Comparative assessment of nanosized intracanal medicaments on penetration and fracture resistance of root dentin - An in vitro study.

Context: The antimicrobial potential of conventional medicaments is reduced due to their limited permeability. The use of calcium hydroxide (CH) is known to reduce the root strength. Nano intracanal medicaments have the following advantages over conventional such as higher surface area and chemical reactivity, and due to its nanosize, have better penetrability, supporting its possible use as an intracanal medicament. Nano versions of CH, chitosan (CS), CS + CH, curcumin (T), and its conventional forms are used in our study. Aim: The aim of this study was to evaluate and compare the depth of penetration of nanosized intracanal medicaments and their effect on fracture resistance of root dentin. Materials and Methods: Eighty extracted single-rooted teeth were used after decoronation. Canals were enlarged up to size 30 (0.04° taper) using Neoendo instruments (Orikam, India). Teeth were randomly assigned to two broad groups based on the type of intracanal medicament used; Group A: control (conventional) (n = 40) and Group B: nanosized intracanal medicaments (n = 40). Each group was subdivided into four experimental groups (n = 10), Group A1: CH, Group A2: CS, Group A3: curcumin (T), Group A4: CS + CH, Group B1: nano calcium hydroxide (NCH), Group B2: nano CS (NCS), Group B3: nano curcumin (NT), and Group B4: NCS + nano calcium hydroxide (NCS + NCH). All the specimens were stored in a humidor at 37°C for 4 weeks. Out of 10 specimens from each group, five specimens were used for evaluating the depth of penetration using a confocal laser scanning electron microscope, and the remaining five specimens were used for evaluating fracture resistance in a universal testing machine at the end of 4 weeks. Data were analyzed using one-way ANOVA and intergroup comparison using Tukey's post hoc multiple comparison test. Results: The highest fracture resistance was seen with NCS and the maximum depth of penetration with nano calcium hydroxide (NCH). Conclusion: The fracture resistance and depth of penetration at a 4-week interval were higher in nano forms compared to their micro-sized counterparts with all groups. The coronal section presented the highest depth of penetration of intracanal medicaments followed by the middle and least in the apical section of root dentin with all groups.

Evaluation of Marginal Adaptation of Composite Restorations Reinforced with Novel Enamel Inserts (Biofillers) in Class V Cavities.

AIM AND OBJECTIVE: To evaluate the marginal adaptation at the tooth-restoration interface at enamel and cementum margins using composite restoration reinforced with novel enamel inserts/biofillers. MATERIALS AND METHODS: Standardized class V box-shaped cavities were prepared in 40 extracted maxillary first premolar teeth which were divided randomly into four experimental groups consisting of 10 samples each. Group I: Bulk placement. Groups II: Horizontal incremental technique. Group III: Restoration with precured composite balls (megafillers). Group IV: Restoration with biofillers. All the cavities were restored with visible light-activated direct restorative nanocomposite. The specimens were thermocycled for 24 hours. After thermocycling, the samples were immersed in a 1% methylene blue for 4 hours and subsequently evaluated for microleakage. Microleakage scores (0-4) were obtained from gingival margins of class V restorations and analyzed by statistical analysis. Evaluation of the data was performed by Kruskal-Wallis one-way analysis of variance (ANOVA), and Mann-Whitney U tests. RESULTS: Microleakage scores have indicated restorations with biofillers showed best results followed by megafillers, incremental horizontal build-up, and bulk filling. CONCLUSION: Biofillers provide a novel approach in improving microleakage and marginal adaptability of composite resin restorations. CLINICAL SIGNIFICANCE: Incorporation of inserts, which are capable of adequate bonding to resin and tooth, may provide improved marginal adaptability and reduce microleakage around restorative margins.

Remineralization potential of fluoride, amorphous calcium phosphate-casein phosphopeptide, and combination of hydroxylapatite and fluoride on enamel lesions: An in vitro comparative evaluation.

AIM: The purpose of this study was to evaluate and compare remineralization potential of fluoride, amorphous calcium phosphate-casein phosphopeptide (ACP-CPP), and combination of hydroxyapatite (HAP) and fluoride on enamel lesions. MATERIALS AND METHODOLOGY: Ten intact caries-free human premolars were selected. The coronal portion of each tooth was sectioned into four parts to make four enamel blocks. The baseline surface microhardness (SMH) was measured for all the enamel specimens using Vickers microhardness testing machine. The artificial carious lesion was created by immersing the specimens in demineralizing solution for 3 consecutive days at 35° The SMH of each specimen was evaluated. All the four enamel sections of each tooth were subjected to various surface treatments, i.e., Group A - Fluoride varnish, Group B - ACP-CPP, Group C - Combination of HAP and fluoride (Clinpro), and Group D - Control group; no surface treatment. A carious progress test (pH cycle) was carried out which consisted of alternative demineralization (3 h) and remineralization using artificial saliva (21 h.) for 5 consecutive days. After pH cycling, SMH readings of each specimen were again assessed to evaluate remineralization potential of each surface treatment agent. RESULTS: Data obtained were statistically analyzed using one-way ANOVA followed by Tukey-Kramer multiple comparison test which was applied to detect significant differences between different surface treatments at different phases of studies. CONCLUSION: Fluoride varnish shows higher remineralization potential of early carious lesion compare to ACP-CPP and Clinpro.

Novel treatment of in-office tooth bleaching sensitivity: A randomized, placebo-controlled clinical study.

OBJECTIVES: Aim of this clinical trial was to investigate the effect of a calcium phosphate based desensitizer paste applied prior to in-office tooth whitening on bleaching sensitivity (BS). METHODS: This crossover study was designed as randomized double-blinded, placebo-controlled trial. The desensitizer paste Teethmate AP (TAP) contains tetracalcium phosphate and dicalcium phosphate anhydrous in glycerol and polyethylene glycol, whereas placebo (PLA) is a calcium phosphate free analog. Fifty patients with sound maxillary incisors and canines were enrolled. Tooth shades were determined with a Vitapan Classic Shade guide. Randomly, TAP and PLA were applied to the left or to the right anterior teeth. After rinsing and air-drying the bleaching gel (Opalescence Boost PF 40%) was applied and left on the labial surfaces for 15 minutes. Sensitivity was recorded using a 10 cm visual analog scale (VAS) before, at 5, 10, and 15 minutes during, and at 1 hour, 1, 2, and 7 days after bleaching. Tooth whitening was determined with the shade guide after 1 day and 1 week. RESULTS: Prebleaching desensitization with TAP reduced BS significantly when compared with PLA. Between 1 and 7 days the average sensitivity scores were close to zero, whereas the average scores for PLA were significantly higher during this time interval. Independent from the desensitizing treatment after 1 and 7 days the medians of the shades were between 5 and 3.5 units brighter. CONCLUSIONS: Prebleaching desensitization with TAP was effective in reducing BS during and after tooth whitening treatment and had no adverse effect on the bleaching result. CLINICAL SIGNIFICANCE: Prebleaching topical application of a calcium phosphate containing compound reduced significantly bleaching sensitivity during a single 15 minutes treatment and up to one week with a 40% hydrogen peroxide containing gel without compromising tooth whitening.

Effect of conventional irrigation and photoactivated disinfection on Enterococcus faecalis in root canals: An in vitro study.

AIMS: A study was done to evaluate the antimicrobial efficacy of sodium hypochlorite (NaOCl) and photoactivated disinfection (PAD) on Enterococcus faecalis. SETTINGS AND DESIGN: Random sampling, in-vitro study. SUBJECTS AND METHODS: Access opening and biomechanical preparation were performed on fifty freshly extracted mandibular second premolars. The specimens were sterilized; 15 µm of E. faecalis was inoculated into each canal and incubated at 36°C for 24 h. Later, specimens were randomly divided into two groups of fifty each and following procedures was carried out: (i) conventional irrigation with 2.25% NaOCl (ii) PAD using diode laser, and toluidine blue photosensitizer. Samples were collected from each canal using sterile paper points which were deposited in brain heart infusion broth, and microbiological evaluation was carried out. STATISTICAL ANALYSIS USED: Student's t-test was used to find the significant difference in the reduction of colony forming unit (CFU) between the groups. RESULTS: The mean CFUs of the two groups showed statistically significant difference (P = 0.001). Improved antibacterial efficacy was seen with PAD group compared to conventional NAOCL irrigation. CONCLUSIONS: NaOCl alone was not effective in eliminating E. faecalis completely from the root canals. PAD compared to conventional irrigation showed the best results in removing E. faecalis from root canals.

Nonsurgical management of large periapical lesion in mature and immature teeth using different calcium hydroxide formulations: case series.

This case series evaluates the effectiveness of different calcium hydroxide formulations with various vehicles in management of large periapical lesion in mature and immature teeth. This will help clinicians to make informed judgments about which formulations of calcium hydroxide should be used for specific endodontic procedures.

Endodontic treatment of mandibular canine with two roots and two canals.

In majority of cases, mandibular canines have one root and one root canal, although 15% may have two canals. Literature report shows incidence of two-rooted canine as low as 1.7%. This article reports a clinical case of endodontic treatment of mandibular canine with two roots and two canals.

Cleaning and shaping the root canal with an Nd: YAG laser beam: A comparative study.

AIM: This study was undertaken to evaluate the effectiveness of an experimental Nd:YAG laser fiberoptic delivery system compared with conventional methods for its ability to cleanse and shape the root canal space in vitro. MATERIALS AND METHODS: Thirty-two teeth were divided into two groups. In the first group, the canals were instrumented with k files, in the second the initial preparation was done with a K file and completed with a laser beam. RESULTS: Scanning electron microscopic evaluations showed that preparation with a laser beam is possible and results in an improvement in the cleanliness of the canal walls when compared with conventional techniques. CONCLUSION: Root canal preparation using Nd:YAG laser results in cleaner dentin walls when compared to conventional methods.