Position Paper: The Role of Supra- and Subgingival Irrigation in the Treatment of Periodontal Diseases

Mechanical plaque removal in step-1 of care

Maintaining a regular oral hygiene routine is essential for taking care of our mouths, ensuring healthy teeth, and achieving fresh breath. Patient education on oral hygiene is an important component of their overall treatment. Firstly, patients should be informed about the direct connection between bacteria in dental plaque and oral diseases. It is important for patients to understand that these conditions can be treated, but the success of treatment greatly depends on their level of oral hygiene. This journey begins by selecting the appropriate toothbrush and mastering the correct brushing technique to effectively remove dental plaque while avoiding any potential damage to the gums. In addition to toothbrushes, there are other devices available for comprehensive dental cleaning, such as floss, interdental sticks, interdental brushes, and oral irrigators. These aids are particularly beneficial for eliminating dental plaque from hard-to-reach areas. Moreover, tongue brushing or tongue scraping can effectively reduce breath odor and tongue coating. Currently, self-care recommendations for dental implants are primarily based on existing knowledge regarding natural teeth cleaning. Evidence-based recommendations are derived from comprehensive systematic evaluation of various oral hygiene aids.

Effect of a multichannel oral irrigator on periodontal health and the oral microbiome

Oral biofilms or dental plaques are one of the major etiological factors for diverse oral diseases. We aimed to evaluate the effect of a multichannel oral irrigator (MCOI) on periodontal health in 29 participants randomly divided into two groups: the MCOI group and the control group. To evaluate the effect of the MCOI on periodontal health, the modified Quigley Hein Plaque Index (PI), Mühlemann-Son Sulcus Bleeding Index (SBI), bleeding on probing (BOP), and swelling were evaluated and compared before and after MCOI use for 3 days. Although PI and SBI showed statistically significant increases in the control group, the MCOI group showed no significant changes in either parameter. Moreover, the percentage of BOP was significantly lower in the MCOI group. Saliva samples were analyzed by 16s rRNA amplicon sequencing to investigate changes in the oral microbiome. Sequencing results showed that Porphyromonas spp. were significantly increased in the control group, whereas no significant change was detected in the MCOI group. Using the MCOI, enriched populations and functional pathways were detected in pioneer species comprising non-mutans streptococci. These findings provide evidence of the effectiveness of the MCOI in maintaining periodontal health and a healthy microbial ecology in the oral cavity.

The Efficacy and Safety of Oral Irrigator on the Control of Dental Plaque and Gingivitis: A Randomized, Single-Blind, Parallel-Group Clinical Trial

BACKGROUND

To evaluate the efficacy and safety of oral irrigator (OI) in controlling dental plaque and gingivitis.

METHODS

Ninety participants diagnosed with gingivitis were randomly assigned to two groups, given a toothbrush combined with OI (WaterPik®) (test) or a toothbrush alone (control). The Turesky-Modified Quigley-Hein Plaque Index (T-QH), Modified Gingival Index (MGI), Bleeding Index (BI), and percentage of sites with bleeding on probing (BOP%) were evaluated at baseline, 4 weeks, 8 weeks, and 12 weeks. The full analysis set (FAS) and per-protocol set (PPS) were analyzed. Adverse events were recorded through electronic diaries and examinations.

RESULTS

Of the 90 participants, the efficacy was assessed in the following numbers (FAS/PPS): test (45/33) and control (43/38). Compared with the control, MGI, BI, and BOP% were significantly lower in the test group after 4 weeks (4 weeks: p = 0.017, p = 0.001, and p = 0.001, respectively; 8 weeks and 12 weeks: p < 0.001 for all, FAS); T-QH was significantly lower after 8 weeks (8 weeks: p = 0.033; 12 weeks: p = 0.006, FAS). Transient gingival bleeding may be associated with OI. Self-reported pain and dentin hypersensitivity symptoms were similar between groups.

CONCLUSIONS

As adjuncts to toothbrushing, OI demonstrated significantly better efficacy in controlling dental plaque and gingival inflammation with no substantial safety hazards.

Local Oral Delivery Agents with Anti-Biofilm Properties for the Treatment of Periodontitis and Peri-Implantitis. A Narrative Review

Despite many discoveries over the past 20 years regarding the etiopathogenesis of periodontal and peri-implant diseases, as well as significant advances in our understanding of microbial biofilms, the incidence of these pathologies continues to rise. For this reason, it was clear that other strategies were needed to eliminate biofilms. In this review, the literature database was searched for studies on locally delivered synthetic agents that exhibit anti-biofilm properties and their potential use in the treatment of two important oral diseases: periodontitis and peri-implantitis.

Antibiofilm effect of ozonized physiological saline solution on peri-implant-related biofilm

BACKGROUND

Removal of dental plaque and local application of local chemical adjuncts, such as chlorhexidine (CHX), have been used to control and treat peri-implant disease. However, these methods can damage the surface properties of the implants or promote bacterial resistance. The application of ozone as an adjunctive treatment represents a new approach in the management of peri-implantitis. Thus, the purpose of this study was to evaluate the antimicrobial effect of ozonized physiological saline solution in different concentrations against oral biofilms developed on titanium surface.

METHODS

Single and multi-species biofilms of Porphyromonas gingivalis, Fusobacterium nucleatum, and Streptococcus oralis were formed on titanium specimens for 5 days in anaerobic conditions. Biofilms were treated with ozonized saline solution at different concentrations (25, 50, and 80 μg/NmL), for 30 seconds and 1 minute. CHX (0.12%) and saline solution (0.89% NaCl) were used as positive and negative controls, respectively. Bacterial viability was quantified by colony forming units (CFU mL^-1 ), and biofilm images were acquired by confocal laser scanning microscopy (CLSM). Data were analyzed by parametric test (ANOVA) with Tukey post-hoc test (P < 0.05).

RESULTS

Ozonized saline solution showed antibiofilm activity at a concentration of 80 μg/NmL for 30 seconds and 1 minute, reducing, mainly, Porphyromonas gingivalis viability, with 2.78 and 1.7 log₁₀ CFU mL^-1 of reduction in both single and multi-species biofilms, respectively, when compared to the control (saline), whereas CHX reduced 1.4 and 1.2 log₁₀ CFU mL^-1 .

CONCLUSION

Ozonized saline solution has antibiofilm activity, with better effect when applied for 1 minute at 80 μg/NmL, being a promising candidate therapy for the treatment of peri-implant diseases.

Evaluation of the efficacy of subgingival irrigation in patients with moderate-to-severe chronic periodontitis otherwise indicated for periodontal flap surgeries

Background:

In certain medically and physically compromised; and terminally ill patients, periodontal surgery may not be feasible. They need special attention and assistance for their daily plaque control regimens for the management and maintenance of periodontal conditions. Subgingival irrigation home care devices with antiplaque agents may serve as useful tools in such specific patient populations.

Aims:

The aim of this study was to evaluate of the efficacy of sub-gingival irrigation in patients with moderate-to-severe chronic periodontitis otherwise indicated for periodontal flap surgeries.

Settings and Design:

Randomized comparative parallel group interventional clinical trial.

Materials and Methods:

Forty adults with moderate-to-severe periodontitis, divided inot Group A and B, were subjected to the use of subgingival home irrigations using 0.06% chlorhexidine (CHX) and mouth-rinsing with 15 ml of 0.12% CHX twice daily, respectively after Phase I therapy. Clinical parameters, i.e., gingival index, oral hygiene index simplified, and bleeding on probing scores were assessed at baseline, 2 weeks, 4 weeks, and 12 weeks’ postphase I therapy, whereas clinical attachment level (CAL), probing depth (PD), and stain assessment at baseline and 12 weeks following Phase I therapy.

Statistical Analysis Used:

Statistical Package for Social Sciences (SPSS Inc., Chicago, IL, USA version 15.0 for Windows).

Results:

A statistically significant difference was seen with the use of 0.06% CHX irrigations in PD (P = 0.004) and CAL (P = 0.002) as compared to the use of mouth rinsing with 0.12% CHX. Similar differences were observed in both intensity (P = 0.014) and area (P = 0.034) of lingual surface staining with greater staining with CHX mouth rinsing.

Conclusion:

The adjunctive use of subgingival home irrigations using 0.06% CHX has a promising potential to maintain the oral health and results in lesser staining compared to CHX mouth rinsing. The regimen may further obviate the need of periodontal surgery in medically compromised subjects.

Clinical and Microbiological Effects of Weekly Supragingival Irrigation with Aerosolized 0.5% Hydrogen Peroxide and Formation of Cavitation Bubbles in Gingival Tissues after This Irrigation: A Six-Month Randomized Clinical Trial

Introduction

The study investigated the effect of weekly supragingival irrigation with aerosolized 0.5% hydrogen peroxide (H₂O₂) solution as a maintenance periodontal therapy on clinical and microbiological parameters in patients with chronic periodontitis. The other purpose was to investigate whether cavitation bubbles can penetrate not only into periodontitis-damaged tissues but also into ex vivo porcine healthy periodontal tissues.

Materials and Methods

The study included 35 systemically healthy patients with chronic periodontitis (CP). After nonsurgical periodontal debridement (NSPD), all patients were randomized into two groups: the Control group (NSDP alone, n = 18) and the Test group (NSDP plus supragingival irrigation, n = 17). Clinical (Approximal Plaque Index (API), Bleeding Index (BI), and Modified Gingival Index (MGI)) and microbiological (Polymerase Chain Reaction technology (using a micro-IDent® kit)) measurements were performed at the initial time point, 3 months, and 6 months after NSPD. The impact of supragingival irrigation on diseased gingival tissues of CP patients (n = 5) and on ex vivo porcine healthy gingival tissue samples (n = 3) was evaluated to estimate morphological changes in healthy and diseased gingival tissues.

Results

Morphological data revealed that supragingival irrigation caused the formation of cavitation bubbles in diseased gingival tissue of CP patients and in healthy porcine gingival tissues. The decrease in API, BI, and MGI scores after 6 months in the Test group significantly (p ≤ 0.01, p ≤ 0.05, and p ≤ 0.01, respectively) exceeded that in the Control group. Test group patients demonstrated a decrease in periodontal sites showing Pocket Probing Depth > 4 mm and, after 6 months, a statistically significant decrease in the proportion of periopathogenic bacteria.

Conclusion

The effectiveness of mechanical periodontal treatment combined with weekly supragingival irrigation with aerosolized 0.5% H₂O₂ solution on clinical and microbiological parameters of periodontal tissues of periodontitis patients is reliably higher than that of mechanical periodontal debridement alone. It has been found that cavitation bubbles as a result of irrigation with the aerosolized 0.5% hydrogen peroxide solution can form not only in periodontal tissues of periodontitis patients but also in ex vivo porcine healthy gingival tissues.

Effect of sodium ascorbyl phosphate on osteoblast viability and differentiation

OBJECTIVES AND BACKGROUND

Sodium ascorbyl phosphate (SAP) is a hydrophilic and stable L-ascorbic acid derivative, being converted by the cell phosphatases into free ascorbic acid (AA), which allows its sustained release in the medium. AA participates in the maintenance and healing of the periodontium. It presents a regulatory role of the osteoblastic activity, stimulating the deposition of collagen extracellular matrix followed by the induction of genes associated with the osteoblastic phenotype. It also acts in the elimination of reactive oxygen species, abundantly produced by defense cells in periodontal disease. The aim of this study was to evaluate the effect of SAP on osteoblast viability and differentiation.

METHODS

Mouse preosteoblastic cells of the MC3T3-E1 strain were used. Cell viability was assessed by the trypan blue dye exclusion assay and the expression of genes related to osteoblast differentiation by quantitative PCR. Collagen I secretion was evaluated by ELISA, and mineralized matrix formation was assayed by Alizarin red S staining.

RESULTS

The results showed that SAP at concentrations from 50 to 500 µmol/L does not influence preosteoblast cell viability, but stimulates their differentiation, observed by the induction of RUNX2, COL1A1, and BGLAP2; by the higher secreted levels of collagen I; and also by the increase in the mineralization of the extracellular matrix in cells exposed to this agent at 200 or 400 µmol/L, compared with those not exposed.

CONCLUSION

By its stability and capacity to induce preosteoblastic cell differentiation, our results indicate that the incorporation of SAP into local release devices, membranes/scaffolds or biomaterials, could favor bone tissue formation and therefore periodontal healing.

Treatment of Peri-Implant Mucositis with Repeated Application of Chlorhexidine Chips or Gel during Supportive Therapy - A Randomized Clinical Trial

Running head

Peri-implant maintenance with CHX

Abstract

Background: To assess the effect of chlorhexidine (CHX) chip application in patients with peri-implant mucositis as compared to CHX gel application. Methods: In peri-implant sites with mucositis, CHX gel was applied in the control group (GC) and CHX chips in the test group (CC) at baseline and after three months. At baseline and after six months, peri-implant pocket depths (PPD), bleeding-on-probing (BOP) and activated matrix metalloproteinase-8 (aMMP8) were assessed. Longitudinal changes were tested for inter-group differences. Results: Thirty-two patients were treated. BOP was more reduced (p = 0.006) in CC than in GC, with means and standard deviations of 46 ± 28% and 17 ± 27%, respectively. PPD was more reduced (p = 0.002) in CC than in GC with 0.65 ± 0.40 mm and 0.18 ± 0.32 mm, respectively. Regarding BOP, the percentages of improved, unchanged and worsened sites accounted for 32%, 61% and 7% in GC and 46%, 53% and 1% in CC, respectively. For probing pocket depth, the according values were 26%, 66% and 8% (GC) versus 57%, 38% and 5% (CC). Conclusions: During supportive therapy, repeated CHX chip application might resolve marginal peri-implant inflammation in terms of bleeding better than CHX gel.

Clinical and patient-centered outcomes post non-surgical periodontal therapy with the use of a non-injectable anesthetic product: A randomized clinical study

Aim

The aim of this study was to determine the impact of different full‐mouth decontamination (FMD) protocols on the effectiveness of an intrapocket anesthetic gel in periodontal maintenance patients.

Methods

Patients undergoing the periodontal maintenance program and with the need for FMD participated in this study. Patients were randomly allocated to non‐surgical periodontal therapy (NSPT) with either a preparatory 15‐day decontamination phase, including chlorhexidine mouth rinse and domiciliary hygiene instructions (modified FMD: test group), or without it (FMD: control group). In both groups, NSPT was performed with the aid of a non‐injectable anesthetic gel. Clinical and patient‐related outcomes were recorded during a 6‐month follow‐up period.

Results

Sixty patients completed the 6‐month study. Both groups experienced relevant clinical improvements after NSPT, but the test group showed a significant change in periodontal parameters already after the initial 15‐day preparatory period, and overall significantly better results in periodontal outcomes when compared with the control group at the last 6‐month follow up: the gingival index was 2.07 ± 1.25 in the control group and 1.13 ± 0.51 in the test group. Less pain and dental‐related anxiety were perceived by patients in the test group showing a 6‐month mean visual analog scale of 2.13 ± 1.25 in the control group and 1.13 ± 0.83 in the test group.

Conclusion

The present study suggested that the modification of the standard FMD could improve the clinical efficacy of non‐injectable anesthetic, along with patients’ short‐ and mid‐term appreciation and compliance.

An Overview of Different Interdental Cleaning Aids and Their Effectiveness

Optimisation of plaque control is essential for the success of non-surgical and surgical periodontal therapy. This cannot be achieved with brushing alone; hence, there is a need for adjunctive interdental cleaning aids. The aim of this paper is to provide an overview of different interdental cleaning aids and review the literature for consensus on their effectiveness. A literature search of articles in English, up to December 2018, was conducted in Pubmed. High-quality flossing is difficult to achieve, and ineffective routine use of floss may not confer significant benefits over brushing alone. Interdental brushes are more effective than brushing as a monotherapy. They are at least as good if not superior to floss in reducing plaque and gingivitis. Although they are effective for patients regardless of their periodontal status (healthy or active), they are especially indicated in periodontal patients where widened embrasures are common. Added benefits include ease of use, patient acceptance, and recontouring of interdental tissues. Rubberpiks do not demonstrate inferiority to conventional interdental brushes. Wooden interdental aids appear to offer no significant advantage over brushing with respect to plaque removal; they may, however, reduce gingival bleeding. Oral irrigators are a promising tool for reducing gingival inflammation, despite minimal changes to plaque levels. For cleaning around dental implants, oral irrigators and interdental brushes are preferred over floss.

Comparative evaluation of the chlorhexidine and cinnamon extract as ultrasonic coolant for reduction of bacterial load in dental aerosols

Background:

Ultrasonic instruments generate aerosols with significantly greater number of bacteria. Preprocedural mouthrinses or chemotherapeutic coolants are used for the reduction of bacterial load in dental aerosols. The use of chlorhexidine as an ultrasonic coolant has been well established. However, this application has not yet been investigated for cinnamon extract which is known to have antibacterial and anti-inflammatory properties in vivo.

Aim:

The aim of this study is to compare and evaluate the efficacy of chlorhexidine and cinnamon extract as an ultrasonic coolant in reduction of aerosol contamination and biofilm formation during ultrasonic scaling in comparison with the distilled water (DW).

Materials and Methods:

Sixty patients diagnosed with moderate-to-severe gingivitis were randomly divided into three groups of twenty patients each undergoing ultrasonic scaling. For Group I, chlorhexidine was used as an ultrasonic coolant; for Group II, cinnamon extract was used; and Group III was served as control where DW was used. The aerosols from ultrasonic units were collected on two blood agar plates at three different positions. Both the plates from each position were incubated aerobically for 48 h. The total number of colony-forming units were counted as mean ± standard deviation and statistically analyzed. In addition, biofilm sampling of dental unit waterlines (DUWLs) was also done to evaluate the effect of these antimicrobials. Apart from microbial examination, clinical parameters such as plaque index and gingival index were also evaluated at baseline and 1-month follow-up.

Results:

Chlorhexidine and cinnamon both were equally effective (P > 0.05) in reducing the bacterial count in aerosols and biofilm in DUWL as compared to DW when used as ultrasonic cooling agent.

Conclusion:

Both cinnamon and chlorhexidine used as an ultrasonic device coolant through DUWLs effectively helped in the reduction of bacterial count in dental aerosols.

Oral Microbes, Biofilms and Their Role in Periodontal and Peri-Implant Diseases

Despite many discoveries over the past 20 years regarding the etio-pathogenesis of periodontal and peri-implant diseases, as well as significant advances in our understanding of microbial biofilms, the incidence of these pathologies still continues to rise. This review presents a general overview of the main protagonists and phenomena involved in oral health and disease. A special emphasis on the role of certain keystone pathogens in periodontitis and peri-implantitis is underlined. Their capacity to bring a dysregulation of the homeostasis with their host and the microbial biofilm lifestyle are also discussed. Finally, the current treatment principles of periodontitis and peri-implantitis are presented and their limits exposed. This leads to realize that new strategies must be developed and studied to overcome the shortcomings of existing approaches.

Adult periodontitis treated with a new device for subgingival lavage-a randomized controlled clinical trial using a split-mouth design

OBJECTIVES

To evaluate in patients with untreated adult periodontitis, the effect of treatment with a novel pocket irrigator/evacuator device (IED) compared to conventional subgingival debridement (CPT), both provided during the initial phase of active periodontal therapy.

METHODS

This study was an examiner-blind, randomized controlled clinical trial using a split-mouth design. Systemically healthy patients with adult periodontitis were selected. Full-mouth probing pocket depth (PPD), gingival bleeding on pocket probing scores (BOPP), gingival recession (REC) and dental plaque (PI) were assessed at baseline. All participants received oral hygiene instructions and supragingival prophylaxis including polishing. In 2 randomly assigned contra-lateral quadrants, approximal sites were irrigated with the IED, whereas in the other quadrants, CPT was provided. The CPT consisted of subgingival debridement using ultrasonic devices followed by the use of hand instruments. At 3 months post-treatment, the clinical parameters were re-assessed.

RESULTS

Twenty-five patients met the inclusion criteria and were willing to participate. At 3 months post-treatment, the PPD and BOPP had significantly improved for both treatment modalities. Pockets of ≥5 mm reduced by 0.64 mm in the IED group (P < .001), compared to a reduction of 0.82 mm for the CPT group (P < .001). With respect to the primary outcome parameter (PPD) and BI, the results with the IED were less pronounced. Between the test and control groups, no significant differences were observed for REC and PI.

CONCLUSIONS

Oral hygiene instructions, supragingival prophylaxis and subgingival lavage with the IED resulted in a significant reduction in PPD and BOPP. However, the effect does not reach the results of CPT which included the subgingival use of ultrasonic and hand instruments.

Effect of Supragingival Irrigation with Aerosolized 0.5% Hydrogen Peroxide on Clinical Periodontal Parameters, Markers of Systemic Inflammation, and Morphology of Gingival Tissues in Patients with Periodontitis

BACKGROUND Various studies have shown that non-surgical periodontal treatment is correlated with reduction in clinical parameters and plasma levels of inflammatory markers. The aim of this study was to evaluate the effect of long-term weekly supragingival irrigations with aerosolized 0.5% hydrogen peroxide as maintenance therapy followed by non-surgical periodontal treatment on clinical parameters, plasma levels of inflammatory markers, and morphological changes in gingival tissues of patients with periodontitis. MATERIAL AND METHODS In total, 43 patients with chronic periodontitis were randomly allocated to long-term maintenance therapy. The patients' periodontal status was assessed using clinical parameters of approximal plaque index, modified gingival index, bleeding index, pocket probing depth, and plasma levels of inflammatory markers (high-sensitivity C-reactive protein and white blood cell count) at baseline and after 1, 2, and 3 years. The morphological status of gingival tissues (immediately after supragingival irrigation) was assessed microscopically. RESULTS Complete data were obtained on 34 patients. A highly statistically significant and consistent reduction was observed in all long-term clinical parameters and plasma levels of inflammatory markers. Morphological data showed abundant spherical bubbles in gingival tissues. CONCLUSIONS 1. The present study showed that non-surgical periodontal treatment with long-term weekly supragingival irrigations with aerosolized 0.5% hydrogen peroxide improved clinical periodontal status and plasma levels of inflammatory markers and may be a promising method in periodontology. 2. We found that supragingival irrigation with aerosolized 0.5% hydrogen peroxide created large numbers of spherical bubbles in gingival tissues.

Adjunctive use of essential oils following scaling and root planing -a randomized clinical trial

BACKGROUND

Hitherto no study has been published on the effect of the adjunctive administration of essential oils following scaling and root planing (SRP). This study describes the effect of a mouthrinse consisting of essential oils (Cymbopogon flexuosus, Thymus zygis and Rosmarinus officinalis) following SRP by clinical and microbiological variables in patients with generalized moderate chronic periodontitis.

METHODS

Forty-six patients (aged 40-65 years) with moderate chronic periodontitis were randomized in a double-blind study and rinsed their oral cavity following SRP with an essential oil mouthrinse (n  =  23) or placebo (n  =  23) for 14 days. Probing depth (PD), attachment level (AL), bleeding on probing (BOP) and modified sulcus bleeding index (SBI) were recorded at baseline and after 3 and 6 months. Subgingival plaque was taken for assessment of major bacteria associated with periodontitis.

RESULTS

AL, PD, BOP and SBI were significantly improved in both groups after three (p   <   0.001) and 6 months (p   ≤   0.015). AL improved significantly better in the test than in the control group after 3 and 6 months (p < 0.001), so did PD after three months in the tendency (p  =  0.1). BOP improved better in the test group after 3 months (p  =  0.065). Numbers of Treponema denticola (p  =  0.044) and Fusobacterium nucleatum (p  =  0.029) decreased more in the test than in the control group after 3 months, those of Tannerella forsythia after 6 months (p  =  0.039). Prevotella micra (p  <  0.001, p  =  0.035) and Campylobacter rectus (p  =  0.002 , p  =  0.012) decreased significantly in both groups after 3 months.

CONCLUSIONS

The adjunctive use of a mouthrinse containing essential oils following SRP has a positive effect on clinical variables and on bacterial levels in the subgingival biofilm.

TRIAL REGISTRATION

332-12-24092012, DRKS 00009387, German Clinical Trials Register, Freiburg i. Br., 16.09.2015.

Cytotoxicity and genotoxicity of chlorhexidine on macrophages in vitro

Chlorhexidine (CHX) is the most widely used antiseptic for wound, skin disinfection, and dental hygiene. The aim of this study is to investigate the possible correlation between CHX-induced cytogenotoxicity and alterations in normal cell cycle on RAW264.7 macrophages. The cytotoxicity, mechanism of cell death, mitotic activity, and reactive oxygen species (ROS) generation were determined by tetrazolium bromide reduction assay, flow cytometry, cytokinesis-block proliferation index, and superoxide dismutase-inhibitable reduction of ferricytochrome c, respectively. The genotoxicity was measured using comet assay and cytokinesis-block micronucleus assay. The cytotoxicity of CHX in RAW264.7 cells presented a dose- and time-dependent manner (p < 0.05). The mode of cell death shifted from apoptosis to necrosis when the dosage of CHX increased. The genotoxicity of CHX in RAW264.7 cells had shown DNA damage in a dose-dependent manner (p < 0.05). Prolongation of cell cycle and the increase of ROS generation also expressed in a dose-dependent manner (p < 0.05). Taken together, the data suggested that CHX-induced cytotoxicity and genotoxicity on macrophages may be via ROS generation.

Clearance of topically-applied PVP-iodine as a solution or gel in periodontal pockets in men

OBJECTIVES

The aim of the study was to investigate the clearance of PVP-iodine applied as a gel or solution in periodontal pockets.

METHODS

Teeth of 12 subjects with at least eight periodontal pockets of ≥5 mm probing depth were isolated with a rubber dam to allow contamination-free access to the pockets. In each subject, three pockets were filled with PVP-iodine gel (10%) and three with PVP-iodine solution (10%). One pocket of each subject without iodine application served as a negative control. The treatment allocation was assigned randomly. Any excess material was removed subsequently. After 1, 5 and 15 min, a paper point was used to collect the sulcus liquid and the concentration of PVP-iodine was chemically determined. In addition, PVP-iodine gel was administered into 12 periodontal pockets immediately after sub-gingival ultrasound debridement and the concentration of PVP-iodine was determined after 1 min.

RESULTS

Descending concentrations of PVP-iodine were determined at 1, 5 and 15 min after the application. No PVP-iodine was found in the pockets serving as negative controls. The mean concentrations of the gel and solution were 6.14 μg/ml and 4.44 μg/ml (1 min; p ≥ 0.028), 3.20 μg/ml and 1.44 μg/ml (5 min; p ≥ 0.126), 0.69 μg/ml and 0.23 μg/ml (15 min; p ≤ 0.019), respectively. In the pockets with previous debridement the mean concentration was 1.68 ± 1.97 μg/ml.

CONCLUSION

The application of PVP-iodine gel in periodontal pockets allows a prolonged remnant effect as compared to that of the solution formula.

Treatment modalities and evaluation models for periodontitis

Periodontitis is the most common localized dental inflammatory disease related with several pathological conditions like inflammation of gums (gingivitis), degeneration of periodontal ligament, dental cementum and alveolar bone loss. In this perspective, the various preventive and treatment modalities, including oral hygiene, gingival irrigations, mechanical instrumentation, full mouth disinfection, host modulation and antimicrobial therapy, which are used either as adjunctive treatments or as stand-alone therapies in the non-surgical management of periodontal infections, have been discussed. Intra-pocket, sustained release systems have emerged as a novel paradigm for the future research. In this article, special consideration is given to different locally delivered anti-microbial and anti inflammatory medications which are either commercially available or are currently under consideration for Food and Drug Administration (FDA) approval. The various in vitro dissolution models and microbiological strain investigated to impersonate the infected and inflamed periodontal cavity and to predict the in vivo performance of treatment modalities have also been thrashed out. Animal models that have been employed to explore the pathology at the different stages of periodontitis and to evaluate its treatment modalities are enlightened in this proposed review.

Systematic review on the effect of rinsing with povidone-iodine during nonsurgical periodontal therapy

BACKGROUND AND OBJECTIVE

The existing literature is inconsistent regarding whether there is any additional effect of povidone-iodine (PVP-iodine) as an adjunctive to scaling and root planing, and, if there is an effect, what its size is. Therefore, the aim of this study was to assess the additional effect of PVP-iodine as an adjunct to scaling and root planing compared with water, saline or no rinse in the treatment of chronic periodontitis.

MATERIAL AND METHODS

An electronic literature search of the databases PubMed, EMBASE and the Cochrane Central Library, and a handsearch, were performed (up to November 2008). Two reviewers independently identified and selected screened abstracts for possible inclusion, and assessed randomized, controlled clinical trials comparing the additional benefit of PVP-iodine with water, saline rinsing or no rinsing in the nonsurgical periodontal therapy of patients with chronic periodontitis. A fixed-effects meta-analysis was conducted in the absence of statistically significant heterogeneity.

RESULTS

A small, but statistically significant additional beneficial effect of the adjunctive use of PVP-iodine with enhanced probing pocket depth reductions of 0.28 mm (95% confidence interval: 0.08 to 0.48, p = 0.007) was found. There was no significant heterogeneity between studies (I(2) = 0%). However, most of the studies included in the meta-analysis were of low quality, and the treatment modalities showed various differences such as the use of PVP-iodine at different concentrations and application modalities. Nevertheless, single-rooted teeth, in particular, showed an additional benefit after scaling and root planing with PVP-iodine, particularly when the treatment was repeated during the healing stage.

CONCLUSION

The adjunctive use of PVP-iodine during scaling and root planing may increase the clinical pocket depth reduction, although the clinical significance is small to moderate.

Effect of short-time povidone-iodine application on osteoblast proliferation and differentiation

Background and Objective:

Povidone-iodine [polyvinylpyrrolidone-iodine complex (PVP-I)] is a broad-spectrum antimicrobial agent, frequently used in dentistry. In this study we investigated the short- and longterm effects on osteoblast number, viability, and function after short exposure to PVP-I with and without additional bone-morphogenetic protein-2 (BMP-2).

Material and Methods:

Confluent osteoblast-like cell line (MC3T3-E1, subclone 24) cultures were exposed to pure PVP-I solution (7.7 mg/ml) and dilutions of 1:10, 1:100 and 1:1000 for 10 seconds and washed with phosphate buffer solution. Cell proliferation and viability was determined by MTT and differentiation status by alkaline phosphatase (ALP) activity 6 days after initial plating. In a separate experiment, long-term cell proliferation, viability and function were assessed 4 weeks after PVP-I treatment by MTT and deposited calcium using an Alizarin-red staining test.

Results:

PVP-I decreased ALP activity substantially. Stimulation by BMP-2 recovered ALP activity to near control levels at 1:100 and 1:1000 dilutions of PVP-I. The MTT assay showed reduced proliferation of the preosteoblastic cells for all treatments, irrespective whether BMP-2 was used or not. Only at PVP-I dilutions of 1:1000 proliferation rate was back to normal levels (95.6±2.4 %). No adverse long-term effect of PVP-I on mineralization of the extracellular matrix (Alizarinred) for dilutions higher than 1:100 was observed. Interestingly, undiluted and 1:10 diluted PVP-I even showed a significant increase in mineral deposition, especially in the presence of BMP-2.

Conclusion:

Short-time application of PVP-I in concentrations of 1:10 and higher lead to decreased viability and impaired differentiation. However, surviving cells showed good recovery and mineralization potential.

Photodynamic therapy of persistent pockets in maintenance patients-a clinical study

The aim of this study was to compare the short-term performance of a session of single photodynamic therapy (PDT) and of a conventional ultrasonic debridement (UST) in persistent pockets of maintenance patients. In a prospective, randomized, controlled, single-blind clinical study, patients with chronic periodontitis with at least two persistent pockets (>4 mm) were enrolled. They were treated either with UST (n = 29) or PDT (n = 25). Clinical and microbiological examinations were performed at baseline and after 3 months. For UST, the mean probing depth was reduced from 5.3 to 4.5 mm (p = <0.001) and for PDT from 5.3 to 4.7 mm (p < 0.001) with no difference between the two treatment modalities. Microbial counts were significantly reduced about 30% to 40% immediately after debridement but returned to baseline values a 3 months irrespective of treatment. PDT is not superior to conventional mechanical treatment of persistent pockets, but it may be a meaningful therapeutic alternative; the clinical effects were too minor to draw a definitive conclusion.

Periodontal Debridement With Povidone-Iodine in Periodontal Treatment: Short-Term Clinical and Biochemical Observations

BACKGROUND

The aim of the present study was to evaluate the clinical effects of one-stage periodontal debridement with an ultrasonic instrument, associated with 0.5% povidone (pvp)-iodine irrigation in patients with chronic periodontitis.

METHODS

Forty-five patients were randomly assigned into three groups: the control group (CG) received quadrant root planing at 1-week intervals over four consecutive sessions; the periodontal debridement plus pvp-iodine group (PD-PIG) received a 45-minute full-mouth debridement with an ultrasonic instrument, associated with 0.5% pvp-iodine irrigation; and the periodontal debridement group (PDG) received a 45-minute full-mouth periodontal debridement with an ultrasonic instrument, associated with NaCl irrigation.

RESULTS

At the 3-month evaluation, the mean probing depth (PD) reduction in CG was 2.51+/-0.52 mm, 2.53+/-0.50 mm in PD-PIG, and 2.58+/-0.60 mm in PDG (P<0.05). The clinical attachment level (CAL) analysis showed a statistically significant gain in all groups compared to baseline (1.87+/-0.56 mm [CG], 1.94+/-0.70 mm [PD-PIG], and 1.99+/-0.92 mm [PDG]). Intergroup analysis of PD and CAL at 1 and 3 months showed no differences (P>0.05). The N-benzoyl-L-arginine-p-nitroanilide (BAPNA) test showed a significant reduction in trypsin activity only during the first month (P<0.05); at 3 months there were no differences compared to baseline (P=0.80).

CONCLUSION

This study provides no evidence that pvp-iodine is effective as an adjunct for one-stage periodontal debridement.