Regenerative Endodontics: A Paradigm Shift in Clinical Endodontics.

Preserving the natural dentition in its normal form and function is one of the major goals of endodontic treatment. Re-establishing the lost vitality and development of root maturation in immature permanent teeth with pulp necrosis/apical periodontitis is quiet challenging clinically. The very basis of regenerative endodontics relies on the concept of tissue engineering using stem cells, biomimetic scaffold, and bioactive growth factors to regenerate the pulp tissue damaged by microbial infection, injury, or developmental defects. In clinical endodontics, this approach is referred to as a "paradigm shift." Even though repair instead of true regeneration is achieved with current protocols, it is hoped that further research in the area of stem-cell-based tissue engineering will allow for true regeneration and improved treatment outcomes. The aim of this review is to discuss about the various aspects of regenerative endodontics, current clinical protocols, and the future of pulp regeneration techniques.

Comparison of Antibacterial Effect of Calcium Hydroxide Combined With Chlorhexidine and Povidone-Iodine Against Enterococcus faecalis in Dentinal Tubules of Human Incisors: An In Vitro Comparative Study.

BACKGROUND AND OBJECTIVES: It has been found that the microorganism behind the failure of root-filled teeth is Enterococcus faecalis, which shows resistance to most of the intra-canal medicaments. Therefore, the purpose of this study was to evaluate the antibacterial efficacy of three intra-canal medications-calcium hydroxide with saline, combinations of calcium hydroxide with 2% chlorhexidine (CHX), and calcium hydroxide with 5% povidone-iodine-against E. faecalis in dentinal tubules of human incisors. MATERIALS AND METHODS: Forty permanent maxillary central incisors were made into standardized segments and infected with E. faecalis. They were treated with a paste made of calcium hydroxide and 2% CHX, calcium hydroxide and 5% povidone-iodine, and calcium hydroxide and saline for 1 week. Dentinal shavings collected from the canal were suspended in thioglycollate broth solution and spread on brain heart infusion agar. Colony-forming units (CFUs) were enumerated and the CFU per milligram of dentin was calculated. The pH of the medicaments used was measured with the help of pH meter. RESULTS: The results showed that the paste made from calcium hydroxide and 2% CHX was significantly more effective than that made from calcium hydroxide and povidone-iodine, and calcium hydroxide and saline. The addition of CHX or povidone-iodine did not affect the alkalinity of calcium hydroxide. CONCLUSION: This study concludes that Ca(OH)2 + 2% CHX are effective against E. faecalis. Combinations of calcium hydroxide and 5% povidone-iodine showed better antibacterial effect than calcium hydroxide and saline. Ca(OH)2 + saline was ineffective against E. faecalis.

Evaluation of the Impact of Acidic Drink on the Microhardness of Different Esthetic Restorative Materials: An In Vitro Study.

AIM: The aim of this study was to assess the impact of acidic drink on the microhardness of different esthetic restorative materials. MATERIALS AND METHODS: Sixty samples (20 samples of each group) were prepared. group I: nanohybrid ormocer-based composite, group II: glasiosite compomer, and group III: nanoceramic composite. A cylindrical aluminum mold of 5 mm depth and 10 mm internal diameter was used to prepare the samples. All the esthetic restorative samples were submerged in 25 mL of acidic drink (Coca-Cola) for 10 minutes each day up to 15 days. The microhardness of each sample was measured using a Vickers diamond intender. These values were matched with baseline, 7th day, and 15th day for final microhardness values. RESULTS: The mean surface microhardness of 61.13 ± 0.82 was shown by group I, which was slightly more than that in group II (59.65 ± 1.16) and group III (59.22 ± 1.30). Analysis of covariance did not show any statistically significant difference between the groups. The samples in group III showed the highest reduction in surface microhardness value after immersion into acidic drink, followed by group II and group I on 7th day and 15th day. A statistically significant difference (p < 0.001) was found on 7th day. CONCLUSION: The present study concludes that the esthetic restorative material-nanohybrid ormocer-based composite-showed the finest behavior both before and after being dipped in the acidic drink followed next by glasiosite compomer and nanoceramic composite. CLINICAL SIGNIFICANCE: The various esthetic restorative materials with different physical characteristics and colors are marketed in numerous ways. Nevertheless, all dental restorative materials show surface degradation under acidic conditions over a period of time. So, it helps to know the surface microhardness changes of various esthetic restorative materials upon repeated exposure to acidic beverages.

An In Vitro Evaluation of Fracture Resistance Strength of Different Post Systems in Endodontically Treated Teeth.

AIM: This study aimed to evaluate the fracture resistance strength of different post systems in endodontically treated teeth. MATERIALS AND METHODS: Freshly extracted 60 single-rooted first premolars were selected for this study. Conventional step-back technique was used to prepare a canal for all the teeth. Obturation was carried out and post space was created using a Peeso reamer. All teeth were randomly divided into three groups of 20 samples in each group: Group I, teeth inserted with prefabricated carbon posts; Group II, teeth inserted with prefabricated zirconia posts; and Group III, teeth inserted with prefabricated everStick posts. Core buildup was performed using light-cured composite resin. Compressive load required to fracture the tooth was measured using a universal testing machine. RESULTS: The compressive strength of zirconia posts was highest with a mean of 796.10 ± 20.78 followed by carbon posts (628.22 ± 18.11) and lower compressive strength was exhibited by everStick posts (534.13 ± 19.98). An analysis of variance revealed a statistically highly significant difference (P < 0.005) among the different posts used, and a statistically significant difference between carbon posts vs. zirconia posts, carbon posts vs. everStick posts, and zirconia posts vs. everStick posts (P < 0.05). CONCLUSION: Zirconia posts show the maximum fracture resistance than the carbon posts and everStick posts.

Comparison of Efficacy of Lycopene and Lycopene-Hyaluronidase Combination in the Treatment of Oral Submucous Fibrosis.

BACKGROUND: Oral submucous fibrosis (OSMF) is a chronic progressively scarring disease of the oral cavity. Lycopene is a powerful antioxidant obtained from tomatoes and has the highest singlet oxygen quenching capacity and a high capacity of quenching other free radicals in vitro among dietary carotenoids. Hyaluronidase is a substance prepared from the testes and semen of mammals that modifies the permeability of connective tissue through the hydrolysis of hyaluronic acid. OBJECTIVE: To evaluate the efficacy of lycopene and lycopene-hyaluronidase combination, and to compare the efficacy of lycopene and lycopene-hyaluronidase combination in the treatment of OSMF. STUDY DESIGN: The study consisted of 45 patients with OSMF divided into three equal groups. Patients in Group A were given Lycored 16 mg daily in two equally divided doses for 3 months. Patients in Group B were given LycoRed along with hyaluronidase intralesional injection of 1500 IU twice weekly for 3 months. Patients in Group C were given placebo capsules. Patients were evaluated after 3 months. The following parameters were recorded: mouth opening, visual inspection, palpatory findings, and burning sensation. RESULTS: There was statistically significant change in mouth opening and burning sensation for lycopene and lycopene-hyaluronidase combination than in the placebo group in the treatment of OSMF, but the lycopene-hyaluronidase combination did not show any statistically significant change when compared with lycopene alone. CONCLUSION: Lycopene appears to be a very promising antioxidant in the management of oral submucous fibrosis, both in clinical and symptomatic improvement.

An Ex Vivo Evaluation of Antimicrobial Efficacy of Root Canal Preparation With Hand K-Files, Hand Pro Taper, and Pro Taper Rotary Files.

BACKGROUND: Microorganisms are considered to be the primary cause behind persistent pulpoperiapical pathologies as well as endodontic failures. It has been found that Enterococcus faecalis is one of the most commonly isolated organisms in failed endodontic treatment. Proper and appropriate mechanical instrumentation is necessary to eradicate these microorganisms. AIMS AND OBJECTIVES: The aim of this study was to compare antimicrobial efficacy of various root canal instrumentation techniques. This study was designed to compare antimicrobial efficacy of root canal preparation using hand K-files, hand Pro Taper files, and Pro Taper rotary files. MATERIALS AND METHODS: Forty intact maxillary premolars extracted for orthodontic reasons were used. After extirpation of pulp, teeth are decoronated and autoclaved. Then the root canals were infected with E. faecalis suspension and the teeth were incubated at 37°C for 24 h. Thereafter the teeth were divided into five groups and were prepared using the following instruments: group 1 (hand K-files), group 2 (hand Pro Taper files), group 3 (Pro Taper rotary files), group 4 (Control I; treatment consists of irrigation with 1 mL of sterile physiological saline with no instrumentation), and group 5 (Control II; teeth received no treatment at all). Before and after treatments, samples were taken from the root canals for culture and were transferred to physiological saline. Results were evaluated after 24-h incubation in selective culture medium. RESULTS: The results showed that the teeth prepared with Pro Taper rotary files showed significant reduction in number of bacteria from the root canals.

Caries Risk Assessment of 12-13-year-old Government and Private School Going Children of Mysore City Using Cariogram: A Comparative Study.

AIM: The aim of this study is to assess the caries risk assessment of 12-13-year-old government and private school going children of Mysore city using Cariogram. MATERIALS AND METHODS: A cross-sectional examination was carried out on a total of 104 government and private schoolchildren aged 12-13 years. Ten factors from the Cariogram software(D Bratthall, Computer software, Malmo, Sweden) were included from study participant's records to complete the Cariogram. The percentage of "chances of avoiding new lesions" (caries risk) among government and private school study participants were obtained from Cariogram, and the participants were classified into five risk groups. Statistical analysis was performed using the software program Statistical Package of Social Science (version 17.0, SPSS Inc., Chicago IL, USA). RESULTS: Findings revealed that there is slight difference in caries risk among government and private schoolchildren, where 48% caries risk development and 52% chance to avoid dental caries were showed in government schoolchildren, and 51% caries risk development and 49% chance to avoid dental caries were showed in private schoolchildren, according to Cariogram. Decayed, missing, and filled teeth component, mutans streptococci, and Lactobacillus counts were slightly higher in private schoolchildren compared with government schoolchildren. CONCLUSION: The private schoolchildren had less favorable values than government schoolchildren for most of the caries-related factors. Cariogram can be the most modest and reliable tool for caries prediction, thus aiding in identifying different risk groups in a community so that appropriate preventive strategies can be provided to overcome new carious lesion formation.

Assessment of Enamel Surface Microhardness with different Fluoride Varnishes-An In Vitro Study.

AIM: This study aimed to assess the microhardness of the enamel surface after fluoride varnish application. MATERIALS AND METHODS: Thymol of 0.1% in distilled water was used to store the collected healthy sixty teeth. The samples were divided into three groups randomly as per the different applica -tion of fluoride varnish. Group A: Fluor protector varnish (FIV) application, group B: Duraphat varnish application and group C: Bifluorid 10 varnish application. The present study followed the pH cycling protocol. Microhardness tester was used to test the microhardness of enamel surface and was expressed as micro-hardness measurements of Vickers hardness number (VHN) which was performed at baseline, on the 3rd day andon 7th day. RESULTS: At baseline, group A samples mean SMH value was 230.64 ± 12.32 which was slightly more than group B with 229.45 ± 10.22 and group C with 230.10 ± 11.45. There was no significant difference showed with the analysis of variance between the groups. On the 3rd day, there was a slight increase in the mean SMH in group A with 235.39 ± 6.44 and no significant difference between the groups was seen statistically. On the 7th day, the group A showed high SMH value of 262.20 ± 4.89 compared to other groups which didn't show a significantly high statistical difference. CONCLUSION: On conclusion, post-application of fluorprotector varnish showed higher enamel surface microhardness compared to Duraphat and Bifluorid 10 varnishes. CLINICAL SIGNIFICANCE: In young children, fluoride varnishes are effectively used as a noninvasive, anti-caries agent in the treatment of initial caries. Therefore, in routine dental practice, the knowledge about different fluoride varnishes is of importance.

Evaluation of Intracanal Calcium Hydroxide Removal with Different Techniques: A Scanning Electron Microscope Study.

AIM: This study aimed to evaluate the efficacy of Intracanal calcium hydroxide removal with different techniques. MATERIALS AND METHODS: Seventy-five freshly extracted, non-carious, single canalled lower first premolars, having anatomic characteristics similar to each other, extracted for the orthodontic purpose were collected. After the root canal preparation, Calcium hydroxide was placed into the working length using lentulo spiral instrument till the medicament was visible at the apex. The specimens were segregated into three groups; Group 1: Rotary Files, Group 2: EndoVac system and Group 3: Ultrasonics. The evaluation was done with SEM in the coronal and apical third of the roots with a magnification of 1000x. The statistical analysis was done using statistical packages for social sciences (SPSS) software, version 20.0 for Windows (SPSS Inc., Chicago, IL). A p-value of less than 0.05 was considered significant statistically. RESULTS: Maximum removal of Ca(OH)2 was analyzed in the EndoVac system (2.90 ± 0.12) followed by the rotary files (1.76 ± 0.26) and least was seen with Ultrasonics (1.32 ± 0.14). The p-value of 0.001 was seen between the coronal and apical third with the EndoVac system which is statistically significant. The significant difference statistically was observed between Rotary Files vs. Ultrasonics at apical third and with the EndoVac system vs. Ultrasonics at coronal third as well as at the apical third with p-value 0.001. CONCLUSION: It can be concluded that the EndoVac technique was effective in removing Ca(OH)2 medicament from the coronal and apical third of the root canal significantly. CLINICAL SIGNIFICANCE: Calcium hydroxide removal before the obturation was of priority as the Ca(OH)2 remnants have a negative impact of the ability for sealing the obturation material. Therefore, having a complete knowledge regarding the effective technique is much important.

Evaluation of the Oral Health Knowledge, Attitude and Behavior of the Preclinical and Clinical Dental Students.

BACKGROUND: Dentists play very important role in the oral health education of the community. Thus it is important to know the status of knowledge, attitude, and behavior toward the maintenance of oral health at the student level. The aim of the present study was to evaluate the oral health knowledge, attitude, and behavior among preclinical and clinical dental students. MATERIALS AND METHODS: A cross-sectional study was conducted on 147 dental students from 1(st) to 4(th) year of Malabar Dental College, Kerala, in the year of March-June 2010 and was carried out with the help of 30 questionnaires. Age, gender and academic year data were recorded. Statistical analysis was performed with the help of SPSS version 20 using the Student's t-test and one-way ANOVA tests. RESULTS: The difference in scores of oral health knowledge, attitude and behavior between preclinical and clinical dental students was found statistically highly significant (Student's t-test, P < 0.001). The variation of scores of knowledge, attitude, and behavior also showed highly significant increase with the year of study (one-way ANOVA, P < 0.001). While the difference in scores between males and females showed that females have better oral health knowledge than males, but the difference was not statistically significant (Student's t-test, P > 0.01). The present study thus showed improvement of knowledge, attitude and behavior with the academic years and there was no bias of gender with reference to oral health. CONCLUSIONS: Although oral health knowledge, attitude and behavior showed improved results from 1(st) to 4(th) year dental students, it should be improved in order to serve better for the community in the future.