Global variations in eruption chronology of permanent teeth: A systematic review and meta-analysis

OBJECTIVES

Population-based variations have been reported in permanent teeth eruption but only sparse literature exists on the same. A systematic review and meta-analysis were performed to assess the global variations in eruption chronology of permanent teeth in children and adolescents and the role of sexes, jaws and classes of socio-economic status (SES) on timing of eruption was explored.

METHODS

The protocol for the systematic review was registered in PROSPERO. An extensive search of PubMed, EMBASE, Google Scholar, EBSCO, Cochrane library, and anthropology databases was carried out until April 2023. Additionally, grey literature search and hand-searching of relevant key journals was done.

RESULTS

Overall, 3797 cross-sectional and longitudinal studies were retrieved from multiple databases. A total of 939, 191 participants were included from 80 studies of which, 41 were carried out in Asia, 26 in Europe, 5 in Africa, 4 in North America, and 4 in Oceania. The mandibular first molar eruption was found to be as early as 4.09 years while the maxillary second molar erupted as late as 13.45 years. Using a random effects model, 28 forest plots were generated. Meta-regression interpreted tooth eruption to be earlier in females and in the mandible.

CONCLUSIONS

The findings of this study show that the ages of permanent teeth eruption was advanced in the European population followed by Africa and Asia.

Global variations in eruption chronology of primary teeth: A systematic review and meta-analysis

OBJECTIVES

This systematic review aimed to assess global variations in the eruption chronology of primary teeth in children and the role of sexes, jaws, and socio-economic status on eruption timing.

DESIGN

An extensive search of electronic databases, grey literature, and hand-searching was carried out until April 2023 RESULTS: A total of 42,109 children, with an age range of 0-83 months were included from 42 studies (22 in Asia, 7 in Europe, 5 in Africa, 4 in North America, 3 in Oceania and 1 in South America). The mandibular central incisor was the first tooth to erupt at 6 months in North America and 13.5 months in Asia while the mandibular second molar erupted at 20.1 months in Europe and 29 months in South America.

CONCLUSIONS

The age of primary teeth eruption was advanced in the European population followed by North America, Africa, Oceania, and Asia while it was delayed in the South American population. Meta-analysis showed that tooth eruption was earlier in the left quadrant than the right but the role of other factors (sexes, jaws, and socio-economic status) was insignificant. Population-specific data on primary teeth emergence may serve as a baseline for future research. In clinical practice, these population-based eruption charts can serve as a valuable asset for diagnosis and treatment planning in children.

OXIS Contacts as a Risk Factor for Approximal Caries: A Retrospective Cohort Study

Purpose: The purpose of the present study was to evaluate the individual susceptibility of four different types of OXIS contact areas (open [O], point [X], straight [I], and curved [S]) to approximal caries in children. Methods: A retrospective cohort study was performed using clinical photographs and cone-beam computed tomography images of children, available from January 1, 2014, to August 31, 2015, showing the presence of at least one caries-free contact area between the primary molars. A single calibrated examiner scored 1,102 selected contacts using OXIS criteria from the occlusal view and subsequently evaluated the same contacts with a minimum follow-up period of one year for the presence of approximal caries. Results: Of the 1,102 contacts, 259 (23.5 percent) were found to be carious or restored due to approximal caries. Multivariate logistic regression analysis showed that only the type of contact played a significant role in caries prevalence (P<0.05). The odds ratios of OXIS contacts for the development of approximal caries were: S contact-147.4 (95 percent confidence interval [95% CI] equals 19.7 to 1101.7); I contact-24.5 (95% CI equals 3.4 to 177.9); X contact-1.1 (95% CI equals 1.0 to 12.5); and O contact-1.00 (reference). Conclusions: Among the OXIS contacts, the S type was most susceptible to approximal caries due to its complex morphology. The broad contact areas, namely, I and S types, are at greater risk for approximal caries in primary molars than O and X contacts.

Root canal isthmi and interorifice distance in human permanent teeth of an Indian subpopulation using cone-beam computed tomography: A retrospective cross-sectional study

Objective:

The aim of the study was to evaluate the prevalence of root canal isthmus (RCI) and measure the interorifice distance (IOD) between the root canals. Additionally to correlate IOD with the RCI in human permanent teeth using conebeam computed tomography (CBCT) in an Indian sub-population (Chennai).

Materials and Methods:

A total of 5881 teeth from 280 CBCT full mouth scans were analyzed. The presence or absence of complete and incomplete RCI of each tooth was identified using the map-reading strategy. IOD was calculated by measuring the distance between the center of each root canal orifice to that of the center of the adjacent orifice at the level of the cementoenamel junction using the axial and sagittal sections. Chi-square analysis and correlation statistics using Spearman's rank-order test was done (P < 0.05).

Results:

High prevalence of RCI was found in maxillary first premolars, mesial root of mandibular molars, and mesiobuccal root of maxillary first molars, while its prevalence was low in maxillary canines and mandibular premolars and absent in maxillary incisors. RCI was predominantly seen in the cervical and middle third of the root canal in all the teeth evaluated. A weak negative correlation was established between the IOD and RCI for maxillary premolars, whereas a weak positive correlation was seen in maxillary first molars and mandibular second molars.

Conclusion:

The prevalence of RCI was high in the posterior teeth in comparison to the anterior teeth in the present study. There was no strong correlation between IOD and RCI in all the teeth evaluated.

Impact of different modes of school dental health education on oral health-related knowledge, attitude and practice behaviour: an interventional study

PURPOSE

The study was planned to evaluate the effectiveness of three modes of school dental health education (SDHE) on the oral health-related knowledge, attitude and practice (KAP) behaviour of school children.

METHODS

An interventional study was carried out among 8-9 year old school children from January 2016 to January 2018. Three hundred and sixty children from three schools in Tiruchengode, Tamil Nadu, India participated in this study. Each school was randomly allotted with a mode (drama, modified snake and ladder game, flashcard) of SDHE, which was delivered for 20 min, every 6 months for 2 years. A validated questionnaire with 18 questions was used to record oral health-related KAP behaviour at baseline and after 2 years.

RESULTS

At the end of 2 years, there was an increase in the percentage of correct response for all the nine knowledge questions, in all the three modes. The mean difference in the cumulative knowledge score between baseline and 2 years was 1.39 ± 2.05 for drama mode, 1.8 ± 1.51 for game mode and 1.7 ± 1.5 for flashcard mode of SDHE. There was a significant difference in three knowledge questions and one attitude practice behaviour question between the three groups at the end of 2 years.

CONCLUSIONS

All the three modes were effective in improving the oral health-related KAP behaviour of school children. Game mode made a better impact on the knowledge scores of these children, and it was observed to be more child-friendly and entertaining.

Effectiveness of school dental health education on the oral health status and knowledge of children: A systematic review

Objective

To evaluate the effectiveness of school dental health education on the oral health status, oral health-related knowledge, and practice behavior of 6-12-year-old children.

Methods

Hand search and electronic search based on the keywords on school dental health education in seven search engines till 2017 identified 7434 articles. Trials involving school-based dental health education with a minimum follow-up period of 6 months were screened. Risk of bias assessment was done independently by two authors.

Results

Among the 18 articles which fulfilled the eligibility criteria, six were randomized controlled trials (RCTs) and 12 were non-RCTs. Quality assessment showed that 12 trials had a low risk of bias. Oral health-related knowledge improved in children. Oral health-related practice behaviors such as frequency and duration of brushing improved. Use of fluoridated toothpaste was increased. Plaque scores and gingival bleeding scores reduced.

Conclusion

School dental health education had a positive impact on the oral health status, knowledge, and practice behavior of children. There is a definite need for high-quality RCTs analyzing the effectiveness of school dental health education on specific oral health outcomes.

Evaluation of the Efficacy of Visual, Tactile Method, Caries Detector Dye, and Laser Fluorescence in Removal of Dental Caries and Confirmation by Culture and Polymerase Chain Reaction: An In Vivo Study

Aim

To determine the degree of association between visual and tactile methods of caries removal compared with caries detector dye and laser fluorescence device (DIAGNOdent), which detects the degree of demineralization; to determine the presence of Streptococcus mutans via culture and polymerase chain reaction (PCR) techniques; and to find a suitable method for caries removal.

Materials and Methods

A total of 75 patients were divided into three groups: visual and tactile (Group A), visual and tactile with caries detector dye (Group B), and visual and tactile with caries detector dye along with laser florescence readings (Group C). Caries removal was carried out using visual and tactile methods, caries detector dye, and laser fluorescence, and the samples obtained were subjected to culture and PCR. The data obtained were statistically analyzed using Pearson's chi-square test, analysis of variance (ANOVA), and Tukey's post hoc test.

Results

Visual and tactile along with caries detector dye and laser florescence (Group C) is the most efficient method for caries removal.

Conclusion

Caries detector dye along with visual, tactile examination and laser fluorescence is a valuable and superior tool for clinicians that aids in better caries removal and can prevent the overzealous removal of tooth structure.

Comparison of penetrating depth of chlorhexidine and chitosan into dentinal tubules with and without the effect of ultrasonic irrigation

Background:

Long term success of root canal treatment depends on complete removal of micro-organisms and their by-products. This can be effectively achieved by the ability of the irrigant to penetrate into the dentinal tubules, which is limited in the conventional mechanical debridement of the root canal system. Irrigant activation technique aids in movement of irrigants into the dentinal tubules.

Aim:

To compare the depth of penetration of root canal irrigants into the dentinal tubules with and without ultrasonics using light microscope.

Materials and Methods:

Forty noncarious mandibular premolars were used, all the tooth specimens were inoculated with an ATCC 29212 strain of E.faecalis and incubated under nutrient rich aerobic conditions at 37°C. Teeth were sectioned below the cementoenamel junction to obtain a standard length of 8 mm and instrumented with K-files, irrigated with 5.25% sodium hypochlorite and a final rinse of 17% EDTA. Teeth were divided into four groups of ten each. Group IA was irrigated with 2% Chlorhexidine (CHX) and agitated ultrasonically, Group IB was irrigated with 2% Chlorhexidine, Group IC was irrigated with 2% Chitosan and ultrasonically agitated, Group ID was irrigated with 2 % Chitosan. The tooth specimens were sectioned and subjected to gram staining and viewed under 100X oil immersion microscope. A micrometer grid was attached to the eyepiece to enable measurement of the depth of penetration of the irrigants. Group IA (2% Chlorhexidine with ultrasonic agitation) showed better penetration into the dentinal tubules as compared to Groups IB, IC, ID.

Results:

Irrigation with 2% Chlorhexidine with ultrasonic agitation had depth of penetration into the dentinal tubules upto 2350 μm. 2% Chlorhexidine without ultrasonic agitation penetrated upto 1800 μm. Chitosan with ultrasonic agitation penetrated upto1250 μm and Chitosan without ultrasonic agitation penetrated upto 44.80 μm.

Conclusion:

2% Chlorexidine as irrigant with ultrasonic agitation was found to have maximum depth of penetration into the dentinal tubules when compared with Chitosan.

Evaluation of bioflavonoids on the immediate and delayed microtensile bond strength of self-etch and total-etch adhesive systems to sound dentin

Aim

This study aims to evaluate the effect of two bioflavonoids (epigallocatechin-3-gallate [EGCG] and catechin) and a protein inhibitor (chlorhexidine [CHX]) on the immediate and delayed microtensile bond strength of self-etch and total-etch adhesive systems to sound dentin.

Materials and Methods

The occlusal surfaces of 96 mandibular human third molar teeth specimens were ground after removal of the excess tissues, to expose the middle dentin. The dentin specimens were randomly allocated into four groups, each consisting of 24 teeth (n = 24) according to the application of the enzyme inhibitor. The adhesive system used in this study was Adper easy bond, a self-etch adhesive system, and Adper Single Bond 2, a total-etch adhesive system. Microtensile bond strength testing was conducted using thermocycler 2000, Heto-Holten A/S.

Results

All the three enzyme inhibitors increase the bond strength values of the resin-dentin interphase when used during dentin bonding. The EGCG enzyme inhibitor has shown the highest immediate bond strength to dentin when used with both the adhesive systems.

Objective and subjective parameters of oral health in South Indian children: A cross-sectional study

Background

Oral health of schoolchildren is a strong predictor of their overall well-being. This study was planned to assess and compare the objective and subjective parameters of oral health of South Indian school children.

Methodology

Three hundred and sixty school children participated in this cross-sectional study. Their oral hygiene status, dental caries status, and treatment needs were assessed. Two questionnaires were filled by these children, to assess their oral health-related quality of life (OHRQoL) and their knowledge on oral health. Their academic scores were collected from the schools. Statistical analysis was done using Kruskal-Wallis ANOVA test and Spearman correlation test appropriately.

Results

Children with no caries had better OHRQoL (P = 0.02). There was a negative correlation between dental caries status and OHRQoL score (P = 0.003) and dental caries treatment needs and OHRQoL score (P = 0.01). There was a positive correlation between knowledge on oral health and OHRQoL score (P = 0.02).

Conclusion

Children with no caries had a better OHRQoL when compared to children with caries. Children with caries had more treatment needs, poor oral hygiene, low quality of life, and performed lesser in academics. However, they had adequate knowledge on oral health. Hence, both objective and subjective parameters of oral health should be given importance while treating children.

Comparison of Oral Health Status and Knowledge on Oral Health in Two Age Groups of Schoolchildren: A Cross-sectional Study

INTRODUCTION

Oral health plays a pivotal role in the overall wellbeing of children. As children grow, there is a variation in their oral health status due to the changing trends and lifestyle.

AIM

To evaluate and compare the factors related to oral health status in two age groups of school going children.

MATERIALS AND METHODS

A total of 582 children aged 8 to 11 years from 3 schools were included. Based on their school grade, they were grouped as younger (third grade) and older (fifth grade) children. Their dental caries status, caries treatment needs, oral hygiene status were assessed. A questionnaire was given to them to assess their knowledge on oral health.

RESULTS

Both third and fifth grade children had similar caries status. The caries treatment needs was significantly higher (p = 0.02) in fifth grade children of school III. The oral hygiene status was significantly better (p = 0.004) in fifth grade children of school I and third grade children (p < 0.001) of school III. Fifth grade children were found to have more knowledge on oral health and it was statistically significant in school II (p = 0.001). In school III, as caries status increased, the oral hygiene index score significantly increased (p = 0.001).

CONCLUSION

Age did not have any influence on the oral health status of children. The older children had better knowledge on oral health, but the oral hygiene practices were not followed effectivelyHow to cite this article: Geethapriya PR, Asokan S, Kandaswamy D. Comparison of Oral Health Status and Knowledge on Oral Health in Two Age Groups of Schoolchildren: A Cross-sectional Study. Int J Clin Pediatr Dent 2017;10(4): 340-345.

Substantivity of hypochlorous acid-based disinfectant against biofilm formation in the dental unit waterlines

Objective:

The purpose of the study was to examine the substantivity of a new disinfectant against biofilm formation in the dental unit waterlines.

Materials and Methods:

Twenty dental units were selected for the study and divided into two groups: Group A (dental unit waterlines treated with the disinfectant) and Group B (untreated dental unit waterlines). Biofilm formation was monitored in both groups by removing the one dental unit waterline from each group for the period of 10 days. One inch of the dental unit waterline tube was cut at random site, and the inner lumen of the cut sections was analyzed using the scanning electron microscope (SEM) (TESCAN VEGA3 SBU).

Results:

On examination, SEM images showed that there was no slime layer or bacterial cells seen in cut section for the period of 7 days in the treated dental waterlines, which means that there is no evident of biofilm formation. In the untreated dental unit waterline cut section, slime layer was observed from day 1.

Conclusion:

Disinfectant solution was proved to be effective for 7 days against biofilm formation. This technique could be used as a valid method for disinfection of dental unit waterlines.

Flipped clinical training: a structured training method for undergraduates in complete denture prosthesis

PURPOSE

To design and implement flipped clinical training for undergraduate dental students in removable complete denture treatment and predict its effectiveness by comparing the assessment results of students trained by flipped and traditional methods.

METHODS

Flipped training was designed by shifting the learning from clinics to learning center (phase I) and by preserving the practice in clinics (phase II). In phase I, student-faculty interactive session was arranged to recap prior knowledge. This is followed by a display of audio synchronized video demonstration of the procedure in a repeatable way and subsequent display of possible errors that may occur in treatment with guidelines to overcome such errors. In phase II, live demonstration of the procedure was given. Students were asked to treat three patients under instructor's supervision. The summative assessment was conducted by applying the same checklist criterion and rubric scoring used for the traditional method. Assessment results of three batches of students trained by flipped method (study group) and three traditionally trained previous batches (control group) were taken for comparison by chi-square test.

RESULTS

The sum of traditionally trained three batch students who prepared acceptable dentures (score: 2 and 3) and unacceptable dentures (score: 1) was compared with the same of flipped trained three batch students revealed that the number of students who demonstrated competency by preparing acceptable dentures was higher for flipped training (χ²=30.996 with p<0.001).

CONCLUSION

The results reveal the supremacy of flipped training in enhancing students competency and hence recommended for training various clinical procedures.

Dental unit waterlines disinfection using hypochlorous acid-based disinfectant

Objective:

The purpose of the study was to investigate the efficacy of a new disinfectant to disinfect the dental unit waterlines.

Materials and Methods:

New dental unit waterlines were installed in 13 dental chairs, and biofilm was allowed to grow for 10 days. Disinfection treatment procedure was carried out in the 12 units, and one unit was left untreated. The dental unit waterlines were removed and analyzed using the scanning electron microscope (SEM) (TESCAN VEGA3 SBU).

Result:

On examination, SEM images showed that there was no slime layer or bacterial cells seen in any of the 12 cut sections obtained from the treated dental waterlines which mean that there was no evident of biofilm formation. Untreated dental unit waterlines showed a microbial colonization with continuous filamentous organic matrix. There was significant biofilm formation in the control tube relative to the samples.

Conclusion:

The tested disinfectant was found to be effective in the removal of biofilm from the dental unit waterlines.

Health camps in schools and content analysis of the school textbooks: A cross-sectional study in Tamil Nadu

BACKGROUND

School textbooks have been considered as an effective platform for promoting oral health. The information on oral health in the Indian school textbooks has not been evaluated.

AIM

The aim of this study was to evaluate the contents of school textbooks on oral health and to quantitatively analyze the school health camps and guest lectures/demonstrations conducted in the schools of three districts in Tamil Nadu.

METHODOLOGY

Twenty schools which participated in the study followed the Central Board of Secondary Education, matriculation, or the state board syllabus. A questionnaire was designed to collect information about the medical camps, dental camps, guest lectures, and demonstrations conducted in the last academic year from the schools. The questionnaires were distributed among the school teachers of grades I-V. They were asked to provide photocopies of the topics on oral health which were included in the syllabus. Content analysis of the information on oral health-related topics in the school textbooks was done. Descriptive statistics of the details of the camps and lectures was done using Pearson's Chi-square test (SPSS version 17) (SPSS Inc. Chicago, Illinois, USA).

RESULTS

There was no significant difference in the number of medical camps (P = 0.445), dental camps (P = 0.055), and guest lectures (P = 0.069) organized among the three boards of schools. Basic information on the parts and type of teeth, tooth decay, and brushing were present in the textbooks of all three boards of schools.

CONCLUSION

The school textbooks of all the three boards contained basic and adequate information on oral health. Periodic revisions of the content and quality of information in the school textbooks are essential. To make the information sticky for long-term, reinforcements in the form of school health education is needed.

Evaluation of the Antibacterial Efficacy of Azadirachta Indica, Commiphora Myrrha, Glycyrrhiza Glabra Against Enterococcus Faecalis using Real Time PCR

AIM

To compare the antibacterial efficacy of Azadirachta indica (Neem), Commiphora myrrha (Myrrh), Glycyrrhiza glabra (Liquorice) with 2% Chlorhexidine (CHX) against E. faecalis by using Real Time PCR.

MATERIALS AND METHODS

A total of fifty teeth specimens (n=50) were inoculated with E. faecalis for 21 days. Specimens were divided into five groups (Group 1: Myrrh, Group 2: Neem, Group 3: Liquorice, Group 4: 2% CHX and Group 5: Saline (negative control)). The intracanal medicaments were packed inside the tooth. After 5 days, the remaining microbial load was determined by using real time PCR.

RESULTS

Threshold cycle (Ct) values of Myrrh extract, Neem extract, Liquorice Extract, 2% CHX and saline were found to be 30.94, 23.85, 21.38, 30.93 and 17.8 respectively.

CONCLUSION

Myrrh extract showed inhibition of E.faecalis equal to that of 2% CHX followed by Neem, Liquorice and Saline.

Mechanical behavior of deep cryogenically treated martensitic shape memory nickel-titanium rotary endodontic instruments

OBJECTIVES

The aim of this study was to investigate the role of deep cryogenic treatment (DCT) on the cyclic fatigue resistance and cutting efficiency of martensitic shape memory (SM) nickel-titanium (NiTi) rotary endodontic instruments.

MATERIALS AND METHODS

Seventy-five HyFlex(®) CM instruments were randomly divided into three groups of 25 each and subjected to different DCT (-185° C) conditions based on soaking time: DCT 24 group: 24 h, DCT 6 group: 6 h, and control group. Each group was randomly subdivided for evaluation of cyclic fatigue resistance in custom-made artificial canals (n = 15) and cutting efficiency in plexiglass simulators (n = 10). The cyclic fatigue resistance was measured by calculating the number of cycles to failure (NCF) and cutting efficiency was measured using the loss of weight method.

RESULTS

Increase in NCF of instruments in DCT 24 group was highly significant (P < 0.01; Tukey's honest significant difference). There was no difference in weight loss of plexiglass simulators in all the groups (P > 0.05; one-way analysis of variance). In conclusion, deep dry cryogenic treatment with 24 h soaking time significantly increases the cyclic fatigue resistance without affecting the cutting efficiency of SM NiTi endodontic instruments.

MATERIALS AND METHODS

Seventy-five HyFlex(®) CM instruments were randomly divided into three groups of 25 each and subjected to different DCT (-185° C) conditions based on soaking time: DCT 24 group: 24 h, DCT 6 group: 6 h, and control group. Each group was randomly subdivided for evaluation of cyclic fatigue resistance in custom-made artificial canals (n = 15) and cutting efficiency in plexiglass simulators (n = 10). The cyclic fatigue resistance was measured by calculating the number of cycles to failure (NCF) and cutting efficiency was measured using the loss of weight method.

RESULTS

Increase in NCF of instruments in DCT 24 group was highly significant (P < 0.01; Tukey's honest significant difference). There was no difference in weight loss of plexiglass simulators in all the groups (P > 0.05; one-way analysis of variance). In conclusion, deep dry cryogenic treatment with 24 h soaking time significantly increases the cyclic fatigue resistance without affecting the cutting efficiency of SM NiTi endodontic instruments.

Effect of dry cryogenic treatment on Vickers hardness and wear resistance of new martensitic shape memory nickel-titanium alloy

OBJECTIVES

The aim of this study is to investigate the role of dry cryogenic treatment (CT) temperature and time on the Vickers hardness and wear resistance of new martensitic shape memory (SM) nickel-titanium (NiTi) alloy. The null hypothesis tested was that there is no difference in Vickers hardness and wear resistance between SM NiTi alloys following CT under two soaking temperatures and times.

MATERIALS AND METHODS

The composition and the phase transformation behavior of the alloy were examined by X-ray energy dispersive spectroscopy and differential scanning calorimetry, respectively. Fifteen cylindrical specimens and 50 sheet specimens were subjected to different CT conditions: Deep cryogenic treatment (DCT) 24 group: -185°C, 24 h; DCT six group: -185°C, 6 h; shallow cryogenic treatment (SCT) 24 group: -80°C, 24 h; SCT six group: -80°C, 6 h; and control group. Wear resistance was assessed from weight loss before and after reciprocatory wet sliding wear.

RESULTS

The as-received SM NiTi alloy contained 50.8 wt% nickel and possessed austenite finish temperature (Af) of 45.76°C. Reduction in Vickers hardness of specimens in DCT 24 group was highly significant (P < 0.01; Tukey's honest significant difference [HSD]). The weight loss was significantly higher in DCT 24 group (P < 0.05; Tukey's HSD).

CONCLUSION

Deep dry CT with 24 h soaking period significantly reduces the hardness and wear resistance of SM NiTi alloy.

Anatomic symmetry of root and root canal morphology of posterior teeth in Indian subpopulation using cone beam computed tomography: A retrospective study

OBJECTIVE

To investigate the anatomic symmetry of maxillary and mandibular posteriors in Indian subpopulation using cone beam computed tomography (CBCT).

MATERIALS AND METHODS

CBCT images of 246 patients that had at least one noncarious, posterior tooth free of restorations in each quadrant were enrolled for retrospective analysis. A total of 3015 teeth (811 maxillary premolars, 845 mandibular premolars, 738 maxillary molars, and 621 mandibular molars) were analyzed for number of roots and root canals, canal morphology and anatomic symmetry, and concurrent types between the maxilla and mandible.

RESULTS

There was no difference in the percentage of symmetry for maxillary first (81.5%) and second (81.5%) premolars. Mandibular second premolars (98.3%) exhibited greater symmetry than mandibular first premolars (96.1%). First molars (77.5% and 82.1%) showed greater symmetry than second molars (70.8% and 78.6%), in both maxillary and mandibular arches, respectively. The most common anatomy observed were: maxillary first premolars - 2 roots with 2 canals, maxillary second premolars - 1 root with 2 canals, mandibular first and second premolars - 1 root with 1 canal, maxillary first and second molars - 3 roots with 4 canals, and mandibular first and second molars - 2 roots with 3 canals. When compared with any other teeth, maximum asymmetry was observed in maxillary second molar (29.2%).

CONCLUSION

The percentage of symmetry observed in the present study varied from 70% to 98% with least percentage of symmetry in maxillary second molars. These data should alert the clinicians while treating homonymous teeth of the same patient.

β-lactam substituted polycyclic fused pyrrolidine/pyrrolizidine derivatives eradicate C. albicans in an ex vivo human dentinal tubule model by inhibiting sterol 14-α demethylase and cAMP pathway

BACKGROUND

Further quest for new anti-fungal compounds with proven mechanisms of action arises due to resistance and dose limiting toxicity of existing agents. Among the human fungal pathogens C. albicans predominate by infecting several sites in the body and in particular oral cavity and root canals of human tooth.

METHODS

In the present study, we screened a library of β-lactam substituted polycyclic fused pyrrolidine/pyrrolizidine compounds against Candida sp. Detailed molecular studies were carried out with the active compound 3 on C. albicans. Morphological damage and antibiofilm activity of compound 3 on C. albicans was studied using scanning electron microscopy (SEM). Biochemical evidence for membrane damage was studied using flow cytometry. In silico docking studies were carried out to elucidate the mechanism of action of compound 3. Further, the antifungal activity of compound 3 was evaluated in an ex vivo dentinal tubule infection model.

RESULTS

Screening data showed that several new compounds were active against Candida sp. Among them, Compound 3 was most potent and exerted time kill effect at 4h, post antifungal effect up to 6h. When used in combination with fluconazole or nystatin, compound 3 revealed an minimum inhibitory concentration (MIC) decrease by 4 fold for both drugs used. In-depth molecular studies with compound 3 on C. albicans showed that this compound inhibited yeast to hyphae (Y-H) conversion and this involved the cAMP pathway. Further, SEM images of C. albicans showed that compound 3 caused membrane damage and inhibited biofilm formation. Biochemical evidence for membrane damage was confirmed by increased propidium iodide (PI) uptake in flow cytometry. Further, in silico studies revealed that compound 3 docks with the active site of the key enzyme 14-α-demethylase and this might inhibit ergosterol synthesis. In support of this, ergosterol levels were found to be decreased by 32 fold in compound 3 treated samples as analyzed by high performance liquid chromatography (HPLC). Further, the antifungal activity of compound 3 was evaluated in an ex vivo dentinal tubule infection model, which mimics human tooth root canal infection. Confocal laser scanning microscopy studies showed 83% eradication of C. albicans and a 6 log reduction in colony forming unit (CFU) after 24h treatment in the infected tooth samples in this model.

CONCLUSION

Compound 3 was found to be very effective in eradicating C. albicans by inhibiting cAMP pathway and ergosterol biosynthesis.

GENERAL SIGNIFICANCE

The results of this study can pave the way for developing new antifungal agents with well deciphered mechanisms of action and can be a promising antifungal agent or medicament against root canal infection.

Integrated case scripts to enhance diagnostic competency

Background

The overwhelmingly high burden of disease and disorder especially in developing countries requires oral physicians to provide optimal dental treatment without complicating individuals’ general health. The opportunity for learners to extract the multiple aspects of a systemic condition and to relate them with the presenting complaint in order to devise an appropriate dental treatment plan is limited by time in chair- side teaching. To overcome the necessity of exposing students to real patients with varying degrees of underlying disease, those in medical and nursing education unanimously employ imaginary scenarios similar to real cases. However, such clinical scripts are seldom practiced in dental education, and the prospect of structured integration is almost never addressed.

Objectives

To evaluate the effectiveness of applying systematic and integrated case-based discussion in dental education in terms of enhancing five essential skills to novice Indian dental students.

Methods

A mixed- methods study was carried out with thirty graduating third-year students in 5 focus groups. The integrated case-based focused group training occurred in 6 weeks and lasted approximately 90 minutes per discussion. Ten case scripts of hypothetical situations were discussed and five integrated modules were organized as a part of this program. Revised Bloom’s taxonomy was adopted to achieve the expected level of competency.

Results

Students performance following integrated case-based discussions was improved and their acceptance to this practice is positive.

Conclusions

The present study supports the need for course specific, basic science integrated seminars with concurrent case scripts discussion to enhance students’ competencies.

Key words:Case scripts, Revised Bloom’s taxonomy, chair-side teaching, integrated teaching.

A Confocal Microscopic Evaluation of the Dehydration Effect on Conventional, Resin Reinforced Powder/Liquid and Paste to Paste Glass Ionomer Luting Cements

BACKGROUND

The purpose of this study was to evaluate the effect of dehydration of resin-modified glass ionomer powder/liquid system, resin-modified glass ionomer paste/paste luting cements in three different quantities and to compare them with a conventional glass ionomer luting cement using confocal laser scanning microscope.

MATERIALS AND METHODS

A conventional glass ionomer (Group I), a resin modified powder/liquid system (Group II), and a resin-modified paste/paste system (Group III) were selected for the study. In Group III, there were three subgroups based on the quantity of material dispensed. 50 premolar teeth were selected and randomly divided among the groups with 10 samples in each. The teeth were ground flat to expose a flat occlusal dentin. A device was made to standardize the thickness of cement placed on the teeth. The teeth were stored in distilled water for 24 h and then longitudinally sectioned to examine the tooth dentin interface under a confocal microscope. The specimens were allowed to dehydrate under the microscope for different time intervals. The width of the crack after dehydration near the dentinal interface was measured at definite intervals in all the groups and analyzed statistically using Student's t-test.

RESULTS

Conventional glass ionomer cement showed the maximum width of the crack followed by resin modified paste/paste system during the dehydration period. Resin modified powder/liquid system did not show cohesive failure.

CONCLUSIONS

Conventional glass ionomer luting cement is more susceptible to cohesive failure when subjected to dehydration compared to resin-modified glass ionomer paste/paste luting cement. Among the luting cements, resin-modified glass ionomer powder/liquid system showed the best results when subjected to dehydration.

Microstructure of cryogenically treated martensitic shape memory nickel-titanium alloy

Context:

Recent introduction of shape memory (SM) nickel-titanium (NiTi) alloy into endodontics is a major breakthrough. Although the flexibility of these instruments was enhanced, fracture of rotary endodontic instruments during instrumentation is an important challenge for the operator. Implementation of supplementary manufacturing methods that would improve the fatigue life of the instrument is desirable.

Aim:

The purpose of this study was to investigate the role of dry cryogenic treatment (CT) conditions on the microstructure of martensitic SM NiTi alloy.

Materials and Methods:

Experiments were conducted on Ni-51 wt% Ti-49 wt% SM alloy. Five cylindrical specimens and five sheet specimens were subjected to different CT conditions: Deep CT (DCT) 24 group: −185°C; 24 h, DCT 6 group: −185°C; 6 h, shallow CT (SCT) 24 group: −80°C, 24 h, SCT 6 group: −80°C, 6 h and control group. Microstructure of surface was observed on cylindrical specimens with an optical microscope and scanning electron microscope at different magnifications. Subsurface structure was analyzed on sheet specimens using X-ray diffraction (XRD).

Results:

Microstructures of all SM NiTi specimens had equiaxed grains (approximately 25 μm) with well-defined boundaries and precipitates. XRD patterns of cryogenically treated specimens revealed accentuation of austenite and martensite peaks. The volume of martensite and its crystallite size was relatively more in DCT 24 specimen.

Conclusions:

DCT with 24 h soaking period increases the martensite content of the SM NiTi alloy without altering the grain size.

A comparative evaluation of the canal centering ability of three rotary nickel-titanium retreatment systems in the mesio-buccal canals of mandibular first molars using computed tomography

Background:

During endodontic retreatment, relative difficulty exists in removing the filling material and maintaining the canal anatomy. Usage of nickel-titanium (NiTi) rotary retreatment instruments is widely accepted, but there is a lack of adequate literature evidence about their canal centering ability.

Aim:

To compare the canal centering ability of rotary NiTi retreatment systems.

Materials and Methods:

Mandibular first molars with mesiobuccal canals with canal access angle of 20-40° were used. Canals prepared until ISO 25, 0.06 taper. Obturated with three different techniques lateral compaction, Thermafil, and Resilon/Epiphany. Retreatment was carried using three different systems ProTaper retreatment, Mtwo R and REndo. Specimens were subjected to computed tomography analysis at coronal, middle, and apical third of the root canal preobturation and postretreatment procedure.

Statistical Analysis Used:

One-way ANOVA and post-hoc Tukey test.

Results:

No statistically significant difference with three retreatment systems. Variation existed among all the subgroups at the coronal, middle, and apical third of the root canal.

Conclusion:

All retreatment systems with three obturation techniques showed eccentricity within acceptable limits. REndo, MtwoR showed better canal centering and ProTaper retreatment system showed tendency for eccentric canal preparation, especially in apical third.

Endodontic management of a mandibular second molar with radix entomolaris: a case report

The presence of radix entomolaris (RE) in a mandibular first molar is a common occurrence in certain ethnic groups, but the presence of RE in a mandibular second molar is a rare occurrence. In the present case, RE was identified from preoperative radiographs and confirmed using cone-beam computed tomography (CBCT). The access cavity was modified to locate the RE. Cleaning and shaping were performed with nickel-titanium rotary instruments. Obturation was completed with gutta-percha cones using AH Plus (Dentsply Detrey GmbH) as sealer. From the CBCT axial images, the RE was determined to have a Type III curvature by the De Moor classification, Type B separate RE by the Carlsen and Alexandersen classification, and radiographically, a Type i image by the Wang classification. The presence of RE in the mandibular second molar makes it essential to anticipate and treat the distolingual root canal. This case report highlights the usefulness of CBCT for assessing RE in the mandibular second molar, which can help the clinician in making a confirmatory diagnosis and assessing the morphology of the root canal.

A comparative assessment of fracture resistance of endodontically treated and re-treated teeth: An in vitro study

Aim:

To compare and assess the fracture resistance of endodontically treated teeth with those that have been subjected to endodontic retreatment.

Materials and Methods:

30 extracted mandibular premolars were decoronated at cementoenamel junction and randomly divided into 2 groups. In Group I endodontic treatment was performed with ProTaper rotary system till size F2 and obturated. In Group II, cleaning and shaping was done and teeth were subjected to Spiral CT to assess the remaining dentin thickness and obturated. Later retreatment was done using Protaper Universal Retreatment system and final shaping was performed till size F3. Remaining dentin thickness was again assessed using Spiral CT and then obturated. All the specimens were subjected to fracture resistance using universal testing machine. The results were statistically analyzed using Independent Samples t-test for analysis of remaining dentin thickness using SCT within Group II and Paired Samples t-test was used for assessment of fracture resistance between Group I and II (P < 0.05).

Results:

In Group II, the intra group comparison of the remaining dentin thickness in the coronal third reveals statistical significance, with a significant difference noted in the apical third. Results of the fracture resistance reveal a statistically significant difference (P < 0.05) between Groups I and II with the mean fracture resistance of Group I being higher than Group II.

Conclusion:

Endodontically retreated teeth have shown significantly decreased resistance to fracture and this has a positive correlation to the increased loss of root dentin during the retreatment procedures

Remineralisation of occlusal white spot lesion with a combination of 10% CPP-ACP and 0.2% sodium fluoride evaluated using Diagnodent: a pilot study

PURPOSE

To evaluate the efficacy of 10% casein phosphopeptide amorphous calcium phosphate complex (CPP-AC P) used alone or with fluoride as compared to fluoride mouthrinse for the remineralisation of occlusal white spot lesions in an in vivo pilot study.

MATERIALS AND METHODS

Forty-five subjects with occlusal white spot lesions (WSL) determined by visual examination and confirmed with Diagnodent were randomly divided into 3 groups: group 1: 10% CPP-AC P + 0.2% NaF; group 2: 10% CPPAC P; group 3: 0.5% NaF mouthrinse for 30 days. The pre-treatment and post-intervention Diagnodent values were tabulated and subjected to statistical analysis.

RESULTS

Among the groups, the remineralising potential of 10% CPP-AC P + 0.2% NaF (group 1) and 10% CPP-AC P (group 2) were similar, however, both groups were superior to 0.5% NaF mouthrinse (group 3).

CONCLUSIONS

The CCP-AC P technique is highly beneficial for the remineralisation of non-cavitated occlusal white spot lesions when compared to 0.5% NaF mouthrinse.

Influence of various herbal irrigants as a final rinse on the adherence of Enterococcus faecalis by fluorescence confocal laser scanning microscope

Aim:

The aim of this study was to assess the antibacterial efficacy of three different herbal irrigants against Enterococcus faecalis.

Materials and Methods:

Single rooted teeth were extracted due to orthodontic and periodontal reasons. The teeth were then inoculated with E. faecalis. The teeth were randomly divided into three experimental groups and two control groups of six samples each. Group 1 specimens were treated with 5.2% sodium hypochlorite (NaOCL) for 30 min followed by 5 mmol/L Ethylenediaminetetraacetic acid (EDTA) for 5 min and saline as final irrigant. Group 2 specimens were treated with and 5.2% NaOCl for 30 min as final irrigant. Group 3 were treated with Morinda citrifolia (MC) for 30 min as final irrigant. Group 4 were treated with Azadiracta indica (AI) as final irrigant. Group 5 were treated with green tea (GT) for 30 min as final irrigant. The dentin specimens were carefully spread onto a microscope slide and stained with BacLight and examined in a confocal laser scanning microscope set to monitor fluorescein isothiocyanate and propidium iodide. A total of nine fields were examined for each treatment and the bacteria presented were counted.

Statistical Analysis:

Using the one-way ANOVA with multiple comparison, significantly less bacteria were found adhering to the samples treated with Neem followed by NaOCL, GT, MC, Saline.

Results:

AI treatment produced the maximum reduction in adherence of E. faecalis to dentin (9.30%) followed by NaOCl (12.50%), GT (27.30%), MC (44.20%) and saline (86.70%).

Conclusion:

Neem is effective in preventing adhesion of E. faecalis to dentin.

Dentinal tubule disinfection with 2% chlorhexidine, garlic extract, and calcium hydroxide against Enterococcus faecalis by using real-time polymerase chain reaction: In vitro study

AIM

To compare the efficacy of garlic extract with 2% chlorhexidine (CHX) and calcium hydroxide Ca(OH)2 in disinfection of dentinal tubules contaminated with Enterococcus faecalis by using real-time polymerase chain reaction (PCR).

MATERIALS AND METHODS

Agar diffusion test was done to evaluate the minimum inhibitory concentration of garlic extract against E. faecalis. Forty human extracted mandibular premolar teeth were selected for this study, access cavity was prepared and cleaning and shaping was done. Middle third of the root was cut using a rotary diamond disc. The teeth specimens were inoculated with E. faecalis for 21 days. Specimens were divided into four groups---Group 1: 2% CHX, Group 2: Garlic extract, Group 3: Ca(OH)2, and Group 4: Saline (negative control). The intracanal medicaments were packed inside the tooth specimens and incubated for 5 days. The dentinal chips were collected at 400 μm depth using a Gates-Glidden drill, following which DNA isolation was done. The specimens were analyzed using real-time PCR. The results were then statistically analyzed using one-way analysis of variance, followed by post hoc Tukey's honestly significant difference (HSD) multiple comparison of means.

RESULTS

Threshold cycle (Ct) values of 2% CHX was found to be 32.4, garlic extract to be 27.5, and Ca(OH)2 to be 25.6.

CONCLUSION

A total of 2% CHX showed the maximum efficacy against E. faecalis, followed by garlic extract and Ca(OH)2.

In vitro evaluation of five different herbal extracts as an antimicrobial endodontic irrigant using real time quantitative polymerase chain reaction

Context:

Sodium hypochlorite is the most commonly used irrigant but it has disadvantage like high cytotoxicity. So there is a need to find an alternative to 5.25% Sodium hypochlorite against microorganism Enterococcus faecalis and Candida albicans. Literature has shown that these 5 extracts namely Terminalia chebula, Myristica frangrans, Aloe barbadensis, Curcuma longa and Azadaricta indica has good properties which can be used as a potential endodontic irrigant.

Aims:

To evaluate the antimicrobial efficacy of various herbal extracts namely Curcuma longa (CL), Azadiracta indica (AI), Aloe barbadensis (AV), Myristica fragrans (MF) and Terminalia chebula (TC) as endodontic irrigant against Enterococcus faecalis and Candida albicans using real-time quantitative polymerase chain reaction (qPCR).

Materials and Methods:

Eighty-four teeth were extracted and suspended with Enterococcus faecalis and Candida albicans. A preliminary study was first performed to determine the minimum inhibitory concentration of extracts. The irrigating groups were divided into five herbal groups and 2 control groups. After irrigating the teeth the remaining microbial load was determined using qPCR.

Statistical Analysis Used:

Statistical analysis was performed using Oneway Anova/Kruskal-Wallis test with post-hoc Tukey's HSD and was statistically significant (P < 0.05).

Results:

It was shown that Neem was highly efficient to 5.25% NaOCl in reducing Enterococcus faecalis and Candida albicans within the root canals when compared with other extracts.

Conclusions:

Neem leaf extract has a significant antimicrobial efficacy against Enterococcus faecalis and Candida albicans compared to 5.25% sodium hypochlorite.

Evaluation of the sealing ability of two sealers after using chlorhexidine as a final irrigant: An in vitro study

Aims and Objectives:

The aim of this study was to evaluate the effect of the precipitate formed by using sodium hypochlorite and chlorhexidine as a root canal irrigant on the sealing ability of different root canal sealers, using a push-out bond strength test.

Materials and Methods:

Twenty single rooted premolars were used for this study. The teeth were divided into two groups (Groups I and II) of ten teeth each, according to the obturation done with AH Plus with GuttaPercha and Resilon with epiphany, respectively. The groups were in turn divided into two subgroups of five teeth each (Subgroups A and B) according to the irrigation protocol, and were evaluated using a micro push-out bond strength, with the help of a universal testing machine. Statistical analysis was done using the paired t test.

Results:

The mean value of the AH Plus GuttaPercha group with precipitate formation (17.66 ± 0.56) showed the highest mean value for the bond strength, which was statistically higher (P < 0.05) than the rest of the groups. In the Resilon Epiphany group, the samples with precipitate formation showed (13.28 ± 1.35) the least bond strength, which was statistically lower than all the groups, except the Resilon samples without precipitate (13.99 ± 0.48).

Conclusion:

The precipitate formed by a combination of sodium hypochlorite and chlorhexidine tends to affect the bond strength of the sealers used for obturation.

Molecular identification of an Enterococcus faecalis endocarditis antigen efaA in root canals of therapy-resistant endodontic infections

Introduction:

Enterococcus faecalis has long been implicated in persistent root canal infections and therapy-resistant endodontic infections. It has also been associated with bacteremia, that is, infective endocarditis arising from certain invasive dental procedures. E. faecalis endocarditis antigen (efaA) has been identified as one of the principal virulence factors associated with infective endocarditis.

Aim:

To detect the presence of putative E. faecalis virulence factor, efaA in root canals of therapy-resistant endodontic infections using polymerase chain reaction (PCR) amplification.

Materials and Methods:

Samples were obtained from 32 patients (20–70 years) undergoing endodontic retreatment, which were incubated in prereduced thioglycollate broth and subcultured onto ethyl violet azide broth (EVA; selective medium for E. faecalis). Deoxyribonucleic acid (DNA) was extracted from the samples and analyzed for the endocarditis virulence factor efaA using PCR.

Results:

Among the positive E. faecalis samples, efaA gene was identified in 11 out of 15 samples.

Conclusion:

Our findings indicate that efaA, a potent E. faecalis virulence gene can be found in E. faecalis strains detected in root canals of therapy-resistant endodontic infections similar to reports for ‘medical’ strains.

Shear bond strength evaluation of resin composite bonded to glass-ionomer cement using self-etching bonding agents with different pH: In vitro study

Aim:

To evaluate the bonding ability of composite to unset glass-ionomer cement (GIC) using different self-etching bonding systems.

Materials and Methods:

One hundred samples of composite bonded to unset GIC were prepared and were divided into four groups. In Group A, composite was bonded to unset GIC employing a strong (pH 1) self-etch primer was used. In Group B, intermediary strong (pH 1.4) self-etch primer was employed. In Group C and D, mild (pH 2) and (pH 2.2) self-etch primer was employed. Shear bond strength analysis was performed at a cross-head speed of 0.5 mm/min.

Results:

Statistical analysis performed with one way analysis of variance and Tukey's test showed that the bond strength of composite to unset GIC was significantly higher for the mild self-etch primer group. In addition, energy dispersive x-ray (EDX) analysis was used to determine the composition of various structural phases identified by FE-SEM along the GIC-bonding agent interfaces.

Conclusion:

Hence this present study concludes that clinically the use of mild self-etching bonding agent over unset GIC has improved bond strength compared to the use of strong and intermediate self-etching bonding agent.

Effect of ethylene diamine tetra-acetic acid, MTAD™, and HEBP as a final rinse on the microhardness of root dentin

CONTEXT

Evaluation of microhardness of root dentin provides indirect information on the change in mineral content of root dentin thereby providing useful information on the bonding quality of resin-based root canal sealers.

AIM

This study evaluated the effect of 17% EDTA, MTAD, and 18% HEBP solutions on the microhardness of human root canal dentin using the Vickers microhardness test.

MATERIALS AND METHODS

Forty human single-rooted teeth were decoronated at the cementoenamel junction and sectioned longitudinally into buccal and lingual segments. Eighty specimens were divided into four groups (n=20). Group I was treated with distilled water (control), groups II, III, and IV were treated with 1.3% NaOCl as a working solution for 20 minutes followed by 17% EDTA, MTAD, and 18% HEBP respectively. The surface hardness of the root dentin was determined in each specimen with a Vicker's hardness tester. The values were statistically analyzed using the one-way ANOVA and post hoc Tukey multiple comparison tests.

RESULTS

There was a statistical significant difference among all the groups (one-way ANOVA; P<0.001). Among the experimental groups, HEBP showed the highest dentin microhardness (53.74 MPa, P<0.001). Least microhardness was found with MTAD (42.85 MPa, P<0.001).

CONCLUSIONS

HEBP as a final rinse appears to be a promising irrigation protocol with less impact on the mineral content of root dentin.

Bactericidal effect of the 908 nm diode laser on Enterococcus faecalis in infected root canals

AIM

The aim of this study is to evaluate the bactericidal effect of 908 nm diode laser in conjunction with various irrigation regimes in disinfection of apical third of root dentin.

MATERIALS AND METHODS

Sixty prepared teeth with single canals were contaminated with Enterococcus faecalis. The specimens were divided into 6 groups (n = 10): Group 1 and 3 and 5 were subjected to chemo-mechanical preparation using 5.25% sodium hypochlorite (NaOCl), 17% Ethylenediaminetetraacetic acid (EDTA); 1.3% NaOCl, MTAD (mixture of doxycycline, citric acid and a detergent (Tween 80); and, 8.5% saline, respectively followed by 908 nm diode laser irradiation; Group 2 and 4, followed the same procedure as Group1 and 3, however without laser irradiation; and, Group 6, rinsed with saline solution (control). Dentin shavings from apical third were analyzed for the presence of E. faecalis using culture method and Polymerase Chain reaction (PCR).

RESULTS

One-way Analysis of variance showed statistically significant differences between the laser irradiated groups, non irradiated groups and the control group.

CONCLUSION

908 nm diode used in conjunction with conventional chemomechanical techniques demonstrated a significant elimination of E. faecalis in the apical third of root dentin.

Efficacy of F file compared to ultrasonic techniques using scanning electron microscopy

A study was undertaken to compare the debridement efficacy of the F file with ultrasonics. Thirty mandibular premolars were instrumented with the Protaper file series using a crown-down technique. All the canals were irrigated using 2 ml of 5.25% sodium hypochlorite and 2 ml of 17% EDTA for one minute, alternating each instrument. The teeth were then divided into three groups of 10 each. In Group I, a final flush with only 5.25% NaOCl concluded the preparation (control group). Group II underwent 5.25% NaOCl and ultrasonic irrigation for one minute. Group III, 5.25% NaOCl and F-file for 30 seconds. Smear layer and debris scores were examined under a scanning electron microscope. In a blind manner, two investigators scored the presence or absence of smear layer and debris. Significantly higher smear layer and debris scores were found at the apical level compared to the middle and coronal levels in all the three groups. In the end, the F file proved more beneficial in removing smear layer and debris than ultrasonics.

Disinfection of dentinal tubules with two different formulations of calcium hydroxide as compared to 2% chlorhexidine: As intracanal medicaments against Enterococcus faecalis and Candida albicans: An in vitro study

Aim:

To evaluate the disinfection of dentinal tubules using calcium hydroxide with propylene glycol and calcium hydroxide with iodoform in silicone oil, as compared to 2% chlorhexidine gel.

Materials and Methods:

The antimicrobial efficacy of the medicaments against E.faecalis and C.albicans were assessed in vitro, using a dentinal tubule model at depths of 200 μm and 400 μm in extracted single rooted teeth. Saline was taken as the negative control (Group I)

Results:

All three medicaments used in this study exerted antibacterial and antifungal activity. Group II (calcium hydroxide with propylene glycol) and Group IV (2% chlorhexidine gel) had the highest antimicrobial activity and the differences between their antibacterial activities were not statistically significant. Group III (calcium hydroxide with iodoform in silicone oil) and Group IV had the highest antifungal activity and the differences between their antifungal activities were not statistically significant. The inhibition of growth at 200 μm and 400 μm was uniform, with no statistical difference.

Conclusions:

Two percent chlorhexidine gel was effective against both E.faecalis and C.albicans. Calcium hydroxide with propylene glycol was the most effective intracanal medicament along with 2% chlorhexidine against E.faecalis, whereas, calcium hydroxide with iodoform in silicone oil was the most effective intracanal medicament along with 2% chlorhexidine against C.albicans.

Comparison of laterally condensed, vertically compacted thermoplasticized, cold free-flow GP obturations - A volumetric analysis using spiral CT

AIM/OBJECTIVE

To compare the laterally condensed gutta-percha, vertically compacted thermoplastized gutta-percha (E and Q Plus system) and cold free-flow gutta-percha (GuttaFlow). This is a volumetric analysis using spiral CT, an in vitro study.

MATERIALS AND METHODS

Access cavities were prepared in 60 single rooted anterior teeth; cleaning and shaping was done and obturated with three of the different techniques: group A: cold lateral; group B: vertically compacted thermoplasticized and group C: cold free-flow obturation techniques. Volume analysis was done using spiral computed tomography (CT). The percentage difference was calculated and statistically analyzed using one-way ANOVA and post hoc multiple comparison Tukey HSD tests.

RESULTS

There were statistical significant differences between group A (0.183cm(3)) and group B (0.136cm(3)); group A (0.183cm(3)) and group C (0.128cm(3)). But there was no statistical significance between group B (0.136cm(3)) and group C (0.128cm(3)).

CONCLUSION

Within the limitations of this in vitro study it can be concluded that cold free-flow obturation technique showed the highest volume of obturation, followed by the vertically condensed thermoplasticized technique. The least volume of obturation was observed in cold lateral condensation technique.

Effects of various final irrigants on the shear bond strength of resin-based sealer to dentin

Aim:

This study has been designed to evaluate the effect of strong (MTAD) or soft (1- hydroxyethylidene – 1, 1-bisphosphonate (HEBP) final irrigating solution on the shear bond strength of AH plus sealer to coronal dentin. 17% EDTA was used as the reference.

Materials and Methods:

Forty freshly extracted human maxillary first premolars were prepared using different irrigation protocols (n=10). All the test groups had 1.3% NaOCl as initial rinse and followed by specific final rinse for each group: G1 – distilled water(control), G2 – 17% EDTA, G3- 18% HEBP and G4 – MTAD. Sections of polyethylene tubes that are 3mm long were filled with freshly mixed sealer and placed on the dentin surfaces. The bonding between the sealer and dentine surface was evaluated using shear bond testing. The values were statistically evaluated using one-way ANOVA followed by Tukey's test.

Result:

Significant difference was found among the irrigating regimes. EDTA showed highest bond strength followed by HEBP and MTAD

Canal-centering ability: An endodontic challenge

During instrumentation of the root canal, it is important to develop a continuously tapered form and to maintain the original shape and position of the apical foramen. However, the presence of curvatures may cause difficulty in root canal instrumentation. The ability to keep the instruments centered is essential to provide a correct enlargement, without excessive weakening of the root structure. Several studies have shown that Ni-Ti instruments remain significantly more centered and demonstrated less canal transportation than stainless steel files. Considerable research has been undertaken to understand the several factors related to an instrument's canal-centering ability. In this article, we have discussed the influence of various parameters such as alloys used in the manufacture of instruments, instrument cross-section, taper, and have given tips on canal-centering ability.

Management of recently traumatized maxillary central incisors by partial pulpotomy using MTA: Case reports with two-year follow-up

In traumatized, young, permanent teeth, pulpotomy is classically undertaken to promote apexogenesis. The objective is to promote root development and apical closure. Once root end development and apical closure is achieved, the root canal treatment is completed. However, it has been suggested that mere pulp exposure does not cause pulpitis in the absence of bacteria. Recent studies have proposed that as long as a good seal is ensured, root canal treatment may not be necessary following pulpotomy. In this article we report two cases of traumatized, fully matured, maxillary permanent central incisors, which have been treated with mineral trioxide aggregate following partial pulpotomy, with a two-year follow-up.

Root canal irrigants

Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal. Of these three essential steps of root canal therapy, irrigation of the root canal is the most important determinant in the healing of the periapical tissues. The primary endodontic treatment goal must thus be to optimize root canal disinfection and to prevent reinfection. In this review of the literature, various irrigants and the interactions between irrigants are discussed. We performed a Medline search for English-language papers published untill July 2010. The keywords used were ‘root canal irrigants’ and ‘endodontic irrigants.’ The reference lists of each article were manually checked for additional articles of relevance.

Three-dimensional helical computed tomographic evaluation of three obturation techniques: In vitro study

AIM

The purpose of this study was to evaluate the adequacy of three obturation techniques namely lateral condensation, EQ Fil (backfill obturation) and thermafil (core carrier obturation) techniques using three-dimensional (3D) helical computed tomography (CT) by volume rendering method.

MATERIALS AND METHODS

Thirty freshly extracted teeth were randomly divided into three groups of 10 teeth each. Biomechanical preparation was done in all the teeth using rotary instruments. All three sets of teeth were placed in helical CT slice scanner and were imaged before obturation. The three sets were then obturated by following methods: Group I: lateral condensation, Group II: EQ Fil (backfill) and Group III: thermafil (core carrier obturation).Volume of the pulp chamber and gutta-percha after obturation were calculated using volume rendering technique and adequacy of the obturation techniques were calculated.

STATISTICAL ANALYSIS USED

One-way ANOVA and Multiple-Range Tukey Test by Tukey-HSD procedure

RESULTS

Mean change in lateral condensation (0.005±0.002) was significantly higher than that of thermafil obturation (0.002±0.001) [P<0.05].

CONCLUSIONS

Conventional lateral condensation technique showed maximal inadequacy of obturation and thermafil obturation technique showed the least inadequacy of obturation when the volume of the specimens were calculated and reconstructed.

CAD/CAM fabricated single-unit all-ceramic post-core-crown restoration

This case report explains about an innovative treatment strategy for the management of damaged anterior teeth with reduced incisal clearance by means of a single-unit all-ceramic post-core-crown zirconia ceramic restoration fabricated by Computer-aided designing and computer-aided manufacturing (CAD/CAM) technology. The reinforced zirconia ceramics allow fabrication of durable esthetic restorations in cases with high functional loading and the unification of the post, core, and crown in a single unit decreases the frequency of failure by creating a monobloc effect. In addition, the use of CAD/CAM technology for designing and fabricating ceramic restorations offers the option of expeditiously preparing these high-strength all-ceramic restorations.

Assessment of root canal morphology of mandibular first premolars in the Indian population using spiral computed tomography: an in vitro study

AIM

The aim of the study is to determine the root canal morphology of the mandibular first premolar teeth in an Indian population using spiral computed tomography (SCT).

MATERIALS AND METHODS

One hundred extracted mandibular first premolars were observed using Spiral Computed Tomography for the (i) Pattern of root canal (ii) Tooth length (iii) Position of the bifurcation of the canal (iv) Invagination of the root (v) Root thickness. The root canal morphology was classified based on Vertucci's classification.

RESULTS

Eighty percent of the teeth had a single canal, 11% of the teeth had two canals, and C-shaped canals were found in 2% of the teeth, in this study. The average length of the teeth was 21.6 mm. Fourteen percent of the teeth had mesial invagination of the root.

CONCLUSION

The Type I root canal morphology was the most common type of root canal system in the mandibular first premolars among the Indian population in this study.

Evaluation of the effect of MTAD in comparison with EDTA when employed as the final rinse on the shear bond strength of three endodontic sealers to dentine

The purpose of the study was to evaluate the effect of MTAD in comparison with EDTA as a final rinse on the shear bond strength of Kerr, Apexit and AH plus. Dentine surfaces of 135 extracted human non-carious maxillary premolars were divided into three groups (n = 45). Groups I and II were conditioned with 1.3% NaOCl for 20 min, followed by a final rinse of 17% EDTA for 1 min and MTAD for 5 min respectively. Group III was treated with distilled water. Each group was further divided into three subgroups (n = 15). Subgroup 1: Kerr, Subgroup 2: Apexit and Subgroup 3: AH plus. Three-millimetre-long sections of polyethylene tubes were filled with freshly mixed sealer and placed on the dentine surfaces. The bonding between the sealer and dentine surface was evaluated using shear bond testing. The values were statistically evaluated using one way anova followed by Tukey's test. Significant difference was found among the bond strength of the sealers and irrigating regimes. AH plus showed superior bond strength among the tested sealers, when EDTA was employed as the final rinse (P < 0.05). MTAD as a final rinse affected the bond strength of AH plus and Apexit, which were significantly lower than the control group.