which reached peak levels at 6 months (DeltaPD=1.8 mm, DeltaCAL=1.1 mm, p<0.001; PD: pocket depth; CAL: clinical attachment level). The selected-site analysis revealed no significant differences in any clinical index between the two treatment groups at R2 (DeltaPD=2.8 mm, DeltaRAL=1.1 mm; RAL: relative attachment level). At the selected sites, the analysis of the deep pockets (>7 mm) showed a significantly greater gain in RAL for the FM-SRP group compared to the Q-SRP group at R2 (p<0.05). The results of this analysis however, should be interpreted with care due to the small number of deep pockets. Data from the Q-SRP group provided an insight into how treated and untreated quadrants responded during the initiation of plaque control measures. There were significant reductions in PD, suppuration (SUP), modified gingival index (MGI) and plaque index (PI) in the remaining untreated quadrants in the Q-SRP group during the initial phase of treatment (p<0.05), while minimum changes in RALs and bleeding on probing (BOP) occurred. Nevertheless, the improvement in PD was clearly inferior to that seen after scaling and root planing.

CONCLUSION

Following both therapeutic modalities, there were marked clinical improvements at both R1 and R2 (6 months) from baseline. The current study, in contrast to previous findings, failed to show that FM-SRP is a more efficacious periodontal treatment modality compared to Q-SRP. However, both modalities are efficacious and the clinician should select the treatment modality based on practical considerations related to patient preference and clinical workload.

Effectiveness of stannous fluoride and calcium hydroxide against Enterococcus faecalis

The objective of this study was to evaluate the antimicrobial activity of stannous fluoride, calcium hydroxide, or the two in combination against Enterococcus faecalis. Fifteen Mueller-Hinton agar plates were used to conduct a disc diffusion susceptibility test. The plates were inoculated with E. faecalis. The groups tested were: (a) stannous fluoride (Stanimax); (b) calcium hydroxide; and (c) a combination of stannous fluoride and calcium hydroxide. Three filter paper discs, each soaked with one of the groups, were placed along with an antibiotic control (ampicillin) on each agar plate. The plates were then incubated at 37 degrees C. The zones of inhibition were measured at 24 and 48 h. One-way ANOVA revealed a statistically significant difference (p < 0.05) between the three groups. Stannous fluoride displayed the widest zone (1.7 mm), followed by the combination of stannous fluoride and calcium hydroxide (1.1 mm), whereas calcium hydroxide by itself displayed a minimal zone of inhibition (0.05 mm).

Amine fluoride gel affects the viability and the generation of superoxide anions in human polymorphonuclear leukocytes: an in vitro study

Amine hydrofluorides are widely used to prevent caries. As an acidulated gel, they were also studied for their applicability to reduce pathogenic bacteria in periodontal pockets. We assessed the toxicity of this pharmaceutical amine hydrofluoride preparation on human polymorphonuclear leukocytes in vitro by measuring Trypan blue exclusion and the generation of superoxide anions (O2) by the chemotactic peptide N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP) after a 3-min contact with gel. Depending on the experimental conditions, gel dilutions up to 1.3 x 10(4) resulted in an increase in Trypan blue-colored cells and liberation of beta-glucuronidase. Dilutions between 3 x 10(4) and 1 x 10(5) augmented the fMLP-mediated O2- generation, which could be prevented by Ca2+ chelation with BAPTA-AM (1,2'-bis (o-aminophenoxyethane-N.N.N'.N'-tetraacetic acid tetra (acetoxymethyl) ester) and ethyleneglycoltetraacetic acid (EGTA) or inhibition of protein kinase C (PKC) with staurosporine and bisindolylmaleimide I. respectively. Compared with data published on the minimal inhibitory concentration for periodontal pathogenic bacteria, the cytotoxicity of amine hydrofluorides on eukaryotic cells is much greater and thus of consequence for their clinical use.

Full-mouth therapy versus individual quadrant root planning: a critical commentary

BACKGROUND

This commentary compares the abilities of full-mouth disinfection (FDIS), full-mouth root planing (FRP), and partial-mouth disinfection (PDIS) to improve periodontal health. FDIS consists of 4 quadrants of root planing completed within 24 hours with adjunctive chlorhexidine therapies (e.g., rinsing, subgingival irrigation, tongue brushing). FRP denotes 4 quadrants of root planing performed within 24 hours, and PDIS refers to root planing individual quadrants of the dentition, spaced 2 weeks apart. A basic premise of administering full-mouth therapy (FDIS or FRP) is to eliminate or reduce bacterial reservoirs within the oral cavity that could inhibit optimal healing of treated sites or cause periodontal disease initiation or progression.

METHODS

Controlled clinical trials that compared the abilities of PDIS and full-mouth root planing with and without adjunctive chlorhexidine chemotherapy to alter periodontal status were reviewed.

RESULTS

Several studies conducted at one treatment center indicated that FDIS and FRP attained greater therapeutic improvements than PDIS with respect to decreasing probing depths (PD), gaining clinical attachment (CAL), diminishing bleeding upon probing, and reducing the subgingival microflora. However, the magnitude of PD reductions and gains of clinical attachment must be carefully interpreted, because initial PD measurements were usually determined after scaling and root planing, which may have caused the results to be overstated. Furthermore, in studies that addressed the utility of FDIS, it was not possible to determine if benefits induced beyond PDIS were due to FRP or administration of multifaceted intraoral chlorhexidine treatments ora combination of both therapies. One investigation that had protocol limitations indicated that similar results were attained by FRP with and without adjunctive chemotherapy. In contrast, recent studies from 2 other treatment centers indicated that there were no significant differences when the efficacy of quadrant-by-quadrant root planing was compared to FRP or FDIS with regard to PD reduction, gains of clinical attachment, and impact on the magnitude and quality of the immune response. POSSIBLE CLINICAL IMPLICATIONS: Conceptually, full-mouth therapy (FRP or FDIS) could reduce the number of patient visits and facilitate more efficient use of treatment time. In addition, there appears to be no major adverse reactions to full-mouth root planing with or without adjunctive chemotherapy. However, small study populations and non-corroborating data from different treatment centers indicate that additional randomized clinical trials are needed to determine if full-mouth therapy provides clinically relevant improvements beyond PDIS.

The intra-oral translocation of periodontopathogens jeopardises the outcome of periodontal therapy

BACKGROUND

Although periodontitis has a multi-factorial aetiology, the success of its therapy mainly focuses on the eradication/reduction of the exogenous/endogenous periodontopathogens. Most of the species colonise several niches within the oral cavity (e.g. the mucosae, the tongue, the saliva, the periodontal pockets and all intra-oral hard surfaces) and even in the oro-pharyngeal area (e.g., the sinus and the tonsils).

METHODS

This review article discusses the intra-oral transmission of periodontopathogens between these niches and analyses clinical studies that support the idea and importance of such an intra-oral translocation.

RESULTS AND CONCLUSIONS

Based on the literature, the oro-pharyngeal area should indeed be considered as a microbiological entity. Because untreated pockets jeopardise the healing of recently instrumented sites, the treatment of periodontitis should involve "a one stage approach" of all pathologic pockets (1-stage full-mouth disinfection) or should at least consider the use of antiseptics during the intervals between consecutive instrumentations, in order to prevent a microbial translocation of periodontopathogens during the healing period. For the same reason, regeneration procedures or the local application of antibiotics should be postponed until a maximal improvement has been obtained in the remaining dentition. This more global approach offers significant additional clinical and microbiological benefits.

In vitro studies and modeling of a controlled-release device for root canal therapy

Endodontic disease is caused primarily by bacteria that interact with periradicular host tissues. Therefore, treatment of endodontic disease aims at the exclusion of bacteria from the root canal system. This work focused on in vitro studies and modeling of a controlled-release device for delivering antimicrobial agents in root canals. A cylindrical, needle-shaped device was prepared consisting of a matrix core and a polymer coating, loaded with 30-45% chlorhexidine (CHX). The composition of the core, a blend of water-permeable polymers, and the thickness of the coating were tailored to impart various release rates. A relatively steady release rate for over 40 days after an initial burst was achieved using a formulation for long-term release, which is desirable for establishing and maintaining the necessary therapeutic levels. Mathematical models were developed for both in vitro and in vivo drug release into a liquid of limited volume, taking into account a moving boundary of the dispersed drug and a time-dependent boundary condition. A concentration-dependent effective diffusion coefficient was used to count increased porosity as the solid drug had dissolved. The finite element method and computer programs were applied to solve the differential equations and predict the in vitro and in vivo release kinetics. The model prediction agreed well with the in vitro experimental data and provided guidance for designing the device for in vivo release in root canals. The result of in vitro antimicrobial tests, performed using a bovine tooth model, suggested that the device was effective in reducing growth of microbes.

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

BACKGROUND

Previous multi-center trials demonstrated the efficacy of a biodegradable chlorhexidine-gelatin chip (CHX) in reducing probing depth in patients with periodontitis. The present study utilized a subset of subjects from the parent study to determine if the CHX chip was effective in maintaining alveolar bone over a 9-month period.

METHODS

Forty-five subjects with at least four 5 to 8 mm pockets, stratified by smoking status, were enrolled in this double-blind controlled, placebo-controlled trial. Control groups received either placebo chip plus scaling and root planing (SRP) or SRP alone. Test group subjects received active CHX chip or SRP alone (to maintain the blind). Standardized radiographs were taken for quantitative digital subtraction radiography at baseline and 9 months.

RESULTS

At 9 months, 15% of SRP treated subjects experienced loss of bone in 1 or more sites, no subject treated with active chip plus SRP lost bone (P <0.01). At 9 months, significant differences in the change in probing depth and clinical attachment levels favoring the active chip over SRP alone or SRP plus CHX chip were also observed (P <0.05).

CONCLUSIONS

These data indicate that the CHX chip, when used as an adjunct to scaling and root planing, significantly reduces loss of alveolar bone.

One stage full- versus partial-mouth disinfection in the treatment of chronic adult or generalized early-onset periodontitis. I. Long-term clinical observations

BACKGROUND

A standard treatment strategy for periodontal infections often consists of 4 consecutive sessions of scaling and root planing (per quadrant, at 1- to 2-week intervals), without proper disinfection of the remaining intra-oral niches for periodontopathogens. This could theoretically lead to a reinfection of previously disinfected pockets by bacteria from an untreated region/niche. This study aimed to investigate, over an 8-month period, the clinical benefits of a one stage full-mouth disinfection in the control of severe periodontitis.

METHODS

Sixteen patients with early-onset periodontitis and 24 patients with severe adult periodontitis were randomly assigned to test and control groups. The control group was scaled and root planed, per quadrant, at 2-week intervals and given standard oral hygiene instructions. A one stage full-mouth disinfection (test group) was sought by scaling and root planing the 4 quadrants within 24 hours in combination with the application of chlorhexidine to all intra-oral niches for periodontopathogens. Besides oral hygiene, the test group also rinsed twice daily with a 0.2% chlorhexidine solution and sprayed the tonsils with a 0.2% chlorhexidine spray, for 2 months. The plaque index, gingival index, probing depth, bleeding on probing, gingival recession, and clinical attachment level were recorded at baseline and at 1, 2, 4, and 8 months afterwards.

RESULTS

The one stage full-mouth disinfection resulted, in comparison to the standard therapy, in a significant (P <0.001) additional probing depth reduction and gain in attachment up to 8 months. For initial pockets > or =7 mm, the "additional" probing depth reduction at the 8 month follow-up was 1.2 mm for single-rooted and 0.9 mm for multi-rooted teeth, with corresponding additional gains in attachment of 1.0 mm and 0.8 mm, respectively. The additional improvements were observed for all subgroups (adult periodontitis, generalized early-onset cases, smokers), with the largest differences in the non-smoking adult periodontitis patients.

CONCLUSIONS

These findings suggest that a one stage full-mouth disinfection results in an improved clinical outcome for the treatment of chronic adult or early-onset periodontitis as compared to scaling and root planing per quadrant at 2-week intervals.

Subgingival controlled release of antimicrobial agents in the treatment of periodontal disease

Local drug delivery of antimicrobics by sustained release delivery systems can be used to treat periodontal disease. Advantages of these systems may include biodegradation of the system, maintaining high levels of antibiotic in the gingival crevicular fluid (GCF) for a sustained period of time and ease of use with high patient acceptance. This review will identify human in vivo clinical and microbiological studies. Sustained release formulations, application methods, clinical results and microbiological effects are discussed.

The effect of a one-stage full-mouth disinfection on different intra-oral niches. Clinical and microbiological observations

A treatment for periodontal infections often consists of consecutive rootplanings (per quadrant, at a 1- to 2-week interval), without a proper disinfection of the remaining intra-oral niches (untreated pockets, tongue, saliva, mucosa and tonsils). Such an approach, could theoretically lead to a reinfection of previously-treated pockets. The present study aims to examine the effect of a full-mouth disinfection on the microbiota in the above-mentioned niches. Moreover, the clinical benefit of such an approach was investigated. 16 patients with severe periodontitis were randomly allocated to a test and a control group. The patients from the control group were scaled and rootplaned, per quadrant, at 2-week intervals and obtained oral hygiene instructions. The patients from the test group received a full-mouth disinfection consisting of: scaling and rootplaning of all pockets in 2 visits within 24 h, in combination with tongue brushing with 1% chlorhexidine gel for 1 min, mouth rinsing with a 0.2% chlorhexidine solution for 2 min and subgingival irrigation of all pockets (3x in 10 min) with 1% chlorhexidine gel. Besides oral hygiene, the test group rinsed 2x daily with 0.2% chlorhexidine and sprayed the tonsils with a 0.2% chlorhexidine for 2 months. Plaque samples (pockets, tongue, mucosa and saliva) were taken at baseline and after 2 and 4 months, and changes in probing depth, attachment level and bleeding on probing were reported. The full-mouth disinfection resulted in a statistically significant additional reduction/elimination of periodontopathogens, especially in the subgingival pockets, but also in the other niches. These microbiological improvements were reflected in a statistically-significant higher probing depth reduction and attachment gain in the test patients. These findings suggest that a disinfection of all intra-oral niches within a short time span leads to significant clinical and microbiological improvements for up to 4 months.

Trial of chlorhexidine gluconate for fungal corneal ulcers

AIMS

Suppurative corneal ulcers due to filamentous fungi are a serious and intractable problem in many tropical developing countries. In vitro studies and a small pilot study have shown that chlorhexidine gluconate is effective. The aim was to establish the optimum concentration which would be appropriate to use in a larger randomized clinical trial.

METHODS

A masked randomized clinical trial of three concentrations of chlorhexidine compared with natamycin 5% was carried out in consecutive patients with established corneal ulcers shown by microscopy to contain fungal hyphae and later proven to be culture positive. Topical treatments were applied 1/2-hourly to 2-hourly for up to 5 days, with reduced frequency thereafter, and all patients were re-assessed at 21 days.

RESULTS

Of 60 patients entered in the trial, 2 were lost to follow-up, and 12 were classified as 'severe' with little prospect of recovery. At 5 days the response was related to the concentration of chlorhexidine, with 0.2% giving the best results. Compared with the response to natamycin as the referent, the relative efficacy was 1.17 with chlorhexidine 0.05%, 1.43 with 0.1%, and 2.00 with 0.2%. The superiority of 0.2% chlorhexidine over natamycin was statistically significant (relative efficacy 2.20, p = 0.043) in patients not having had prior antifungal treatment.

CONCLUSIONS

This preliminary study justifies further trials of chlorhexidine as a primary treatment for fungal corneal ulcers in circumstances where specific antifungal agents are not available.

Clinical and microbiological effects of subgingival antimicrobial irrigation with citric acid as evaluated by an enzyme immunoassay and culture analysis

The purpose of the present study was to compare an enzyme immunoassay with culture samples from untreated and non-surgically treated periodontal pockets and to assess the clinical and microbiological effects of citric acid irrigation as a supplement to scaling and root planing. The enzyme immunoassay used in this study is a chairside diagnostic tool aimed at identifying the presence of P. gingivalis, P. intermedia, and A. actinomycetemcomitans. Six sites with pocket depths > or = 6 mm in each of 16 patients were monitored for 24 weeks using clinical and microbiological parameters. In two out of the six sites, scaling and root planing was supplemented with subgingival citric acid irrigation of the pocket after completion of the mechanical treatment. The sensitivity of the immunoassay in relation to culture was calculated to 85.5% and the specificity to 90.2%. The immunoassay corresponded to a detection level of 10(4) as estimated by culture. Sites treated with a combination of scaling and irrigation with citric acid demonstrated a similar healing pattern as sites treated with scaling and root planing alone. The profile of the marker bacteria was almost parallel for the two groups. The results of this investigation thus indicated that the immunoassay can be used as a screening tool for selected periodontal pathogens and that adjunctive irrigation with citric acid has no measurable clinical or microbiological effects.

One-stage Full-mouth Disinfection to Overcome Intra-oral Transmission of Periodontopathogens

The oral cavity offers a range of different niches where periodontopathogens can adhere and survive (e.g. the mucosa, the tongue, the tonsils, the saliva and all intra-oral hard surfaces such as teeth, dentures, oral implants). Transmission of bacteria from one niche to another is likely to occur. Recent studies, for example, illustrated that initially sterile abutments of oral implants were rapidly colonized by bacteria from the subgingival environment around teeth. This transmission of bacteria can occur spontaneously via the saliva, or by means of oral hygiene aids and/or dental instruments. Such an intra-oral transmission, if it occurs at a high speed, could jeopardize the outcome of periodontal therapy. To overcome a bacterial transmission, a 'one-stage full-mouth disinfection' was recently introduced for the treatment of periodontal infections. This new treatment strategy resulted in significant clinical and microbiological improvements when compared with the standard sequential treatment.

Full- versus partial-mouth disinfection in the treatment of periodontal infections. Long-term clinical observations of a pilot study

A classical treatment for chronic adult periodontitis consists of four to six consecutive sessions of scaling and root planing at a 1- to 2-week interval. Such a so-called "quadrant or sextant therapy" might result in a reinfection of a previously disinfected area by bacteria from an untreated region. The purpose of this study was to investigate, over an 8-month period, the clinical benefits of full-mouth disinfection within a 24-hour period in the control of chronic periodontitis. Ten adult patients with advanced chronic periodontitis were randomly assigned to a test and a control group. The control group received the standard scheme of initial periodontal therapy, consisting of scaling and root planing of the four quadrants was performed within 24 hours and immediately followed by a thorough supra- and subgingival chlorhexidine application to limit any transfer of bacteria. The latter involved tongue brushing with a 1% chlorhexidine gel for 60 seconds, mouthrinsing with a 0.2% chlorhexidine solution twice for 60 seconds, repeated subgingival irrigation of all pockets with a 1% chlorhexidine gel (3 times within 10 minutes), and mouthrinsing twice daily with a 0.2% chlorhexidine solution during 2 weeks. In addition, both groups received thorough oral hygiene instructions. The plaque index, gingival index, probing depth, gingival recession, and bleeding on probing were recorded prior to professional cleaning and at 1, 2, 4, and 8 months afterwards. Although the test group scored higher plaque indices than the control group, especially at months 2 and 4, the gingival index and bleeding tendency showed similar improvements with time. However, when the gingival/plaque ratio was considered, the latter was lower in the test group at all follow-up visits. For pockets > or = 7 mm, full-mouth disinfection showed a significantly (P = 0.01) higher reduction in probing depth at each follow-up visit with, at month 8, a reduction of 4 mm (from 8 mm to 4 mm), in comparison to 3 mm (from 8 mm to 5 mm) for the classical therapy. The increase in gingival recession in the full-mouth disinfection group remained below 0.7 mm, while in the control group it reached 1.9 mm after 8 months. This resulted in a gain of clinical attachment level of 3.7 mm for the test group versus 1.9 mm for the control group. A radiographical examination also indicated a superior improvement for the test group when compared to the control group. This pilot study suggests that a full-mouth disinfection in one day results in an improved clinical outcome in chronic periodontitis as compared to scalings per quadrant at 2-week intervals over several weeks.

Full- versus partial-mouth disinfection in the treatment of periodontal infections. A pilot study: long-term microbiological observations

A standard periodontal treatment consists of 4 to 6 scalings and rootplanings at a 1- to 2-week interval, which allows reinfection of a previously disinfected area before completion of the treatment. The present pilot study aims to examine the microbiological long-term effects of a full-mouth disinfection. 10 patients with advanced chronic periodontitis were randomly allocated to a test and control group. The patients from the control group received scaling and rootplaning and oral hygiene instructions at a 2-week interval. The full-mouth disinfection (test group) consisted of a full-mouth scaling and rootplaning in 2 visits within 24 h in combination with: tongue brushing with 1% chlorhexidine gel for 1 min, mouth rinsing with 0.2% chlorhexidine solution for 2 min and subgingival irrigation of all pockets (3x in 10 min) with 1% chlorhexidine gel. The patients of the test group were instructed to rinse 2x daily with 0.2% chlorhexidine. Plaque samples were taken at baseline and after 1, 2, 4 and 8 months. Differential phase-contrast microscopy showed a significantly larger reduction of spirochetes and motile organisms in the test group up to month 2 for the single-rooted and up to month 8 for the multi-rooted teeth. Furthermore, the culture data supported the effectiveness of the new treatment strategy. In both groups, the number of anaerobic CFU decreased 1 log around single- and 0.5 log around multi-rooted teeth. The number of anaerobic CFU remained low in the test group, in contrast to the control group. At 1 month, the test group harboured a significantly (p<0.01) lower proportion of pathogenic organisms, but this difference disappeared with time. Moreover, the test sites showed a significantly higher (p<0.02) increase in the proportion of beneficial micro-organisms up to 4 months. These findings suggest that a full-mouth disinfection leads to a significant microbiological improvement up to 2 months, which could be consolidated, although not significant, for the next 6 months.

Full- vs. partial-mouth disinfection in the treatment of periodontal infections: short-term clinical and microbiological observations

In a standard periodontal treatment strategy with consecutive root planings (per quadrant at a one- to two-week interval), re-infection of a disinfected area might occur before completion of the treatment. This study examines, both clinically and microbiologically, whether a full-mouth disinfection within 24 hours significantly improves the outcome of periodontal treatment. Ten patients with advanced chronic periodontitis were randomly allocated to a test and a control group. The patients from the control group received scalings and root planings as well as oral hygiene instructions per quadrant at two-week intervals. Full-mouth disinfection in the test group was sought by the removal of all plaque and calculus (in two visits within 24 hours). In addition, at each of these visits, the tongue was brushed with a 1% chlorhexidine gel for one min and the mouth rinsed with a 0.2% chlorhexidine solution for two min. Furthermore, subgingival chlorhexidine (1%) irrigation was performed in all pockets. The recolonization of the pockets was retarded by oral hygiene and 0.2% chlorhexidine rinses during two weeks. The clinical parameters were recorded, and plaque samples were taken from the right upper quadrant at baseline and after one and two months. The test group patients showed a significantly higher reduction in probing depth for deep pockets at both follow-up visits (p < 0.05). At the one-month visit, differential phase-contrast microscopy revealed significantly lower proportions of spirochetes and motile rods in the test group (p = 0.01). Culturing showed that the test group harbored significantly fewer pathogenic organisms at one month (p = 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

DNA probe analyses of the survival of selected periodontal pathogens following scaling, root planing, and intra-pocket irrigation

This clinical study evaluated the survival rates of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia in periodontal pockets following scaling and root planing and intra-pocket irrigation with antimicrobial agents in patients with moderate and severe periodontitis. The number of target organisms was determined utilizing DNA probes. Adult periodontitis patients were selected on the basis that the subgingival flora contained at least one of the target organisms. Forty-eight (48) inflamed pockets > or = 5 mm in depth with probing attachment loss and containing at least one of the target species were then selected in 7 adult patients who harbored these bacteria. Following baseline clinical and bacterial examination, all patients received thorough scaling and root planing. In addition, 1 or 2 teeth in each patient which harbored the target flora at baseline were randomly assigned to each of the following 4 treatment modalities: 1) control group, no irrigation; 2) saline group, irrigation with 2 cc of physiologic saline; 3) tetracycline group, irrigation with 2 cc of aqueous tetracycline hydrochloride, 50 mg/ml (5%); and 4) chlorhexidine group, irrigation with 2 cc 0.12% chlorhexidine. All selected sites (5 to 8 per patient) were nonadjacent teeth. Clinical parameters and microbial analysis were recorded again at one week, and one month post-irrigation. The survival rate of the target microorganisms was determined and the effect of irrigation with antimicrobial agents on this microflora was compared with the control groups (1 and 2).(ABSTRACT TRUNCATED AT 250 WORDS)

The role of subgingival irrigations in the treatment of periodontitis

While the efficacy of oral irrigations with antimicrobial agents on the clinical and microbial parameters of gingivitis is well established, the study of the efficacy of intrapocket irrigants on periodontitis has yielded conflicting and inconclusive results regarding both clinical and microbiological parameters. The overall goal of this review paper is to summarize the available information on the efficacy of intrapocket irrigation in the treatment of patients with periodontitis. The following topics are addressed: 1) the penetrability of the irrigant; 2) pocket irrigation without scaling and root planing; 3) professional pocket irrigation following scaling and root planing; 4) irrigations between recalls; and 5) safety of intrapocket irrigation. Single irrigation of periodontal pockets for short periods of time before or after scaling and root planing has limited effects on periodontal healing. However, continuous irrigation of the periodontal lesion with agents such as povidone iodine during thorough scaling and root planing, such as that carried out under local anesthesia, has promise as an antimicrobial adjunct in periodontal therapy.

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

The committee screened several hundred articles, citing 518 published papers. Some are present quality in research, others provide clinical interest, and some are identified as misleading. New techniques in pulp physiology and pathology are reported. Laser use and techniques in prevention, restorative dentistry, and materials use are reported. Epidemiology of selected diseases and the results of various formulations for treatment are cited. Diagnosis of craniomandibular dysfunction is well represented as well as references to literature reviews and other sophisticated scientific investigation. Research on adhesives is presented in respect to bonding agents for dentin and enamel. Several clinical studies are included, along with customary laboratory reports on several materials.