Resorption is a pathologic process that often eludes the clinician with its varied etiologic factors and diverse clinical presentations. The key cells involved in tooth resorption are odontoclasts which are multinucleated cells that produce resorption lacunae. Resorption can be classified as internal and external resorption. Internal resorption has been described as a rare occurrence as compared to external resorption. This article describes the pathogenesis of tooth resorption and various forms of internal resorption along with some clinical cases. Early diagnosis is the key factor in the successful management of resorptive lesions.

Complete debridement and disinfection of the root canal system are fundamental requirements for successful endodontic treatment. Despite the morphological challenges of the internal root anatomy, root canal irrigants play an important role in the optimization of the root canal preparation, which is essentially a chemo-mechanical procedure. Enterococcus faecalis is one of the most resistant microorganisms that dominants the microbial ecosystem of persistent periradicular lesions in retreatment cases. For that reason, many in vitro and in vivo studies evaluated and compared the antibacterial activity of sodium hypochlorite and chlorhexidine at varying concentrations using different experimental models against this microorganism. However, many controversies with regard to the ideal irrigant and concentration do in fact exist. Hence, this review aims to discuss the antibacterial activity of these two main root canal irrigants against Enterococcus faecalis using the agar diffusion and direct contact methods and the possible modulating factors responsible for inconsistent findings among different studies. In addition, the disinfection potential of both chemical agents on gutta percha and Resilon cones are also discussed. The source of this review was conducted through an electronic literature search using PubMed database from December 1997 until December 2011, which analyze the related laboratory investigations of both irrigants, published in major endodontic journals.

Aim: This experimental study was designed to focus on the effects of bleaching on toothbrush abrasion in three types of composites with different filler size. Materials and Methods: Forty eight disks were prepared from three types of composite and divided into 6 groups. In the first three groups the abrasion test was done. The remaining groups were bleached and the abrasion test was performed. The weight of the samples before and after abrasion was measured. Statistical analysis was done with one-way ANOVA and Duncan test. Results: There was a significant difference in abrasion of composites with different filler size (P < 0.05). The most amount of abrasion was observed in Z100 after being bleached. An increase in abrasion was noticed in all three types of tested composite after bleaching. Conclusion: According to the findings, it is suggested to use a nano filled resin composite for restoration if the bleaching treatment is required.

Aim: To assess awareness of school teachers concerning the emergency management of traumatized teeth. Materials and Methods: This is a prospective intervention study conducted with 1000 teachers (500 urban, 500 rural) randomly selected from the entire government and private, primary (elementary) as well as secondary (high) schools of Nellore district of Andhra Pradesh, India. Study was carried out in three phases; the first phase being an initial survey conducted to assess the existing knowledge of teachers on management of traumatic injuries by using self-administered questionnaire. This was followed by a comprehensive informative promotion regarding the initial management of the traumatic dental injuries for the teachers. A post-promotion follow-up review was conducted 3 months later to evaluate the effect of the informative promotion, using the same set of questionnaires. Study was completed over a period of 9 months. Statistical Methods: Data analysis was done using SPSS software version 14.0, and Chi-square test was used to compare the knowledge of teachers prior to and after the informative promotion. The level of significance was set at P ≤ 0.05. Results: The teachers' overall knowledge with respect to the emergency management of the traumatic injuries was deficient and significant differences were found in the knowledge of teachers before and after the informative promotion. Conclusion: Informative promotion programs to improve the knowledge and awareness of this group of community, who are generally the first line of assistance in case of dental trauma in schools, are mandatory.

Aim: To evaluate the effect of direct and indirect technique, bevel placement, and aging on the fracture resistance of composite restorations bonded to sectioned incisal edges. Materials and Methods: Incisal thirds of 80 human maxillary incisors were sectioned. Four treatment groups of 20 teeth each were formed as follows: Direct composite with bevel and without bevel (Adper single bond 2/Filtek Z350); indirect composite with bevel and without bevel (prepolymerized Filtek Z350 cemented with Adper single bond 2/Relay × ARC). Ten teeth from each group were stored in distilled water for 24 h. The remaining ten teeth were stored in distilled water for 180 days with two thermocycling treatments. The specimens were subjected to shear testing using universal testing machine. Fractured specimens were examined with a stereomicroscope at ×10 magnification to evaluate the failure patterns. The obtained data were statistically analyzed by using ANOVA, Bonferroni test, and Student's t-test. Results: Beveled restorations exhibited higher fracture resistance values than nonbeveled restorations. Long-term water storage decreased the fracture resistance. Conclusion: The use of bevels resulted in improved fracture resistance of composite restorations and reduced the impact of aging.

Aim: To measure the light transmission through different esthetic posts and to evaluate the degree of polymerization of dual cure resin cement cured through these posts. Materials and Methods: The posts were divided into two experimental groups i.e. Group A (D.T. Light post); Group B (D.T. White post) and control i.e. Group C (metal post), each group having 10 samples. Posts of each group were illuminated with curing light and photographs were taken keeping the parameters standardized to evaluate the intensity of light transmission at different levels. The degree of polymerization of dual cure resin cement was evaluated using Fourier Transform Infrared spectroscopy. The data obtained was subjected to statistical analysis. Results: D.T. Light post showed highest light transmission and degree of polymerization. The light intensity decreased from cervical to apical for both esthetic post but the decrease from middle to apical third was insignificant for D.T. White post group. No light transmission was detected in metal post but the degree of polymerization decreased significantly from cervical to middle third. Conclusion: Cementation of fibre post with superior light transmitting ability using dual cured resin cement resulted in increased degree of polymerization.

Aim: To evaluate the biocompatibility of a new root canal irrigant Q mix™ 2 in 1 in comparison to 0.9% sterile saline, 3% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), and 17% ethylenediaminetetraacetic acid (EDTA). Materials and Methods: Six circles were drawn on the dorsal skin of 24 male Wistar Albino rats, leaving 2cm between each circle. Using a syringe, 0.1mL of each root canal irrigant was injected subcutaneously into five circles. In the sixth circle, the needle of an empty syringe was introduced into the skin, but no irrigant was injected (control group). Evaluations were done at 2 hours, 48 hours, 14 days, and 30 days postprocedure. Tissue samples were excised, embedded in paraffin blocks, and 3 μm thick sections were obtained and stained with hematoxylin and eosin. The areas of inflammatory reaction were evaluated. From each tissue sample, five sections presenting the greatest inflammatory reactions were examined under a light microscope, and analyzed statistically by analysis of variance (ANOVA) and Tukey's test. Results: At the two-hour examination period, all the irrigants showed a slight increase in the number of inflammatory cells, at 48 hours, the number of inflammatory cells were increased significantly, and after 14 and 30 days, they were decreased gradually. Qmix™ 2 in 1 showed a smaller number of inflammatory cells than other irrigants tested. Conclusion: QMix™ 2 in 1 was shown to be less toxic to the rat subcutaneous tissue than 3% NaOCl, 2% CHX, and 17% EDTA.

Purpose: To compare the effectiveness of phosphoric acid (H ₃ PO ₄ )-pumice compound with conventional hydrochloric acid (HCl)-pumice compound in treating different severities of dental fluorosis with the microabrasion technique. Materials and Methods: Sixty-seven anterior teeth from seven patients with different severities of dental fluorosis were treated. In each patient, half of the teeth were treated with HCl-pumice compound and the other half with H ₃ PO ₄ -pumice compound (split-mouth design). Both treatment compounds were applied for 30-second periods and treatment continued up to 10 minutes. Before and after treatment, standardized photographs were taken. The photographs were compared by two experienced observers unaware of the modality of treatment. Two indices of aesthetics, improvement in appearance (IA) and degree of stain removal (DSR), were determined according to a visual analog scale. The inter- and intra-correlation coefficients were made; then, statistical analyses were calculated using Mann-Whitney and t-test. Results: There were no significant differences in interobserver evaluation. Improvements in aesthetic indices were observed in all fluorotic teeth by both compounds; however, the mean treatment time with HCl-pumice was significantly lower than H ₃ PO ₄ -pumice. Conclusion: The H ₃ PO ₄ -pumice compound improved aesthetic indices in fluorotic teeth similar to the HCl-pumice compound.

Objectives: To evaluate the color change in teeth bleached with two different concentrations of hydrogen peroxide, containing sweet potato extract as an additive, using a spectrophotometer, and to evaluate the surface changes in enamel using a scanning electron microscope (SEM). Materials and Methods: Baseline color values of 24 artificially stained incisors were obtained using a spectrophotometer. The specimens were divided into two groups of 12 teeth, each based on the concentration of hydrogen peroxide (H ₂ O ₂ ) as follows: Group I - 35% H ₂ O ₂ and Group II - 10% H ₂ O ₂ . One-half of the tooth was bleached with H ₂ O ₂ alone (Subgroup A) and the other half was bleached with a combination of H ₂ O ₂ and sweet potato extract (Subgroup B). Post bleaching the Commission Internationale de l' Eclairage L*, a*, b* (CIEL*a*b*) values were obtained and ΔE was calculated. The surfaces of the samples were examined using SEM. Results: The mean ΔE values of groups IB (72.52 ± 2.03) and IIB (71.50 ± 1.81) were significantly higher than those of groups IA (65.24 ± 1.02) and IIA (64.19 ± 1.88), respectively, (P < 0.05). The SEM images of groups IB and IIB showed lesser surface irregularities and morphological alterations in enamel. Conclusion: The addition of sweet potato extract to hydrogen peroxide not only resulted in the restoration of the natural tooth color, but also decreased the effects of bleaching on the enamel morphology, compared to the use of hydrogen peroxide alone.

Background: Dental pulp calcifications are unique and represent the dental pulp regenerative process. Dental pulp calcifications are sometimes routine findings in oral radiographs and may later serve as an important diagnostic criterion for a hidden aspect of systemic illness. Objective: The purpose of this study was to assess the patterns and prevalence of idiopathic dental pulp calcifications in a tertiary care setting in South India. Materials and Methods: A total of 227 patients were included in the study fulfilling the inclusion criteria. Age range of the study population was from 15 to 70 years. Teeth were examined under digital panoramic radiograph. The presence or absence of pulp stones was recorded. The presence of pulp stone were categorized according to the types classified as Type I, Type IA, Type II, Type IIA, Type II B, and Type III. The frequency of occurrence of pulp stones with sex, tooth type, dental arches, and types were compared with the types of calcification. Results: Total no. of patients with pulpal calcification were 227 [females 133 (58.59%) and males 94 (41.40%)]. The most common type between both sexes was Type I (48%). Total no. of teeth with calcification was 697; maxilla (48%), mandible (52%). The prevalence of pulp stone was found to be higher in the molars in both the arches. Most no. of pulp stones are reported at the third and fourth decade of life. Conclusion: Idiopathic dental pulp calcifications are incidental radiographic findings of the pulp tissue and also may be an indicator of underlying disease.

Aim: To assess the efficacy of 17% ethylene diamine tetra acetic acid and 7% maleic acid in the removal of 3 calcium hydroxide preparations placed as intracanal medicaments. Materials and Methods: The root canals of 60 single rooted premolars were prepared with a step back technique and randomly assigned into 3 experimental groups (n = 20). Group A was filled with plain calcium hydroxide mixed with distilled water in which barium sulfate was added for radio opacity, Group B was filled with Apexcal and Group C was filled with Metapex. After 7 days each group was divided into 2 sub groups (n = 10). The medicaments were retrieved with 17% EDTA (first sub group) and 7% maleic acid (second sub group). Along with the above irrigants manual and ultrasonic agitation was used. The pre and post removal volume of medicaments in root canals were measured using spiral computerized tomography. The percentage difference was calculated and statistically analyzed using Kruskal Wallis and Mann Whitney U test. Results: 17% EDTA and 7% maleic acid efficiently removed calcium hydroxide, distilled water mixture (P = 0.218) and Apexcal (P = 0.684), whereas 7% maleic acid showed better retrieval capability of Metapex than 17% EDTA (P = 0.002). Conclusion: Calcium hydroxide, distilled water mixture and polyethylene glycol based calcium hydroxide were efficiently removed by 17% EDTA and 7% maleic acid. 7% maleic acid removed silicone oil based calcium hydroxide preparation better than 17% EDTA.

Background: Fiber reinforced composite (FRC) posts are cemented with resin cements. It is reported that using resin cements in canals sealed with eugenol-containing sealers reduces the post retention. However, there is controversy on the subject. Aims: The aim was to investigate the influence of eugenol-containing sealers and the amount of dentin removal from root canal with different post diameters on retention of FRC posts. Settings and Design: It was an in vitro study. Materials and Methods: The roots of sixty teeth were cut with 14 mm distance from the apex and were instrumented to the working-length of 13 mm. The teeth were randomly distributed into 2 groups (n = 30). Following storage in normal saline for 7 days, the samples in both the groups were further divided into 3 subgroups (n = 10). Canals in the experimental subgroups (I, II, III) were obturated by gutta-percha and eugenol-containing sealer; and in the control subgroups (IV, V, VI) without any sealer. After storage in normal saline for 7 days, the post space was prepared by #3, #2, and #1 drills of DT Light-Post system. Post was cemented with Panavia-F2.0 resin-cement. A composite core was built for each sample. All samples were thermo cycled for 1000 cycles. The samples were tested for post retention with a mechanical testing machine. Statistical Analysis: Data were analyzed by two-way ANOVA and Tukey-HSD test. Results: There was not a significant difference in retention between FRC posts #1 and #2 (P > 0.05). Post #3 was more retentive than posts #1and #2 (P < 0.05). ZOE sealer significantly reduced the retention of posts (P = 0.024), however, increasing post-space diameter significantly increased post retention in canals coated with ZOE sealer (P = 0.002). Conclusions: Eugenol-containing sealer reduced the retention of FRC posts cemented with resin cement. Removing more dentin from root-canals treated with eugenol-containing sealer for placing larger diameter posts caused an increase in post retention.

Aim: To compare the antimicrobial efficacy of calcium hydroxide (CH), 2% chlorhexidine gel (CHX) and a combination of both, on obligate anaerobes, facultative anaerobes and Candida spp . Materials and Methods: 90 single rooted permanent teeth were included in the study. After complete disinfection and access opening, the first microbiological pre-treatment sample (S1) was collected. After completion of instrumentation, a post-instumentation sample (S2) was taken and the teeth were divided into three groups: Group I: CH, Group II: 2% CHX, Group III: 2% CHX with CH. After 1 week, a post-medication sample (S3) was collected. Results: All three medicaments were effective in the elimination of obligate anaerobes. CHX and combination showed higher antimicrobial effect against facultative anaerobes and Candida spp . in comparison with CH. But there was no statistical significant difference between Group II and Group III. Conclusion: CHX with or without CH was more effective than CH alone against all the tested micro-organisms.

Background: Two of the most critical factors affecting the prognosis of an avulsed tooth after replantation are extra oral dry time and the storage medium in which the tooth is placed before treatment is rendered. However, the ability of a storage/transport medium to support cell viability can be more important than the extra oral time to prevent ankylosis and replacement resorption. Aim: Purpose of this study was evaluation and comparison of efficacy of a new storage medium, oral rehydration solution (ORS) with coconut water, and propolis in maintaining the viability of periodontal ligament (PDL) cells by using a collagenase-dispase assay. Materials and Methods: 40 teeth were selected with intact crown which were advised for Orthodontic extraction having healthy PDL. Teeth were then randomly divided into three experimental storage solution groups. Other 10 were divided into positive and negative control groups (5 each). Statistical Analysis and Result: The results were statistically analyzed with analysis of variance and multiple range by using post hoc tests. The results of the prevailing study indicated that coconut water group demonstrated a significantly higher number of viable PDL cells than propolis 50%, and ORS. There was no significant difference between coconut water and propolis 50% groups.

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.

Aim: The aim of this study was to assess the cleaning capacity of the Protaper system using motor-driven or manual instrumentation. Materials and Methods: Ten mandibular molars were randomly separated into 2 groups (n = 5) according to the type of instrumentation performed, as follows: Group 1 - instrumentation with rotary nickel-titanium (Ni-Ti) files using ProTaper Universal System (Dentsply/Maillefer); and, Group 2 - instrumentation with Ni-Ti hand files using ProTaper Universal (Dentsply-Maillefer). Afterwards, the teeth were sectioned transversely and submitted to histotechnical processing to obtain histological sections for microscopic evaluation. The images were analyzed by the Corel Photo-Paint X5 program (Corel Corporation) using an integration grid superimposed on the image. Results: Statistical analysis (U-Mann-Whitney - P < 0.05) demonstrated that G1 presented higher cleaning capacity when compared to G2. Conclusions: The rotary technique presented better cleaning results in the apical third of the root canal system when compared to the manual technique.

Dental pulp has the ability of repair/regeneration. Indirect pulp therapy (IPT) is recommended for pulp preservation in asymptomatic teeth with extremely deep caries as well as teeth with clinical symptoms of reversible pulpitis. In this case study, we performed IPT with calcium enriched mixture (CEM) cement on a symptomatic permanent molar. After clinical/radiographic examinations the tooth was diagnosed with irreversible pulpitis and associated apical periodontitis. IPT involved partial caries removal, the placement of CEM cement pulp cap and overlying adhesive permanent restoration. At the 1 week follow-up, patient's spontaneous symptoms had resolved. One-year follow-up demonstrated pulp vitality, clinical function, as well as the absence of pain/tenderness to percussion/palpation/cold sensitivity tests; periapical radiograph showed a healing periradicular lesion with newly formed bone, that is normal pulp with normal periodontium. These favorable results indicate that IPT/CEM may be a good treatment option in comparison to endodontic treatment in young patients. IPT of deep-caries lesion is an easier, more practical and valuable treatment plan than complete caries removal.

Mandibular premolars have earned the reputation for having aberrant anatomy. The literature is replete with reports of extra canals in mandibular first premolars, but reports about the incidence of extra roots in these teeth are quite rare. This paper attempts at explaining a rare case of successful endodontic management of a four-rooted mandibular first premolar with diagnostic, interoperative and postoperative radiographic records along with a substantial data on the incidence of extra roots in these teeth. The standard method of radiographic appraisal was maintained as the criteria for determining the presence of extra roots.