Compatibility of Dual Rinse HEDP with Sodium Hypochlorite Solutions Containing Proprietary Additives.

INTRODUCTION: A salt of 1-hydroxyethylidene-1,1-diphosphonic acid was commercialized some years ago. This so-called Dual Rinse HEDP has been tested for its combined actions and interactions with pure NaOCl solutions. The aim of this study was to assess Dual Rinse interactions with NaOCl solutions containing proprietary additives. METHODS: Designated endodontic NaOCl solutions that come at 2 different strengths (2% and 5.25%), and without or with additives (Chloraxid and Chloraxid Extra, respectively) were tested. Some of their key chemical and physical properties were determined in the presence or absence of HEDP (9%) in the solution. In addition, soft tissue dissolution efficacy of test and control solutions was assessed in extracted teeth (n = 10 per group, 90 teeth in total). RESULTS: The NaOCl content in the 2% Chloraxid solutions was slightly above, that in the 5.25% solutions below the labelled concentration. The additives in the Chloraxid Extra solutions neither altered their surface tension, nor their viscosity. The addition of HEDP to any of the tested NaOCl solutions reduced their pH, and increased their surface tension and viscosity. HEDP-induced available chlorine loss over the first hour was similar between all NaOCl solutions. Soft tissue dissolution in the root canals was affected by NaOCl concentration, but neither by any proprietary NaOCl additive in the Chloraxid solutions, nor the addition of Dual Rinse HEDP. CONCLUSIONS: Proprietary additives had no influence on any of the tested parameters, including surface tension of the "Extra" solutions. The increased viscosity of combined NaOCl/HEDP solutions deserves further attention.

Evaluation of New Alkasite Based Restorative Material for Restoring Non- Carious Cervical Lesions- Randomized Controlled Clinical Trial.

Two different restoration materials, an alkasite-based resin composite and a resinmodified glass ionomer cement were used to assess restoration of non-carious cervical dental lesions. This split mouth randomized controlled trial included 40 patients. After randomization both sides of the dental arch were restored with either an alkasite-based (Cention N, Ivoclar Vivadent) or a resin-modified glass ionomer cement (Voco GmbH) restoration. The placed fillings were evaluated by blinded additional operators 1, 6 months and 1 year after to the USPHS criteria (retention, marginal integrity and discoloration, anatomical form and secondary caries). Data were analyzed using Kendall's Coefficient of Concordance test and Chi-square tests using SPSS software (SPSS Inc., Version 20) (P=0.05). As for retention and anatomic form both materials performed similar after one month. However, the retention and anatomic form for alkasite based restorative Cention showed significantly better results after 6 months (p=0.013/p=0.003) and one year (p=0.026/p=0.008). The resin modified glass ionomer restoration showed higher discoloration after 6 months (p=0.025) and one year (p=0.018), while Cention performed better regarding marginal integrity at all time intervals. No secondary caries occurred. Alkasite based restorative materials displayed superior technical, mechanical and aesthetical performance in a follow-up period of one year and can therefore be recommended as an alternative to resin-modified glass ionomer cements.

MMP-9 Levels and NaOCl Lavage in Randomized Trial on Direct Pulp Capping.

Outcome expectations of direct pulp capping in carious teeth are obscured by a clinically unknown infiltration and breakdown of the dental pulp tissue. Histologic studies showed that this soft tissue breakdown is related to the innate immune system. We hypothesized 1) that a neutrophil biomarker could predict the outcome of direct pulp capping and 2) that using sodium hypochlorite (NaOCl) as a lavage solution to remove necrotized infected pulp tissue could improve it. In this randomized trial in mature posterior teeth causing no or mild discomfort with carious pulpal exposures, pulpal fluid was collected to assess neutrophil gelatinase (matrix metalloproteinase 9 [MMP-9]) per total protein (TP) levels as a predictive local biomarker. Subsequently, the dentin-pulp wound was randomly washed with a 2.5% NaOCl or a physiologic saline solution (1:1 allocation), capped with mineral trioxide aggregate, and the tooth was immediately restored with a resin-based composite restoration. Ninety-six patients were included, and 84 individuals could be followed up to treatment failure or clinically confirmed pulp survival after a minimum of 1 y. The entire data were fitted to a Cox proportional hazards model to assess the influence of the observational variables MMP-9/TP and discomfort with the randomized lavage treatment on pulp survival. The Kaplan-Meier pulp survival rates after 1 y were 55% for saline and 89% for NaOCl lavage. The inflammatory state of the pulp tissue as reflected by MMP-9/TP levels and NaOCl lavage had a highly significant (P < 0.001 and P = 0.004, respectively) impact on pulp survival, while mild preoperative discomfort did not. In conclusion, MMP-9/TP showed great promise as a predictive local biomarker, and NaOCl lavage considerably improved the survival time of cariously exposed and directly capped pulps.

Antimicrobial activity, toxicity and accumulated hard-tissue debris (AHTD) removal efficacy of several chelating agents.

AIM: To evaluate the antimicrobial, toxicity and cleaning effectiveness of ethylenediaminetetraacetic acid (EDTA) and maleic acid (MA) alone and combined with cetrimide (CTR). METHODOLOGY: Cytotoxic and genotoxic effects were assessed on Chinese hamster cells V79 using the MTT, clonogenic and micronucleus assays, respectively. The bacterial inhibitory and bactericidal concentrations (MIC and MBC, respectively) were determined on a strain of Enterococcus faecalis. Antimicrobial tests were performed on a biofilm model after treatment with the chelating agents by using a biofilm eradication concentration (MBEC) and confocal laser scanning microscope (CLSM) assays. Quantification of cell biomass and percentage of live and dead cells in the biomass were assessed for each group. The percentage reduction of accumulated hard-tissue debris (AHTD) after root canal preparation and final irrigation protocols was evaluated by micro-CT. Statistical tests of one-way analysis of variance (anova), Bonferroni test, Kruskal-Wallis test, Dunn's multiple comparison test and Wilcoxon matched-pairs signed-rank tests were used. RESULTS: Cetrimide alone as well as in combination with EDTA and MA at dilutions of 1/10 and 1/100 was significantly more toxic as compared to untreated controls (P < 0.001). All tested mixtures were nontoxic at a dilution of 1/1000. EDTA retained a weak inhibitory and bactericidal effect against planktonic cells, whilst MA inhibited cells growth and killed 99.9% of the cells when diluted. CTR revealed the most prominent effect, being inhibitory and bactericidal, also when diluted. Cetrimide alone or combined with EDTA was able to remove, respectively, 40% (P < 0.01) and 60% (P < 0.001) of the entire biomass after 1 min. Conversely, MA alone and in combination with CTR did not have a significant effect on biomass reduction. After final irrigation, the AHTD volume was significantly decreased in all groups (P < 0.05). EDTA + CTR and MA + CTR were associated with a significant reduction in the percentage of AHTD on the entire root canal compared to the same solutions without surfactant. CONCLUSIONS: 7% MA was less cytotoxic in comparison with 17% EDTA. The addition of cetrimide to EDTA and MA removed accumulated hard-tissue debris effectively from the canal walls and increased their antimicrobial activity when compared to the same solutions without detergents.

Safety assessment of an etidronate in a sodium hypochlorite solution: randomized double-blind trial.

AIM: To assess whether Dual Rinse HEDP, an etidronate that can be combined with NaOCl to create an endodontic irrigating solution containing both hypochlorite and a chelator in the form of 1-hydroxyethane 1,1-diphosphonic acid (HEDP), alters the clinical efficacy of NaOCl or adds any untoward clinical effects. METHODOLOGY: In this randomized controlled double-blind single-centre trial, a pure NaOCl solution was compared to a HEDP-containing counterpart regarding antimicrobial efficacy, postoperative pain, and the host response by means of changes in MMP-9 levels in periapical fluid. Sixty patients presenting with asymptomatic apical periodontitis (one tooth each) were randomly divided into two groups (N = 30) based on irrigation regime. Pre- and post-treatment microbial aerobic and anaerobic cultures and MMP-9/total protein (TP) periapical fluid samples were collected. Postoperative pain levels were assessed 24 h after treatment. Categorical data were compared between groups using the Fisher's exact test, continuous data using the Wilcoxon signed-rank test, α = 0.05. RESULTS: Irrigation with pure NaOCl rendered 40% canals free of culturable microorganisms, compared to 50% with the NaOCl/HEDP mixture (P = 0.60). As assessed by matrix-assisted laser desorption/ionization-time-of-flight analysis (MALDI-TOF), no apparent selection of aerobic or anaerobic taxa occurred in either group. One patient in the NaOCl group experienced moderate pain, whilst two patients in the NaOCl/HEDP group experienced mild postoperative pain. MMP-9/TP levels in periapical fluid declined significantly (P < 0.001) after 1 week with no medication in the root canal, without significant difference between treatment groups (P > 0.05). CONCLUSIONS: This trial found no influence of HEDP on clinical NaOCl effects.

Chemical, cytotoxic and genotoxic analysis of etidronate in sodium hypochlorite solution.

AIM: To test whether the incorporation of a chelation powder, etidronate, marketed for root canal irrigation (Dual Rinse HEDP) into a sodium hypochlorite (NaOCl) solution induced additional cytotoxic and genotoxic effects not observed with NaOCl alone. METHODOLOGY: Fresh and 24-h-old mixtures of 0.9 g of etidronate in 10 mL of 2.5% NaOCl were assessed for their basic chemical features including pH and the ability to chelate Ca2+ from hydroxylapatite. Pure NaOCl and phosphate-buffered saline (PBS) with/without etidronate served as control solutions. Cytotoxic and genotoxic effects of diluted solutions (1:10, 1:100, and 1:1000) were assessed on Chinese hamster lung fibroblast (V79) using the MTT, clonogenic and micronucleus assays, respectively. One-way ANOVA and Tukey's HSD test were applied with an alpha-type error of 5% (P < 0.05). RESULTS: In mixtures of NaOCl and etidronate, the free available chlorine was lost completely after 24 h, and the pH dropped by more than 3 units. However, the ability of the etidronate to chelate Ca2+ was maintained. The fresh mixtures of NaOCl and etidronate were not more toxic than NaOCl alone (P > 0.05), whilst the 24-h-old mixtures were less toxic (P < 0.05) and statistically similar to pure etidronate. Etidronate per se showed little cytotoxicity and no genotoxicity at the tested dilutions. CONCLUSIONS: The ability of the used etidronate, Dual Rinse HEDP, to chelate calcium is not affected by NaOCl. Cytotoxicity and genotoxicity of mixed solutions is dictated by the presence of free available chlorine therein.

Comparative Evaluation of Surface Defects In Single File Rotary Systems Before and After Instrumentation In Curved Root Canals.

This study aims to evaluate the surface defects and efficiency of two single file rotary systems with different surface treatments in curved root canal instrumentation. A total of 160 root canals were randomly divided into two groups and were subjected to root canal instrumentation with electropolished surface rotary file (Group 1) and with EDM surface treated rotary file (Group 2). All the files were then subjected to SEM analysis to evaluate the surface defects prior to the root canal instrumentation,after 5 uses and 8 uses inside the root canal. From the scanning electron microscopic images, the surface defects as observed were scored and were statistically analyzed. SEM analysis of both the single file systems revealed significantly varying surface defects. Rotary file with electropolishing appeared to be more resistant to deformation compared to the rotary file with EDM treatment after instrumentation of five canals. Hence it can be concluded that electropolished file can be safely instrumented for five times compared to EDM processed files in curved root canals.

Effect of maleic acid and ethylenediaminetetraacetic acid on the shear bond strength of RealSeal SE sealer to root canal dentin.

Aim of this study was to evaluate the effect of 7% maleic acid and 17% ethylenediaminetetraacetic acid (EDTA) on the shear bond strength of RealSeal SE sealer to root canal dentin. Twenty incisors were split into coronal, middle and apical third and were treated in the following manner: Group 1: 5 ml of saline (1 minute). Group 2: 2.5% sodium hypochlorite (5 ml/min) followed by 79% maleic acid (5 ml/min). Group 3: 2.5% sodium hypochlorite (5 ml/min) followed by 17% EDTA (5 ml/min). Sealer was the placed on the root dentin and samples were subjected to bond strength measurement. There was no significant difference in bond strength between maleic acid and 17% EDTA in coronal & middle third. However, in apical third, 7% maleic acid showed higher bond strength. Least bond strength was observed with saline. Bond strength was maximum in apical third for both 7% maleic acid and 17% EDTA.

Comparative evaluation of different chelators in removal of calcium hydroxide preparations from root canals.

BACKGROUND: This study compared the efficacy of 10% citric acid, 17% EDTA and 7% maleic acid (MA) with ultrasonic agitation in the removal of calcium hydroxide (CH) from root canals. METHODS: Seventy maxillary anterior teeth were enlarged to F3 using protaper files. Teeth were then divided into two groups: A and B. Group A was filled with (CH + iodoform + silicone oil) mixture and group B with CH and propylene glycol (PG). Ten teeth were divided into positive and negative control groups. The volume of CH preparations was estimated using spiral CT. After seven days, teeth in groups A and B were further divided into three subgroups based on irrigants used and CH was retrieved along with ultrasonic agitation. Volume analysis was undertaken using spiral CT. Mean percentage of CH removed was analysed using one-way ANOVA followed by Tukey's Honestly Significant Difference test. RESULTS: All irrigants removed (CH + PG) completely without any difference between them (p = 0.17). Removal of (CH + iodoform + silicone oil) was significantly higher for MA and citric acid than EDTA (p < 0.001). There was no difference between MA and citric acid. CONCLUSIONS: Concentrations of 7% MA and 10% citric acid were found to be superior to 17% EDTA in the removal of (CH + iodoform + silicone oil). (CH + PG) preparation was completely removed by all the irrigants.

Effect of maleic acid and ethylenediaminetetraacetic acid on the dissolution of human pulp tissue--an in vitro study.

AIM: To compare in vitro, the tissue-dissolution capacity of 7% maleic acid (MA), 17% ethylenediaminetetraacetic acid (EDTA), 2.5% sodium hypochlorite (NaOCl) (positive control) and 0.9% saline (NaCl) (negative control) on human pulp tissue. METHODOLOGY: Forty pieces of human pulp tissue, each weighing 0.026 g, were divided randomly into four groups (n = 10): (i) 7% MA solution, (ii) 17% EDTA solution, (iii) 2.5% NaOCl solution and (iv) 0.9% NaCl solution. The pulp tissue was placed in beakers containing the test solutions and then placed on a vibrator. Pulp tissue from the four experimental solutions was blotted dry and weighed after 30, 60, 90 and 120 min. The percentage of weight loss was calculated, and the data were statistically analysed using Kruskal-Wallis and Mann-Whitney U-test. RESULTS: At all time intervals, 2.5% NaOCl dissolved pulp tissue significantly more than the other solutions (P < 0.001). There was no significant difference in the pulp-dissolution capacity between 7% MA and 17% EDTA at any of the time intervals. NaCl (0.9%) did not have any effect on pulp tissue. CONCLUSION: Seven percentage of MA and 17% EDTA had minimal tissue-dissolution capacity when compared to NaOCl.

Susceptibility of Candida albicans and Enterococcus faecalis to Chitosan, Chlorhexidine gluconate and their combination in vitro.

The aim of the present study was to analyse the sustain release of Chlorhexidine with Chitosan and to investigate the antimicrobial activity of 2% Chlorhexidine gel, 2% Chitosan gel and their combination against Candida albicans and Enterococcus faecalis. Sustain release of Chlorhexidine with Chitosan was determined using UV spectrophotometer. Then the inoculae of these organisms were used to make the lawn culture on sabouraud's dextrose agar and blood agar plates. Wells were prepared in these lawn cultures and filled with 2% Chlorhexidine gel, 2% Chitosan gel and their combination. The agar plates were incubated overnight at 37 degrees C and the zone of inhibition was examined after 48 h. Release of Chlorhexidine with Chitosan was better than plain Chlorhexidine release. Combination of Chlorhexidine and Chitosan showed maximum inhibitory zone for C. albicans (25.2 mm) and E. faecalis (26.0 mm). Plain Chlorhexidine gel showed intermediate inhibitory zone for C. albicans (20.6 mm) and E. faecalis (21.4 mm) and plain Chitosan gel showed minimum inhibitory zone for C. albicans (16.6 mm) and E. faecalis (11.0 mm). Carbopol which served as control did not have any antimicrobial effect. The present study suggests that 2% Chlorhexidine gel in combination with 2% Chitosan gel has the highest antimicrobial effect against C. albicans and E. faecalis compared with 2% Chlorhexidine gel or 2% Chitosan gel alone.

Salvaging a tooth with a deep palatogingival groove: an endo-perio treatment--a case report.

AIM: To describe the diagnosis and management of tooth 22 with a necrotic pulp and severe periodontal destruction associated with a deep palatogingival groove extending to the root apex. SUMMARY: Palatogingival grooves are uncommon in maxillary lateral incisors, but when present may contribute to the pathogenesis of periodontal and endodontic lesions. In the present case, the prognosis was considered poor, as the patient presented with a deep probing defect, advanced bone loss and grade III mobility of tooth 22. Root canal treatment was performed, followed by periodontal surgery, during which the groove was conditioned and sealed with conventional glass-ionomer cement and the osseous defect filled with indigenously prepared hydroxyapatite. The 18 month post-operative follow up showed substantial resolution of the osseous defect with gain in attachment and decreased tooth mobility. KEY LEARNING POINTS: Teeth with deep palatogingival grooves may be significantly compromised with severe periodontal and periapical bone loss. Following thorough evaluation, the careful application of endodontic and periodontal surgical procedures may restore satisfactory function.