Mouthwashes for the control of supragingival biofilm and gingivitis in orthodontic patients: evidence-based recommendations for clinicians

Biomarkers of Orthodontic Patients After Use of 1% Brazilian Red Propolis Toothpaste: A Randomized Clinical Study

Aim

To evaluate the salivary biomarkers and plaque index after a treatment with a propolis-contained toothpaste.

Materials and Methods

This is a longitudinal, randomized, double-blind study where 76 participants were randomized into two groups: Group I: Fluoridated Red Propolis toothpaste; Group II: Fluoridated toothpaste. The participants were selected in a municipality without fluoridated public water. All participants received standardized oral hygiene instructions from the same instructor for 3 daily brushings (after breakfast, after lunch, and before bed) for a period of 2 min; Saliva samples were collected before (D0) and after 28 days (D28) of treatment for analysis of pH and total protein, amylase, and IL-10. Saliva was collected in the initial consultation and on return, totaling two collections. All samples were collected under the same conditions, by the same operator and between 9:00 AM and 11:00 AM in order to minimize the influence of circadian rhythm on salivary flow.

Results

On D0 and D28, the various treatments had no effect on total salivary proteins (G1: P = 0.0746; G2: P = 0.2144), and the pH stayed about the same. Additionally, there was no change in the amylase activity in G1 (P = 0.1877) or G2 (P = 0.4674). Significant decreases in G1 (P < 0.0001) and G2 (P = 0.03) were observed with IL-10. There was no statistically significant difference in the salivary flow between the BRP toothpaste-treated group (P = 0.172) and the commercial fluoridated toothpaste-treated group (P = 0.329). Compared to G2 (P = 0.03), G1 showed a superior decline in the plaque index (P = <0.0001).

Conclusions

After 28 days of using the toothpastes, there were no changes in the amylase, pH, or total protein indicators. After 28 days, there was a decrease in the propolis group's IL-10 dose and plaque index.

Osteocyte Mechanotransduction in Orthodontic Tooth Movement

PURPOSE OF REVIEW

Orthodontic tooth movement is characterized by periodontal tissue responses to mechanical loading, leading to clinically relevant functional adaptation of jaw bone. Since osteocytes are significant in mechanotransduction and orchestrate osteoclast and osteoblast activity, they likely play a central role in orthodontic tooth movement. In this review, we attempt to shed light on the impact and role of osteocyte mechanotransduction during orthodontic tooth movement.

RECENT FINDINGS

Mechanically loaded osteocytes produce signaling molecules, e.g., bone morphogenetic proteins, Wnts, prostaglandins, osteopontin, nitric oxide, sclerostin, and RANKL, which modulate the recruitment, differentiation, and activity of osteoblasts and osteoclasts. The major signaling pathways activated by mechanical loading in osteocytes are the wingless-related integration site (Wnt)/β-catenin and RANKL pathways, which are key regulators of bone metabolism. Moreover, osteocytes are capable of orchestrating bone adaptation during orthodontic tooth movement. A better understanding of the role of osteocyte mechanotransduction is crucial to advance orthodontic treatment. The optimal force level on the periodontal tissues for orthodontic tooth movement producing an adequate biological response, is debated. This review emphasizes that both mechanoresponses and inflammation are essential for achieving tooth movement clinically. To fully comprehend the role of osteocyte mechanotransduction in orthodontic tooth movement, more knowledge is needed of the biological pathways involved. This will contribute to optimization of orthodontic treatment and enhance patient outcomes.

EO-based mouthwashes: Is there something that should be known?

The possibility to utilize the antibacterial and antibiofilm potential of essential oils (EOs) in dentistry is recognized and best seen in the design of EO-based mouthwashes. The up-to-date results, obtained with the most commonly used formulation being consisted of thymol, eucalyptol, menthol, and methyl salicylate (Listerine), proved its efficacy against plaque and gingival inflammation. However, novel alcohol-free products remain to be further investigated. Commercially available mouthwash containing curcumin, clove oil, mentha oil, eucalyptol, thymol and tea tree oil, and the mouthwash based on ginger EO (a-zingiberene, b-bisabolene, b-sesquiphellandrene, curcumene), reduced plaque index and improved periodontal status of the patients. The plaque index was also reduced and overall healing was improved after the surgical removal of the third molar by mouthwash containing John wort oil. In addition, Cinnamomum zeylanicum EO-based mouthwash and mouthwash containing peppermint oil were efficient against stomatitis and xerostomia, respectively. In addition to beneficial effects achieved in the mouth, i.e. at the appropriate site of application, novel investigations pointed-out that EO-based mouthwashes could be recognized as efficient in the reduction of bacterial and viral aerosols. This has been shown for Listerine, and for several mouthwashes containing following active substances of plants' EO origin: a-farnesene, b-farnesene, farnesol, nerolidol, a-bulnesene, eremanthin, b-sesquiphellandrene, spiroether, cinnamylacetate, cinnamaldehyde, eugenol, menthol, and carvacrol. This finding could be of special interest, in order to be included in further clinical studies related to COVID -19 pandemic.

Identification of docosahexaenoic and eicosapentaenoic acids multiple targets facing periodontopathogens

The eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) play a substantial role in Periodontal Disease (PD) due to their antimicrobial and immunomodulatory actions. However, their antimicrobial mechanism of action against bacteria involved in PD remains unclear. We aimed to estimate the probable targets of EPA and DHA against the seven periodontopathogens. Through in silico analyses, the protein-acids interactions, protein characterization, and molecular docking were performed. We identified 165 proteins from periodontopathogens that may interact with EPA and DHA. Fusobacterium nucleatum has the highest number of predicted proteins among analyzed bacteria (n = 43, 26.06%). The EPA shows more interactions than DHA. The EPA and DHA interact mainly with proteins involved in the metabolism (n = 69, 41.81%). Also, the EPA and DHA interact with proteins located in any subcellular location. The affinities between acids and pathogenic proteins were moderate (binding energy was lower than -4.0 kcal/mol). The interactions between EPA and DHA and periodontopathogens occur in multiples proteins. There is not a predilection about the functional class of pathogenic proteins targeting EPA and DHA. However, there are moderate binding affinities between EPA or DHA and essential pathogenic proteins (TolC, CRISPR, FusA).

Gingivitis Effectiveness of Emulgel Containing 2% Resveratrol in Orthodontic Patients: An 8-Week Randomized Clinical Trial

Background

Treatment of gingivitis in patients undergoing orthodontic treatment is done through different methods. Anti-inflammatory agents present in toothpaste or mouthwash are applied spontaneously by patients or used as professional treatment protocols. The present study aimed to investigate the gingivitis effectiveness of Emulgel containing 2% resveratrol in orthodontic patients.

Methods

The study was conducted in three groups, namely, experimental, placebo, and control. In the experimental group, participants used an Emulgel containing 2% resveratrol. In the placebo group, subjects used an identical Emulgel without the active components in the test formulations. After brushing their teeth, the participants learned how to use 5 ml of Emulgel on the gums and massage every night for 30 s. In the control group, subjects were instructed to massage their gums for 30 s every night without any product. Evaluated criteria included bleeding on probing (BOP), gingival index (GI), hyperplastic index (HI), and probing pocket depth (PPD).

Result

During 4 and 8 weeks of the study, the PPD score in the control group did not change significantly but decreased in both groups. Also, there was a decrease in the PPD score in the experimental group compared to the placebo and control groups. Similarly, in the experimental group, continuous use of Emulgel containing 2% resveratrol reduced the HI and GI scores significantly at 4 and 8 weeks after the start of the study. Here, the decrease in GI and HI scores in the experimental group was higher than that of the other groups.

Conclusions

The Emulgel containing 2% resveratrol is effective in improving gingival health in orthodontic patients and can lower gingival inflammation over 8 weeks. This trial is registered with the Iranian registry of clinical trials (https://irct.ir/) IRCT20130812014333N91.

Contribution of Essential Oils to the Fight against Microbial Biofilms—A Review

The increasing clinical use of artificial medical devices raises the issue of microbial contamination, which is a risk factor for the occurrence of biofilm-associated infections. A huge amount of scientific data highlights the promising potential of essential oils (EOs) to be used for the development of novel antibiofilm strategies. We aimed to review the relevant literature indexed in PubMed and Embase and to identify the recent directions in the field of EOs, as a new modality to eradicate microbial biofilms. We paid special attention to studies that explain the mechanisms of the microbicidal and antibiofilm activity of EOs, as well as their synergism with other antimicrobials. The EOs are difficult to test for their antimicrobial activity due to lipophilicity and volatility, so we have presented recent methods that facilitate these tests. There are presented the applications of EOs in chronic wounds and biofilm-mediated infection treatment, in the food industry and as air disinfectants. This analysis concludes that EOs are a source of antimicrobial agents that should not be neglected and that will probably provide new anti-infective therapeutic agents.

Salivary Metalloproteinase-8 and Metalloproteinase-9 Evaluation in Patients Undergoing Fixed Orthodontic Treatment before and after Periodontal Therapy

(1) Background: Metalloproteinase-8 (MMP-8) and metalloproteinase-9 (MMP-9) are members of a family of proteases of major importance during orthodontic tooth movement. Their levels increase during orthodontic therapy and in periodontally affected tissues. Orthodontic fixed appliances retain dental plaque and can cause gingival inflammation. When gingival inflammation is present, the forces produced during orthodontic tooth movement can aggravate tissue reaction and cause the destruction of supportive periodontal tissue. This study aimed to identify biomarkers that facilitate the assessment of periodontal status during orthodontic treatment. (2) Methods: Our study was conducted on 111 patients who were about to receive fixed orthodontic treatment. We determined the salivary levels of MMP-8 and MMP-9 and bleeding on probing (BOP) before applying the orthodontic fixed appliance (T1), one week after appliance placement (T2), and during orthodontic treatment, one month after non-surgical periodontal treatment (T3). (3) Results: Patients undergoing orthodontic treatment show a significant increase in BOP, MMP-8, and MMP-9 levels one week after orthodontic appliance placement (T2) and a decrease in these parameters one month after periodontal treatment (T3). Statistically significant correlations were found between MMP-8 levels and BOP values at T1, T2, and T3. (4) Conclusion: In our study patients undergoing orthodontic treatment show a significant increase in BOP, MMP-8, and MMP-9 levels one week after orthodontic appliance placement and a decrease in these parameters one month after periodontal treatment. Strong positive statistically significant correlations were found between MMP-8 levels and BOP and medium positive statistically significant correlations between MMP-9 and BOP values before and after orthodontic treatment and periodontal treatment. MMP-8, MMP-9, and BOP could be used to assess the periodontal status of orthodontic patients.

Antiplaque and antigingivitis efficacy of cetylpyridinium chloride with zinc lactate compared with essential oil mouthrinses: Randomized clinical trial

BACKGROUND

The authors of this study aimed to evaluate the clinical antiplaque and antigingivitis effects of 3 oral hygiene regimens: toothbrushing with standard fluoride toothpaste and manual toothbrush and using a mouthrinse containing cetylpyridinium chloride, zinc lactate, and fluoride (CPC + Zn + F) in an alcohol-free base; toothbrushing with standard fluoride toothpaste and manual toothbrush and using a mouthrinse containing essential oils (EO) in an alcohol-free base; and toothbrushing with manual toothbrush and standard fluoride toothpaste and manual toothbrush (control).

METHODS

The participants (N = 120) were randomly assigned to study groups and followed the assigned regimens twice daily for 6 weeks. The participants were examined by a calibrated examiner for the Quigley-Hein plaque index (Turesky modification) and Löe-Silness gingival index at baseline, week 4, and week 6. Statistical analyses were performed separately for plaque and gingival indexes by means of analysis of variance, paired t test, and analysis of covariance (α = 0.05).

RESULTS

At week 4, the CPC + Zn + F group presented additional reductions in dental plaque compared with EO and control groups of (21.4% [P < .001] and 31.4% [P < .001], respectively). After 6 weeks, these values were 26.7% (P < .001) and 44.8% (P < .001), respectively. For Löe-Silness gingival index, additional reduction in the CPC + Zn + F group compared with EO were 10.6% (P < .001) and 13.7% (P < .001) at 4 and 6 weeks, respectively. Compared with control, these reductions were 13.6% (P < .001) and 17.8% (P < .001), respectively.

CONCLUSIONS

The regimen including a mouthrinse containing CPC + Zn + F presented higher antiplaque and antigingivitis effects than EO and control regimens.

PRACTICAL IMPLICATIONS

A mouthrinse containing CPC + Zn + F is an effective protocol for the control of dental plaque and gingivitis.

The prevention of periodontal disease-An overview

It is widely accepted that common diseases of the oral cavity, such as gingivitis and periodontitis, are preventable. Based on a large body of scientific evidence, a number of preventive strategies are known to prevent these diseases, but only if routinely implemented. Unfortunately, while most preventive strategies are theoretically simple to understand, they are often difficult to employ in practice at individual and public health levels. This volume of Periodontology 2000 provides the most current information on the state of the science and the evidence base supporting a preventive perspective for the management of periodontal disease, including evidence for proven interventions as well as cutting-edge ideas for potential future interventions. In addition to well-established and scientifically proven approaches (tooth and implant cleansing, topical chemotherapeutics, reduction in risk factors such as tobacco smoking), a number of new ideas are now under investigation, including antioxidant agents, probiotics, vaccines, and slow-release alternative chemotherapeutics. Furthermore, there are new ideas to alter patient behaviors with the aim to improve adherence to preventive strategies. Finally, examples from implementation science and public health are provided that suggest novel approaches to bring new ideas into clinical practice.

Brushing associated with oral irrigation in maintaining implants and overdentures hygiene - a randomized clinical trial

Evaluate, through a randomized clinical trial, the efficacy of brushing associated with oral irrigation in maintaining implant and overdenture hygiene. Thirty-eight participants, who had a clinically acceptable conventional maxillary complete denture and mandibular overdenture retained by either implants or mini-implants using an O-ring-retained system, were enrolled to participate in the study. They were instructed to use two different hygiene methods, in a random sequence for a period of 14 days, with a 7-day wash-out interposed period: (I) mechanical brushing (MB); (II) association of mechanical brushing with oral irrigation (WP). Biofilms from both subgingival sulci and overdentures were collected and processed by Checkerboard DNA-DNA hybridization method at baseline and after using the proposed hygiene protocols. Comparisons were performed using Wilcoxon test and Friedman test with Benjamini-Hochberg false discovery rate, followed by Conover post-hoc test (α = 0.05). In the subgingival sulci-related biofilm, a lower number of microbial cells were detected, after WP compared to the MB method (P < 0.001). The findings of overdenture-related biofilm suggest that both methods were similar (P = 0.607) being the identified microbiota qualitatively coincident after each method. Despite the number of microbial counts, it was concluded that the association of mechanical brushing with oral irrigation was more effective in reducing microorganisms in the subgingival sulci biofilm; however, the same outcome was not observed in the overdentures.

Evaluation of new Seawater-based Mouth Rinse Versus Chlorhexidine 0.2% Reducing Plaque and Gingivitis Indexes. A Randomized Controlled Pilot Study

For a long time, Chlorhexidine digluconate (CHX) has been considered the most used mouth-rinse for reducing plaque and gingivitis. Sea4® Encias is a new seawater-based mouth rinse with a similar action to CHX. Its prolonged use produces fewer side effects. This study compared the effects of two oral rinses: Chlorhexidine 0.20% and Sea 4® Encias (seawater) for reducing plaque and gingivitis indices. This double-blind crossover study recruited and monitored 93 volunteer dental students, hygienists and doctors from the Universidad Católica de Murcia (UCAM), for 1 month, and compared the efficacy of Chlorhexidine 0.20% (Group A); Sea4® Encías (Group B); and a placebo saline solution (Group C) mouth-rinses for reducing plaque and gingivitis indices. Plaque and gingival inflammation (Löe and Silness test) were evaluated at baseline and after each study stage. Group A reduced plaque growth and gingivitis significantly compared with Groups B and C; Group B was more effective than Group C. The mean P.I. decreased similarly in groups A and B. However, Group A showed the statistically significant value compared with other groups. Group A and group B, showed greater reduction in Gingival Indexes compared with group C. The Sea4 mouthwash showed better inhibitory activity on plaque (1.32 ± 0.22) compared with CHX (1.97 ± 0.34) and saline (2.78 ± 0.11). Sea4 Encias and Chlorhexidine 0.20% mouth-rinses significantly reduce plaque growth and G.I. compared with saline mouth-rinse; Sea4 Encías mouth-rinse is more effective against plaque regrowth than Chlorhexidine in this pilot study.

Orthodontic treatment as an adjunct to periodontal therapy

This study discusses the role of orthodontic treatment as an adjunct to the control and treatment of periodontal disease conditions, and describes a clinical case of severe anterior mandibular crowding and periodontal disease followed up for nine years and three months after orthodontic treatment completion. Malocclusion impaired proper dental hygiene, which led to bone loss and development of a periodontal abscess between mandibular canines and lateral incisors. After scaling and root planing, orthodontic treatment was initiated with extraction of the four second premolars, to correct the deficiency detected in cephalometric and model analysis. Treatment objectives were met, and facial and dental esthetics was satisfactory. Adequate periodontal management, hygiene control and tooth movement ensured ideal occlusion and facilitated the control of biofilm.

Effect of an Experimental Formulation Containing Chlorhexidine on Pathogenic Biofilms and Drug Release Behavior in the Presence or Absence of Bacteria

(1) Background: For any antibacterial oral formulation to be successful, it must present effects in the presence of biofilms. Therefore, our aim is to analyze the drug release and the antibiofilm effects of a semi-solid formulation containing chlorhexidine (CHX) in the presence of pathogenic biofilms. (2) Methods: The biofilms of Streptococcus mutans (n = 6) or Porphyromonas gingivalis (n = 3) were formed for 6 and 4 days, respectively, being exposed to: 1) a CHX system or 2) vehicle control without CHX. A group without treatment was included as negative control. The acidogenicity, CHX quantification and bacterial viability were determined. A dissolution assay in a buffer and culture medium in the absence of bacteria was also performed. (3) Results: Although the CHX quantification in the culture medium of both biofilms was lower compared to the buffer (p < 0.05) and the culture medium in the absence of bacteria, the CHX system was able to display antibiofilm effects until 96 h for the S. mutans biofilms (p < 0.05) and 72 h for the P. gingivalis biofilms (p < 0.05). (4) Conclusions: The experimental formulation is able to extend chlorhexidine effects, even in challenging conditions such as in the presence of bacteria, allowing the in vitro control of cariogenic biofilms for 4 days and periodontopathogenic biofilms for 3 days.

Efficacy of Three Types of Plaque Control Methods During Fixed Orthodontic Treatment: A Randomized Controlled Trial

Aim:

The aim of this study was to evaluate and compare the efficacy of three types of plaque control methods among 13- to 35-year-old subjects receiving fixed orthodontic treatment in Coorg Institute of Dental Sciences, Virajpet, Coorg district, Karnataka, India.

Materials and Methods:

A total of 111 subjects who fulfilled the inclusion and exclusion criteria were randomly included in the study. The subjects were recalled after 1 month of the commencement of fixed orthodontic treatment for the recording of baseline data including plaque index (PI), gingival index (GI), and modified papillary bleeding index (MPBI). After recording of the baseline data, the subjects were randomly allocated into each of the intervention groups, i.e., group A (manual tooth brush), group B (powered tooth brush), and group C (manual tooth brush combined with mouthwash) by lottery method. Further, all the subjects were recalled after 1 and 2 months for recording the data.

Results:

Regarding plaque levels, it was seen that there was a highly statistically significant difference between the three groups (P = 0.001), with the manual tooth brush combined with chlorhexidine mouthwash group recording the lowest mean PI score of 0.5 ± 0.39. A comparison of the mean GI scores among the groups at the end of 2 months shows a highly statistically significant difference (P = 0.001). The mean MPBI scores at the end of 2 months were highly statistically significant among the three groups (P = 0.001), with the group C recording the lowest mean MPBI score of 0.3 ± 0.3.

Conclusion:

The powered tooth brush group subjects exhibited significantly lesser PI, GI, and MPBI scores than the manual tooth brush group at the end of 2 months, whereas the manual tooth brush combined with chlorhexidine mouth wash group subjects showed maximum improvement, having significantly lesser PI and GI scores than the powered tooth brush group.

Oral antiseptics and nickel-titanium alloys: mechanical and chemical effects of interaction

The effect of oral antiseptics on the corrosion of nickel-titanium (NiTi) alloys with various coating was investigated. Uncoated, titanium nitride-coated and rhodium-coated NiTi archwires (0.020 × 0.020″) were tested in interaction with artificial saliva pH 4.8 and oral antiseptics based on hyaluronic acid (Gengigel), chlorhexidine (Curasept) and essential oils in alcohol base (Listerine). The dynamics of nickel and titanium ions release were recorded during 28 days. Springback ratio and modulus of resilience were assessed by three-point bending test. The results showed that corrosion of NiTi is related to type of antiseptic mouth rinse and coating formulations. Exposure to an artificial saliva and antiseptics tend to reduce flexibility and resilience of NiTi archwires. The influence of the media is more significant than the influence of the type of the alloys coating. The largest release of nickel ions is in the first 3 days. Antiseptics do not cause further deterioration of the elastic properties in uncoated NiTi compared to saliva. As a result of exposure of nitrified NiTi wires in Listerine, there is bigger release of nickel ions, decrease in elastic properties and lower force delivery in unload. Listerine tends to reduce elastic properties of rhodium-coated wires also. In conclusion, except for Listerine, changes of mechanical characteristics induced by antiseptics are small and would not have a clinically important impact. Generally, Curasept would be the most suitable option.

In vitro studies of the antimicrobial effect of non-thermal plasma-activated water as a novel mouthwash

The aim of this study was to evaluate the antimicrobial effects of non-thermal plasma-activated water (PAW) as a novel mouthwash in vitro. Three representative oral pathogens - Streptococcus mutans, Actinomyces viscosus and Porphyromonas gingivalis - were treated with PAW. The inactivation effect was evaluated using the colony-forming unit (CFU) method, and the morphological and structural changes of a cell were observed by scanning electron microscopy and transmission electron microscopy (TEM). The physicochemical properties of PAW were analysed, and its influence on the leakage of intracellular proteins and DNA was evaluated. The results showed significant reduction of Streptococcus mutans within 60 s, of Actinomyces viscosus within 40 s, and of Porphyromonas gingivalis in less than 40 s. Scanning electron microscopy and TEM images showed that the normal cell morphology changed by varying degrees after treatment with PAW. Intracellular proteins (280 nm) and DNA (260 nm) leaked from all three species of bacteria after treatment with PAW. Reactive oxygen species (ROS), especially atomic oxygen (O), hydroxyl radical (˙OH), and hydrogen peroxide (H₂ O₂ ), were generated and led to strong oxidative stress and cell damage. These results suggest that PAW has potential use as a novel antimicrobial mouthwash.

Nigella sativa and its active constituent thymoquinone in oral health

In this review, we summarized published reports that investigated the role of Nigella sativa (NS) and its active constituent, thymoquinone (TQ) in oral health and disease management. The literature studies were preliminary and scanty, but the results revealed that black seed plants have a potential therapeutic effect for oral and dental diseases. Such results are encouraging for the incorporation of these plants in dental therapeutics and hygiene products. However, further detailed preclinical and clinical studies at the cellular and molecular levels are required to investigate the mechanisms of action of NS and its constituents, particularly TQ.

Dynamics of Fluoride Bioavailability in the Biofilms of Different Oral Surfaces after Amine Fluoride and Sodium Fluoride Application

It was the aim of this study to investigate differences in fluoride bioavailability in different oral areas after the application of amine fluoride (AmF) and sodium fluoride (NaF). The null hypothesis suggested no differences in the fluoride bioavailability. The tongue coating was removed and biofilm samples from the palate, oral floor and cheeks were collected. All subjects brushed their teeth with toothpaste containing AmF or NaF. Specimens were collected before, as well as immediately after and at 30 and 120 minutes after tooth brushing. The fluoride concentration was determined. The area under the curve was calculated for each location and compared statistically. In the tongue coating, fluoride concentration increased faster after NaF application than after AmF application. After 30 minutes, the fluoride concentration decreased and remained stable until 120 minutes after AmF application and returned to baseline after NaF application. The difference between the baseline and the endpoint measurements was statistically significant. The fluoride concentration in the tongue coating remained at a higher level compared with the baseline for up to 120 minutes post-brushing. This may indicate that the tongue coating is a major reservoir for fluoride bioavailability. The results also indicate an unequal fluoride distribution in the oral cavity.

Effects of Antiseptic Solutions Commonly Used in Dentistry on Bone Viability, Bone Morphology, and Release of Growth Factors

PURPOSE

Antiseptic solutions are commonly used in dentistry for a number of sterilization procedures, including harvesting of bone chips, irrigation of extraction sockets, and sterilization of osteonecrotic bone. Despite its widespread use, little information is available regarding the effects of various antiseptic solutions on bone cell viability, morphology, and the release of growth factors.

MATERIALS AND METHODS

The antiseptic solutions included 1) 0.5% povidone iodine (PI), 2) 0.2% chlorhexidine diguluconate (CHX), 3) 1% hydrogen peroxide (H2O2), and 4) 0.25% sodium hypochlorite (HYP). Bone samples collected from porcine mandibular cortical bone were rinsed in the antiseptic solutions for 10 minutes and assessed for cell viability using an MTS assay and protein release of transforming growth factor (TGF-β1), bone morphogenetic protein 2 (BMP2), vascular endothelial growth factor (VEGF), interleukin (IL)-1β, and receptor activator of nuclear factor κB ligand (RANKL) using an enzyme-linked immunosorbent assay at 15 minutes and 4 hours after rinsing.

RESULTS

After antiseptic rinsing, changes to the surface protein content showed marked alterations, with an abundant protein layer remaining on CHX-rinsed bone samples. The amount of surface protein content gradually decreased in the following order: CHX, H2O2, PI, and HYP. A similar trend was also observed for the relative cell viability from within bone samples after rinsing, with up to 6 times more viable cells found in the CHX-rinsed bone samples than in the HYP- and PI-rinsed samples. An analysis of the growth factors found that both HYP and PI had significantly lower VEGF and TGF-β1 protein release from bone samples at 15 minutes and 4 hours after rinsing compared with CHX and H2O2. A similar trend was observed for RANKL and IL-1β protein release, although no change was observed for BMP2.

CONCLUSIONS

The results from the present study have demonstrated that antiseptic solutions present with very different effects on bone samples after 10 minutes of rinsing. Rinsing with CHX maintained significantly higher cell viability and protein release of growth factors potent to the bone remodeling cycle.

Antiseptic solutions modulate the paracrine-like activity of bone chips: differential impact of chlorhexidine and sodium hypochlorite

AIM

Chemical decontamination increases the availability of bone grafts; however, it remains unclear whether antiseptic processing changes the biological activity of bone.

MATERIALS AND METHODS

Bone chips were incubated with four different antiseptic solutions including (1) povidone-iodine (0.5%), (2) chlorhexidine diguluconate (0.2%), (3) hydrogen peroxide (1%) and (4) sodium hypochlorite (0.25%). After 10 min. of incubation, changes in the capacity of the bone-conditioned medium (BCM) to modulate gene expression of gingival fibroblasts was investigated.

RESULTS

Conditioned medium obtained from freshly prepared bone chips increased the expression of TGF-β target genes interleukin 11 (IL11), proteoglycan4 (PRG4), NADPH oxidase 4 (NOX4), and decreased the expression of adrenomedullin (ADM), and pentraxin 3 (PTX3) in gingival fibroblasts. Incubation of bone chips with 0.2% chlorhexidine, followed by vigorously washing resulted in a BCM with even higher expression of IL11, PRG4 and NOX4. These findings were also detected with a decrease in cell viability and an activation of apoptosis signalling. Chlorhexidine alone, at low concentrations, increased IL11, PRG4 and NOX4 expression, independent of the TGF-β receptor I kinase activity. In contrast, 0.25% sodium hypochlorite almost entirely abolished the activity of BCM, whereas the other two antiseptic solutions, 1% hydrogen peroxide and 0.5% povidone-iodine, had relatively no impact respectively.

CONCLUSION

These in vitro findings demonstrate that incubation of bone chips with chlorhexidine differentially affects the activity of the respective BCM compared to the other antiseptic solutions. The data further suggest that the main effects are caused by chlorhexidine remaining in the BCM after repeated washing of the bone chips.