Dentistry

Editorial Aditya Mitra, Chandrani Adhikari Journal of Conservative Dentistry 2019 22(2):107-107

Evaluation of the actual chlorine concentration and the required time for pulp dissolution using different sodium hypochlorite irrigating solutions Alfredo Iandolo, Alberto Dagna, Claudio Poggio, Ismail Capar, Alessandra Amato, Dina Abdellatif Journal of Conservative Dentistry 2019 22(2):108-113 Introduction: The goal of root canal treatment is to shape and clean the endodontic space, reducing the bacterial load and removing the pulp tissue. Obviously, the action of the endodontic instruments is limited to the main canals, regardless of the complexity of the endodontic space. Consequently, finding the best possible cleaning technique, which can be obtained chemically using irrigation solutions, is a fundamental aid in endodontic therapy. One of the most commonly used root canal irrigants is sodium hypochlorite (NaOCl), available in various commercial formulations. The effectiveness of NaOCl is undeniable. However, the action of dissolution of the pulp tissue is merely dependent on the concentration and the characteristics of the irrigant itself. Aim: The aim of this study is to evaluate the effective concentration of different commercial formulas of NaOCl, by evaluating the percentage of total chlorine in each product. The dissolution capacity of the pulp tissue of each of the tested products was then analyzed by measuring the required time. Materials and Methods: Three commercial types of NaOCl were selected for this study: 5% NaOCl (ACE, Procter and Gamble), 5% NaOCl (N5, Simit Dental), and 6% NaOCl (CanalPro, Coltene). For each product, 10 packages were used, from which samples of the product were taken and 30 ml × 5 ml tubes were filled. All samples were divided into three groups and were analyzed using the DIN EN ISO 7393-2 method and the percentage of total chlorine (expressed as a percentage) was calculated. Forty samples of vital pulp were obtained from teeth freshly extracted for periodontal reasons and stored in physiological solution. In order to unify the size and weight of the samples (0.0001 mg), a microtome and a precision balance (Pro Explorer Ohaus) were used. Each sample, carefully examined by stereomicroscope (×40), was placed in artificial plastic containers and submerged in 0.1 ml of irrigating solution at room temperature (26°C). A fourth control group used saline solution as irrigant. Simultaneously with the insertion of the irrigating solution, a digital stopwatch was activated and the time necessary for the complete dissolution of the pulp sample was measured. The data obtained was subjected to statistical analysis. Results: The average percentages of chlorine detected for each group were: 4.26% (ACE), 5.16% (N5), and 5.97% (CanalPro). The Kruskal–Wallis test showed statistically significant differences between the different commercial formulations of hypochlorite (P < 0.05). CanalPro showed the lowest values, whereas ACE showed the highest values of dissolution time of the pulp. Discussion: The analysis of the total chlorine percentage found that the actual concentration of the NaOCl in the samples is close to the values declared by the manufacturers both in the case of N5 and CanalPro. On the contrary, the concentration detected in the samples of common bench bleach (ACE) is significantly lower, which has average values <5%. This explains the longer time taken for the complete dissolution of the pulp tissue. The average dissolution time of the pulp samples was in fact inversely proportional to the concentration detected in the tested irrigants and hence that a lower time corresponds to a higher concentration.

Effectiveness of rotary and reciprocating systems on microbial reduction: A systematic review Riluwan Siddique, Malli Sureshbabu Nivedhitha Journal of Conservative Dentistry 2019 22(2):114-122 Introduction: The role of microorganism and their products in the initiation, propagation, and persistence of periradicular periodontitis has been established. One of the major goals of the treatment of infected root canals of teeth with apical periodontitis is to promote maximal reduction in the intracanal bacterial populations. Engine-driven nickel-titanium instruments possess the latest generation of root canal instruments. The possible benefit of rotary instrumentation over other instrumentation techniques regarding cleaning and disinfecting effects would be irrigant warming and/or turbulence caused by the mechanical rotation of instruments. Furthermore, reciprocating instrument has been introduced for root canal preparation. It has been shown that instruments subjected to reciprocation have increased resistance to fatigue and longer usual life when combined with instruments used in continuous rotation motion. The reciprocating system uses single-file instrumentation technique which can shape and clean the canal in a shorter period and together with the lesser amount of antimicrobial agent. Objective: The objective of this study is to compare and evaluate the microbial reduction of rotary and reciprocating systems on microbial reduction. Search Strategy: A search was performed in Electronic databases (i.e., PubMed, Cochrane library, Science direct, Lilac, Sigle) using following search terms alone and in combination by means of PubMed search builder from January 1985 to December 2017. Selection Criteria: Studies were selected if they met the following criteria: In vivo studies comparing rotary and reciprocating system in asymptomatic apical periodontitis patients. Main Results: The results showed that the reciprocating system exerted an almost similar antibacterial effect when compared with the rotary system. Conclusion: The present systematic review does not provide concrete evidence to show increased antibacterial efficacy of reciprocating system as compared to the rotary system. Furthermore, clinical trials are required to evaluate the efficacy of various instrumentation systems in reducing bacteria from the root canal system.

Probiotic Streptococcus strains in caries prevention: A systematic review Saravanan Poorni, Manali Ramakrishnan Srinivasan, Malli Sureshbabu Nivedhitha Journal of Conservative Dentistry 2019 22(2):123-128 Objective: The aim of this article is to review the published literature with the purpose of knowing the importance of using various probiotic Streptococcus strains as a preventive and therapeutic method for dental caries management. Materials and Methods: Research question was formulated based on the PICO strategy. A comprehensive electronic literature search was conducted across PubMed/Medline, Scopus, and EBSCOhost databases independently by two reviewers. All papers published from 1989 to December 2017 that focused on the use of probiotic Streptococcus strains for caries prevention were included in this review. Inclusion and exclusion criteria were applied to the selected articles, and a customized data extraction sheet was formulated. The selected articles were subjected to quality assessment, and the risk of bias in selected studies was evaluated. Results: A total of five articles were included. The overall risk of bias of the selected clinical trials was found to be high risk, and the overall level of evidence of the selected in vitro studies was moderate. Conclusion: The two included clinical studies on the use of probiotic Streptococcus strains for caries prevention had high risk of bias. Although in-vitro studies showed promising results, clinical studies have not demonstrated clear clinical outcomes. Thus, there is a vast scope for future research in this field. Clinical Relevance: Application of oral probiotics will help reinstate a balanced microbiota and thereby improving oral health. This systematic review focused on evaluating the role played by probiotic Streptococcus strains in the carious lesion incidence.

Success or failure of endodontic treatments: A retrospective study Airton Oliveira Santos-Junior, Lidiane De Castro Pinto, Jose Francisco Mateo-Castillo, Claudia Ramos Pinheiro Journal of Conservative Dentistry 2019 22(2):129-132 Context: Well-conducted endodontic therapy is necessary for the dental rehabilitation of the individuals with cleft lip and palate. Aim: The aim of this study was to verify the success and failure index of endodontic treatments performed in the Endodontic Sector of the Hospital for Rehabilitation of Craniofacial Anomalies, University of São Paulo, (HRAC/USP), Bauru, Brazil. Materials and Methods: The preservation records (at least 2 years) of the endodontic treatments performed in the HRAC/USP were verified, indicating the success or failure of the treatment, and these treatments were divided into three groups (vital pulp, necrotic pulp, and endodontic retreatment). The Chi-square statistical test was applied with a significance level of 5%. Results: A total of 1216 endodontic treatments were quantified with a minimum of 2 years of prenatal care at HRAC/USP. The vital pulp group had a success rate of 99.4% (535 treatments) and 0.6% failure (3 treatments), 98.6% of success in the necrotic pulp group (577 treatments) and 1.4% failure (8 treatments), and 95.6% success rate (89 treatments) and 4.4% failure (4 treatments) in the endodontic reintervention group. Conclusion: From the results found, we can conclude that there was a high success rate in the treatments and endodontic retreatments performed in the Endodontics Sector of the HRAC/USP, considering that well-conducted endodontic therapy is extremely important in the oral rehabilitation of individuals with cleft lip and palate.

Racial predilection of C-shaped canal configuration in the mandibular second molar Aishwarya Roy, Madhusudan Astekar, Rashmi Bansal, Anuraag Gurtu, Mrityunjay Kumar, Lalit Kumar Agarwal Journal of Conservative Dentistry 2019 22(2):133-138 Aim: The purpose of this article is to determine the racial predilection of C-shaped canal configuration in a mandibular second molar. Background: Unusual root canal anatomy always poses a diagnostic and treatment challenge. Identification of such variation is important for the success of root canal treatment outcome. C-shaped canal configuration is such an aberrant morphology of molar teeth that vary in different population and is commonly seen in a mandibular second molar. Thus, knowledge of racial predilection of C-shaped canal configuration in different population for early diagnosis is obligatory. Materials and Methods: An exhaustive search was undertaken to identify published research articles related to C-shaped canal configuration in mandibular second molars. Forty-three research articles were analyzed which included 12,481 mandibular second molars. Chi-square test using value of P < 0.05 was performed to assess the statistical significance of this anomalous anatomic variation among the different population. Results: Statistical test revealed a significant variation between the Asian and nonAsian population. The highest incidence of racial predilection was observed in China (Asia) with 93.1%, and the minimum was observed in America with 2.7%. Conclusion: This research reported that racial predilection of C-shaped canal configuration in mandibular second molar varies significantly.

Evaluation of the relationship between the maxillary sinus floor and the root apices of the maxillary posterior teeth using cone-beam computed tomographic scanning Svetlana Razumova, Anzhela Brago, Ammar Howijieh, Ashot Manvelyan, Haydar Barakat, Malina Baykulova Journal of Conservative Dentistry 2019 22(2):139-143 Background: The relationship between the maxillary sinus (MS) and the root apices of the posterior teeth is of clinical relevance in diagnosing and treatment planning in the posterior area of the maxilla. This study aimed to assess the relationship between the MS floor and the root apices of the posterior teeth using cone-beam computed tomography (CBCT) scanning. Materials and Methods: 325 CBCT scans of patients aged 20–70 years were analyzed. Patients were divided into three age groups: young group (20–44 years), middle age group (45–59 years), and elderly group (60–70). The distance from the MS floor and the root apices of posterior teeth was measured in each group. The relationship between the MS and the posterior roots was also recorded according to Kwak classification. The results were analyzed by IBM statistic SPSS. Results: Type II was most commonly seen in the first and second molars. For premolars, Type I was often observed. The shortest distance to the floor of MS was recorded for the mesiobuccal root of the second molar and the longest distance for the palatal root of the first and second molars. No statistical differences were found between age groups (P > 0.01). Conclusion: The anatomical relationship between the MS and the root apices of the posterior teeth is of clinical importance and should be taken into consideration during surgical or endodontic treatment.

Effect of proanthocyanidin and bamboo salt on the push-out bond strength of an epoxy resin sealer to sodium hypochlorite-treated root dentin: An in vitro study Palmoor Santosh Kumar, Anand Meganathan, Shanti Shriram, Vidhya Sampath, Mahalaxmi Sekar Journal of Conservative Dentistry 2019 22(2):144-148 Background: In endodontic therapy, final irrigation is often done with sodium hypochlorite (NaOCl). This jeopardizes the bond strength between the epoxy resin sealer, used subsequently in obturation and radicular dentin. This study aimed to analyze the effect of natural antioxidants, 6.5% proanthocyanidin (PA) and 25% bamboo salt (BS) on the reversal of NaOCl-induced reduced bond strength of an epoxy resin sealer to dentin. Materials and Methods: Thirty-three single-rooted extracted human teeth were randomly divided into three groups based on the final irrigation protocol: group 1 (saline), Group 2 (6.5% PA), and Group 3 (25% BS). The canals were cleaned, shaped, and obturated with gutta-percha and AH Plus sealer. 1.5 mm-thick root slices made from coronal, middle, and apical thirds of the canal were subjected to push-out bond strength (PBS) testing. The data were statistically analyzed using Kruskal–Wallis and Dunn's post hoc test (P < 0.05). Results: 5.25% NaOCl significantly decreased the bond strength of AH Plus to dentin (P < 0.05). Both 6.5% PA and 25% BS were capable of reversing the compromised PBS of AH Plus to NaOCl-treated dentin. Conclusion: Final irrigation with antioxidants such as PA and BS eliminates the risk of reduced bond strength of AH Plus to root canal walls, which ensues following the use of NaOCl as an irrigant.

Scanning electron microscopic evaluation of smear layer removal at the apical third of root canals using diode laser, endoActivator, and ultrasonics with chitosan: An in vitro study Sathish Abraham, Sneha Dhruvkumar Vaswani, Harshal Balasaheb Najan, Disha Lalit Mehta, Aradhana Babu Kamble, Salil Dinesh Chaudhari Journal of Conservative Dentistry 2019 22(2):149-154 Aim: The aim of this study was to compare the effect of diode laser, endoActivator, and passive ultrasonics for smear layer removal at the apical third from root canals with 0.2% chitosan. Materials and Methods: A total of 40 mandibular premolars were decoronated to establish a working length of 12 mm and shaped with ProTaper rotary files up to size F3. In Group A, canals were irrigated with 1 ml of 0.2% chitosan. In Group B, canals were initially irrigated with 0.8 ml of 0.2% chitosan and the remaining 0.2 ml was activated with diode laser. In Group C, canals were irrigated with 1 ml of 0.2% chitosan which was activated with endoActivator. In Group D, canals were irrigated with 0.2% chitosan and activated with passive ultrasonics. All samples were finally flushed with 3 ml of distilled water. The percentage of smear layer removal was analyzed with a scanning electron microscope examination at ×1000 and ×3000. Data were analyzed using Statistical Package for the Social Sciences version 16.0 (SPSS Inc., Chicago, IL, USA) at a significance level of P < 0.05. Results: The mean value for Group B when compared to Group C for the removal of smear layer was higher, but there was no statistically significant difference between the two groups (P < 0.068 and P < 0.295). Both Group B and Group C showed a statistically significant difference (P < 0.001) when compared to Group A and Group D for the removal of smear layer. Conclusion: Diode laser and endoActivator with 0.2% chitosan proved better in the removal of the smear layer when compared to passive ultrasonic irrigation.

Efficacy of passive ultrasonic irrigation, continuous ultrasonic irrigation versus irrigation with reciprocating activation device in penetration into main and simulated lateral canals Caio Cesar Souza, Carlos Eduardo Bueno, Augusto Shoji Kato, Ana Grasiela Limoeiro, Carlos Eduardo Fontana, Rina Andrea Pelegrine Journal of Conservative Dentistry 2019 22(2):155-159 Context: The use of chemicals solutions and means of activation is of utmost importance in endodontic treatment. Aims: This study compared three activation techniques used in the final irrigation of the endodontic treatment. Subjects and Methods: Eighty uniradicular teeth were instrumented with the Protaper Universal system up to F4 file. After decalcification, the teeth had artificial lateral canals created at 2, 4.5 and 6 mm from working length (WL). The groups were randomly divided into four groups (n = 20): control group (C), passive ultrasonic irrigation (PUI) group, continuous ultrasonic irrigation (CUI) group, and easy clean (EC) group. The penetration of the irrigant into the samples was evaluated using image observation using the Image J program. Statistical Analysis Used: The level of agreement among the observers was determined by the Cronbach's alpha test. The likelihood ratio test was used to evaluate possible differences between the groups and the Kendall's W statistic test to verify possible differences between the irrigant penetration levels in the lateral canals. The Fisher's exact test was applied to verify differences by the studied group considering the WL variables and lateral canals. Results: The results showed no statistical difference in the penetration of the irrigator in the main canal when compared to the C, PUI, CUI, and EC groups (P > 0.05). Conclusions: The method using a positive syringe and needle pressure was not able to effectively carry the irrigator to the artificially made lateral canals, whereas PUI, CUI, and EC were equally efficient in this regard (P < 0.01).