Context: The lack of thorough knowledge regarding morphological and anatomical variations of the root canal system can result in failure to identify all root canals and lead to inadequate instrumentation and consequent failure of the endodontic treatment. Aims: The aim of the study was to evaluate the anatomy of single-rooted mandibular canines using micro-computed tomography (micro-CT). Subjects and Methods: Eighty mandibular canines were scanned by micro-CT to determine anatomic parameters: Vertucci's classification, number of lateral canals, roundness, and minor and major diameters. The shape of root canal orifices, volume, surface area, and convexity structure model index (SMI) were also evaluated. Analysis Used: The CTAn and CTvol software were used to three-dimensional and morphometric analysis. Results: All canals were classified as Vertucci Type I. Lateral canals were verified in 42.4% of the roots, in apical third. The canal diameters were decreased near the apex. The cross sections at the cementoenamel junction and 1 mm from the apex were oval in 38.3% and 79.4% of the canals, respectively. The mean canal volumes and surface areas were 11.48 ± 4.41 mm³ ≥ and 67.29 ± 19.18 mm², respectively. The SMI values indicated that mandibular canine was approximately rod like. Conclusions: The morphology of the root canal of single-rooted canines varied widely at different root levels.

Introduction: Matrix metalloproteinases (MMPs) play a significant role in the efficient tissue turnover and remodeling. This study focuses on the regulation of the MMPs by the protein kinases at the level of gene expression and their signaling pathways. Materials and Methods: Lipopolysaccharide-induced murine macrophage-like RAW 264.7 cell lines were obtained and maintained in Dulbecco's modified Eagle's medium plus 10% fetal bovine serum under optimal temperatures. Primers used were MMP-3 forward primer, MMP-3 reverse primer, and glyceraldehyde-3-phosphate dehydrogenase forward primer and glyceraldehyde-3-phosphate reverse primer. Total RNA was isolated, the sample was prepared, and electrophoresis was performed. The first strand of cDNA was synthesized and amplification of specific isolated gene using polymerase chain reactor (PCR). The amplified products were then separated on a 1.0% agarose gel in 1XTBE at 75 V for 3 h. The gel was stained with ethidium bromide, and the amplified product was visualized and photographed on Gel Doc system. Results: Real-time PCR showed only bands at expected size of 595 bp for internal control amplification of glyceraldehyde-3-dehydrogenase gene. Analysis was done with densitometry, and these values are compared with the negative control. Results showed a statistically significant rise in the relative levels of MMP-3-mRNA when compared with negative control at 1, 2, and 3 h. Conclusion: This study proved the significantly increased levels of MMP gene at different period, thereby it can be concluded that MMP-3 levels are higher in inflammatory conditions.

Background: A definite cause and effect relationship between tobacco use and caries are lacking in literature. Aim: The aim of this study is to determine the influence of tobacco dependence on caries development in young male adults. Materials and Methods: Three hundred healthy adult males in the age group of 20–40 years were divided into three groups containing 100 participants each. Group A: participants using smokeless tobacco; Group B: participants who smoke tobacco; and Group C: participants who have never used tobacco. Their dependence on tobacco was assessed using the Fagerstrom test for nicotine dependence. Their dental caries status was assessed using decayed-missing-filled teeth/decayed-missing-filled surfaces (DMFT/DMFS) index adopted by the WHO (1987). Observations were statistically analyzed using Mann–Whitney test, and P < 0.05 was considered statistically significant. Results: Mean DMFT/DMFS was significantly higher for Groups A and B as compared to Group C. Within Group A, mean DMFT/DMFS increased significantly with increased dependence on smokeless tobacco. Within Group B, highest DMFT/DMFS was found in participants with low dependence on smoked tobacco while least mean DMFT/DMFS was found in participants with high dependence. Conclusion: Both forms of tobacco proved to be a significant risk factor for increased caries development. Thus, tobacco use should be an important factor in caries risk assessment of patients.

Aim: This study aimed to evaluate the cleaning protocol of dentin impregnated with epoxy resin-based sealer (AH Plus) and the effects on the adhesive interface using 95% ethanol (E) or formamide solution (F) associated with microabrasion with glass microparticles (M). Methodology: Forty dentin specimens were impregnated with sealer (AH Plus). Specimens were cleansed according to the following protocols (n = 10): G1 (E); G2 (F); G3 (E = M); and G4 (F = M). No treatment was performed in G5 (control). Specimens were subjected to standard error of the mean to evaluate the residues persistence (×500) and open dentinal tubules counting (×2000). Another fifty specimens were subjected to similar procedures and cleaning protocols. Seven days later, composite-resin-made specimens were performed on dentin using etch-and-rinse adhesive system, then submitted to microshear test. Results: G2 and G4 showed higher residues' persistence and lower incidence of open dentinal tubules than G1 and G3 (P < 0.05). No difference was found between G1 and G3 or G2 and G4 (P > 0.05). Adhesive system bond strength was similar in all groups (P > 0.05). Conclusions: Microabrasion negatively affected the epoxy resin-based sealer residues' removal protocols' action; all groups presented residues on the dentin surface. However, 7 days later, the protocols did not affect the bond strength of adhesive system to sealer-impregnated dentin.

Objectives: The aim of this study is to evaluate the accuracy of linear measurements on cone-beam computed tomography (CBCT) images using three software programs and different voxel sizes. Methods: Ten human mandibles with 25 silica markers were scanned for 0.250-, 0.300-, and 0.400-mm voxels in the i-CAT New Generation (Imaging Sciences International, Hatfield, PA, USA). Thirty-five linear measurements were carried out by two examiners two times on the multiplanar reconstructions in the following software programs: XoranCat version 3.1.62 (Xoran Technologies, Ann Arbor, MI, USA), RadiAnt DICOM 2.2.9 Viewer (Medixant, Poznan- Poland) and InVesalius 3.0.0 (Centro de Tecnologia da Informação Renato Archer, Campinas, SP, Brazil). The physical measurements were made by another observer two times using a digital caliper on the macerated mandibles. ANOVA test was used to compare voxels and software programs. Pearson correlation and the Bland–atman tests were used to compare physical and virtual measurements and to evaluate the accuracy of the software programs, respectively (P < 0.05). Results: There was no statistically significant difference when the measurements were compared in acquisitions with different voxel sizes analyzed in the three software programs. There was also no difference when the measurements were compared between the software programs and the digital caliper. Excellent intra- and inter-observer reliability for the markers, physical measurements, and multiplanar reconstructions were found. Conclusion: Linear measurements in the XoranCat, Radiant, and InVesalius software programs are reliable and accurate compared with physical measurements. The different acquisition protocols using different voxel sizes did not influence the accuracy of linear measurements in CBCT images.

Background: Teeth with severe crown destruction and endodontically treated may or may not present a circular strip of dental tissue located in the cervical region called ferrule. Aims: The aims of this study were to evaluate ferrule thickness influence on endodontically treated teeth (ETT) resistance to fracture. Materials and Methods: A total of 30 bovine incisor teeth were selected, endodontically treated and randomly distributed, according to the ferrule thickness: G1- no ferrule, G2 – 1 mm, and G3 – 2 mm. All the teeth were restored with prefabricated posts and composite resin. Resistance to fracture was established as the compression strength at 45° tilt at the lingual surface of the crown. Statistical Analysis Used: Data were analyzed using ANOVA and Tukey's test. Results: Resistance to fracture of G1 and G2 were significantly higher than that of G3 (P < 0.001). The pattern of fracture, common to all groups, occurred at the composite resin on the coronary portions. Conclusion: Ferrule thickness can influence the resistance to fracture of ETT.

Aim: The aim of this study was to evaluate the shear bond strength (SBS) of self-adhering flowable composites on the dentinal surface prepared with carbide and diamond burs. Materials and Methods: A total of 64 extracted mandibular molars were mounted on acrylic resin blocks, and the coronal part of the dentin was exposed and polished. Then, they were divided into Group 1 and Group 2 for carbide and diamond bur preparation, respectively. Two teeth in each group were evaluated under scanning electron microscope, ×500, to view the surface changes following the bur preparation. The remaining teeth were subdivided into Groups A, B, and C to be restored with Constic, Dyad™-flow, and Tetric N Flow composites, respectively. Then, the specimens were stored in distilled water at 37°C for 24 h, and then subjected to universal testing machine to evaluate the SBS and viewed under light stereomicroscope to evaluate the type of failure. Statistical Analysis: SPSS version 22 (IBM Corp) for Windows was used for statistical analysis. The values were subjected to ANOVA followed by Bonferroni post hoc analysis. The values between the groups were analyzed using Student's unpaired t-test. Results: Statistically significant differences in the SBS values were seen between Groups A and C (P < 0.001) and Groups B and C (P < 0.001). Statistically significant differences were seen in SBS values of Dyad-flow (Group B) (P < 0.004) and Tetric N flow (P < 0.007) for surfaces prepared with carbide and diamond burs. Conclusion: It was concluded that the SBS of Tetric-N Flow was higher than that of the experimental groups of Constic and Dyad-flow. Dentinal surface preparation with carbide bur resulted in higher SBS for Tetric N Flow and Dyad-flow but not for Constic.

Aim: The aim of this study was to evaluate and compare the fluoride ion release and uptake of glass ionomer cement GP IX Extra (GE), EQUIA^® Forte Fil (EF), Beautifil Bulk (BB), Dyract^® XP (DXP), Tetric N-Ceram^® (TNC) in vitro. Materials and Methods: The restorative materials were divided into five groups (n = 12), namely G1 – GE, G2 – EF, G3 – BB, G4 – DXP, G5 – TNC. Fluoride release was checked using fluoride ion-selective electrode (Orion 9609BNWP, Ionplus Sure-Flow Fluoride, Thermo Scientific, USA) at time intervals of 1 day and thereafter at 3, 7, 14, 21, and 28 days. Following this, fluoride recharge was done with 1.23% acidulated phosphate fluoride gel (12,300 ppm, Pascal International Inc., 2929 Northup Way, Bellevue, USA) after 28 days and each sample was re-checked for fluoride release at the same time intervals. Statistical Analysis: One-way ANOVA with post hoc Games–Howell test for intergroup and repeated measures ANOVA with post hoc Bonferroni test for intragroup analysis. P < 0.05 was considered statistically significant. Results: On intergroup analysis, Group 2 showed high values of fluoride release and recharge at all-time intervals which were significantly higher (P < 0.001) than Groups 1, 3, 4 and 5. Intragroup analysis showed significantly higher (P < 0.001) fluoride release and recharge at the end of day 1 which decreased progressively with time for all the tested materials. Conclusion: EF showed the highest fluoride release and recharge potential across all time intervals compared to other tested restorative materials and the greatest fluoride release was seen on day 1.

Objectives: The specific objective of this in vitro study was to determine whether the current flowable resin composites can establish an effective seal in repairing noncarious amalgam margin defects. Material and Methods: A total of 30 freshly extracted caries-free human third molars were used for this investigation. Class I preparations with a standardized 160-μ marginal defect were made by condensing amalgam against a Mylar strip. Accelerated aging and corrosion protocols were then applied to simulate oral conditions. The prepared teeth were randomly divided into five groups (n = 6 per group) according to the repair material employed as follows: (1) no treatment (control); (2) self-adhering flowable resin composite (Vertise Flow); (3) flowable resin composite (Filtek Ultimate Flowable); (4) sonic-activated resin composite (SonicFill); and (5) self-adhesive cement (SmartCem2). Specimens were thermocycled again and then immersed in 5% methylene blue at 37°C for 24 h. For dye-leakage measurements, specimens were sliced longitudinally using a low-speed diamond disk. Results: The results indicated that the flowable resin composite material significantly reduced marginal microleakage compared to the control and SonicFill (P < 0.05). Conclusion: Current flowable resin composites were found to be adequate materials for repairing noncarious amalgam margin defects.

Aim: This study aimed to evaluate the residual filling material and the reestablishment of working length (WL) and apical patency after retreatment of BioRoot™ RCS, versus TotalFill^® BC Sealer, and AH26, used in a single cone obturation technique. Materials and Methods: Sixty single-rooted permanent canines were instrumented up to size 40/.04 (Sendoline, Täby, Sweden). The samples were filled with GP/AH26 (Group 1), GP/TotalFill BC Sealer (Group 2), and GP/BioRoot RCS (Group 3). Eight teeth were used in the positive and negative control groups. Canals were retreated using the Protaper Universal retreatment files (Dentsply Maillefer, Ballaigues, Switzerland) and further instrumented up to size 50/.04 (Sendoline, Täby, Sweden). The ability to reestablish WL and apical patency was recorded. Furthermore, the samples were observed under a scanning electron microscope, in order to evaluate the residual filling material. Data were analyzed statistically with the Fisher's exact and the Kruskal–Wallis tests (P < 0.05). Results: There was no statistically significant difference in the WL and patency recovery among the groups. Neither the intragroup comparison among canal thirds nor the intergroup comparison in each canal third or in total canal area revealed any significant differences in the percentage of the remaining filling material after retreatment. Conclusion: Residual material debris was observed in all samples regardless of the sealer used. All the sealers were removed to a similar extent. The WL and patency were reestablished sufficiently in all groups.

Aim: This study aimed to compare the canal-centering ability, apical transportation, and remaining dentin thickness (RDT) of OneShape and WaveOne (WO) systems using cone-beam computed tomography. Objective: The objective of this study was to evaluate the efficiency of two rotary systems in maintaining original root canal anatomy. Materials and Methods: Forty extracted human single-rooted mandibular premolars were used in the present study. Preinstrumentation scans of all teeth were taken, canal curvatures were calculated, and the samples were randomly divided into two groups with twenty samples in each group: Group 1 – OneShape (OS) rotary system and Group 2 – WO reciprocation system. Postinstrumentation scans were performed using DICOM software and the two scans were compared to determine the canal-centering ability, canal transportation, and RDT at 1, 3, and 5 mm from the root apex. Results: Using Student's unpaired t-test, results were as follows: for canal-centering ability and RDT, Group 1 showed nonstatistically significant difference at 1 and 5 mm, while statistically significant difference (P < 0.05) at 3 mm was obtained. For canal transportation, Group 1 showed statistically significant difference (P < 0.05) at 1 and 3 mm and nonsignificant difference was obtained at 5 mm, but for Group 2, nonstatistically significant difference (P > 0.05) was obtained at 1, 3, and 5 mm. When comparing the RDT between both the groups, the difference was not statistically significant (P > 0.05). Conclusion: WO single reciprocation file has better canal-centering ability, maintains original canal curvature, causes lesser canal transportation, and preserves more dentine as compared to OS.

Aim: The aim is to test the antimicrobial activity of Andrographis Paniculata, Azadirachta indica (neem), and Curcuma Longa (curcumin) as a root canal irrigant, against Staphylococcus aureus and Candida albicans using agar diffusion test. Sodium hypochlorite (NaOCl) served as a standard control for comparisons. Materials and Methods: The bacterial strains of C. albicans and S. aureus culture were grown overnight (18–20 h) in the brain heart infusion broth at 37°C and inoculated in Mueller–Hinton agar plates. Antibacterial inhibition was assessed using agar well-diffusion method using the methanolic extracts of the three plants to be tested and NaOCl. Bacterial inhibition zone around each well was recorded. The results were tabulated and analyzed statistically for significance. Results: The novel A. paniculata showed significantly higher zone of inhibition against C. albicans (P < 0.0001) compared to the experimental irrigants. Against S. aureus, it exhibited similar results as that shown by NaOCl (P > 0.05). Conclusion: Zones of inhibition exhibited by novel herbal agent A. paniculata were higher against C. albicans and similar against S. aureus, when compared to NaOCl.

Introduction: This study evaluated and compared techniques of postspace preparation for induction of dentinal microcracks utilizing microcomputed tomography (CT). Materials and Methods: A total of 45 extracted micro-CT scanned mandibular premolars were prepared and obturated. After the second micro-CT, samples were divided into three groups (n = 15). In Group 1, postspace preparation was done using hand K files up to the size of #110. In Group 2, postspace preparation was done using Peeso reamer up to the number of #3. In Group 3, postspace preparation was done using ParaPost XT Drills with the tip diameter of 1.1 mm. Thereafter, the third micro-CT scan was performed for microcracks evaluation, and statistical analysis was performed. Results: Few unprepared samples showed the presence of microcracks (1.54%). There was statistically significant (P < 0.05) percentage increase in the number of microcracks after root canal preparation and obturation (5.44%) and after postspace preparation (8.35%). The percentage increase in microcracks observed for Group 1, 2, and 3 from obturation to postspace preparation was 0.19%, 4.21%, and 6.86%. There was a significant difference among the three techniques of postspace preparation (P < 0.05). Conclusion: Microcracks may exist preoperatively. Postspace preparation increased the number of microcracks irrespective of the technique utilized. ParaPost XT Drills produces maximum microcracks in the root dentin followed by Peeso reamers and K files.

Introduction: With the introduction of tooth-colored restoration material, the usage of amalgam has reduced over years. However, results regarding toxicity and health concerns are conflicting. Based on the concept of recycle and reuse, we previously used an ayurvedic method for purification of excess mercury obtained from dental operatory. In the present study, we aimed to evaluate the properties of dental amalgam using commercially available and ayurvedically recycled mercury. Materials and Methods: Samples were prepared for analysis of mean compressive strength, Vickers hardness number, and coefficient of friction dental amalgam using commercially available and ayurvedically recycled mercury. Further analysis was done using scanning electron microscopy. The data were presented on Microsoft Excel Spreadsheet 2013 and statistical analysis was done on IBM SPSS software (IBM Analytics) and OriginPro 8 software. Results and Conclusion: No statistically significant difference was found in properties of dental amalgam prepared using commercially available and ayurvedically recycled mercury. Although not statistically significant, early compressive strength and hardness of amalgam using ayurvedically recycled mercury were comparatively higher, which may be attributed to residual amounts of silver, tin, and copper acting as nucleating agent for faster setting reaction.

Context: The initial bond strength and potential durability of an adhesive restoration are significantly affected by regional variations in dentin composition. Aim: The aim of this study is to evaluate the influence of dentin location and thermomechanical cyclic loading on microtensile bond strength of bulk-fill composite resin to coronal dentin. Materials and Methods: Disto-occlusal cavity preparations were done on 60 extracted human mandibular molars with pulpal floor depth of 1.5 and 3.5 mm for superficial and deep dentin and 1.5 mm axial wall depth and are restored with bulk-fill restorative composite. Bond strength evaluation was done using universal testing machine, and mode of bond failure was observed under scanning electron microscope. Statistical Analysis: Statistical analyses were done using ANOVA and Tukey's multiple post hoc test. For comparison of failure mode, Mann–Whitney U-test was used. Results: Superficial dentin has shown higher bond strength compared to deep dentin and gingival wall dentin (P = 0.001). The bond strength values decreased with the thermomechanical cycling (P = 0.001). Deep dentin and gingival dentin have exhibited more of adhesive failures. Conclusion: Bond strength of bulk-fill composite was negatively influenced by the depth of dentin and thermomechanical loading.

Background: Endodontic-periodontal pathogens exist as biofilms which are difficult to eliminate. Biosynthesized silver nanoparticles (AgNPs) emerged as newer antimicrobial agents with potential benefits. Aim: The aim of this study is to determine the minimum inhibitory concentration (MIC); evaluate the antibiofilm efficacy of fungal-derived AgNPs against Porphyromonas gingivalis, Bacillus pumilus, and Enterococcus faecalis. Materials and Methods: MIC of AgNPs against test pathogens was determined using micro broth dilution method. Serial dilutions of AgNPs ranging from 80 to 1 μg/ml concentration were added to wells containing 10 μl of bacterial inoculum in culture media and control group without AgNPs. For biofilm models, 120 dentin blocks were prepared, sterilized, and contaminated for 2 weeks with (n = 40 each). Group 1: B. pumilus, Group 2: E. faecalis, and Group 3: P. gingivalis and each group is divided into four subgroups (n = 10 each) and treated with distilled water, AgNPs, 2% and 0.2% chlorhexidine (CHX). Colonies counted after 24 h of incubation and statistically analyzed using one-way ANOVA and post hoc Tukey tests. Results: MIC for B. pumilus was determined as 20 μg/ml and 30 μg/ml for E. faecalis and P. gingivalis. AgNPs were effective as 2% CHX against all biofilms compared to control group. Post hoc Tukey test (P < 0.0001) shows no significant difference between groups. Conclusion: Fungal-derived AgNPs are effective against endo-perio pathogens.

Background: With the evolution of bonded restorations, visible light-curing units became inseparable from the practice of dentistry. This study was designed to evaluate light intensity output of light-emitting diode (LED) units used in private clinics in Riyadh, Saudi Arabia, and to investigate dentists' knowledge and attitude regarding the usage of light-curing units. Methodology: Two hundred randomly selected LED units' light intensity output was evaluated using Demetron^® LED Radiometer-Kerr among evenly distributed private clinics in Riyadh, Saudi Arabia. Three measurements of 20 s were taken, and average values were obtained. Furthermore, Output intensity measurements were subcategorized into three groups; <400 mW/cm² – inadequate intensity, 400–850 – marginal intensity, and more than 850 – adequate intensity. In addition, 100 questionnaires of ten close-ended questions, investigating demographics, knowledge, and attitude toward visible light communication (VLC) units, were filled by the same private clinics' dentists and data were collected and analyzed by SPSS. The investigation was started after official processing and agreement achieved between the investigators and the private clinics' administrators to get their full cooperation. Results: Majority of dentists (78%) reported that they do not measure the light intensity output and 9% of the measured light intensity output of LED units was found of inadequate intensity, 40.5% of marginal intensity, and 50.5% of adequate intensity. Moreover, only 31% knew the minimum accepted wavelength of VLC units. Conclusion: Dentists among private clinics express poor knowledge, maintenance, and attitude toward VLC units. Educational programs are advisable, and routinely monitoring of VLC units is recommended.

Aim: Based on the importance of coronal sealing right after endodontic treatment, this in vitro study aimed to evaluate the difference of shear bond strength to pulp chamber dentin treated with sodium thiosulfate and proanthocyanidin (PA). Materials and Methods: Fifteen extracted mandibular molar teeth were decoronated at the level of cementoenamel junction horizontally. The individual teeth were then sectioned mesiodistally to expose the pulp chamber dentin using a diamond disc. The specimens were randomly divided into three groups (n = 10). Group A: control group, treated with 5.25% sodium hypochlorite (NaOCl) for 30 min followed by a final rinse with 17% ethylenediaminetetraacetic acid (EDTA) solution for 3 min; Group B: after pretreatment with NaOCl and EDTA, it is further treated with 5% sodium thiosulfate (Na₂S₂O₃) for 10 min; and Group C: after pretreatment with NaOCl and EDTA, it is further treated with 6.5% PA for 10 min. After drying the specimens, a bonding agent namely One Coat Bond SL (SwissTEC, Coltene) was applied to the pulp chamber dentin followed by a composite restoration (SwissTEC, Coltene). Each specimen was then tested under a universal testing machine at the dentin/resin interface to determine the shear bond strength. Results: Both the groups in which 5% Na₂S₂O₃ and 6.5% PA were used for 10 min showed bond strength that was found to be statistically higher than the positive control (P < 0.05). Conclusion: The use of Na₂S₂O₃ and PA can significantly increase the bond strength of composite resin to NaOCl/EDTA-treated dentin, allowing adhesive restorations to be immediately applied after endodontic treatment.

Aim of the Study: Bacteria that persist at the time of obturation increase the possibility of persistent apical periodontitis. An ideal sealer should be able to kill these remaining bacteria that are present on the dentinal walls as well as inside the dentinal tubules. This could be possible if a sealer has antimicrobial properties with optimum flow characteristics. Hence, the aim of this in vitro study was to assess the antimicrobial efficacy of epoxy resin-based sealer: AH Plus and Perma Evolution against Enterococcus faecalis on the 1^st, 3^rd, 5^th, and 7^th day and also to compare the flow characteristics of both epoxy resin-based sealers. Materials and Methods: E. faecalis ATCC 35550 strain was used to assess the antibacterial efficacy of sealers by agar-diffusion test (ADT) and direct-contact test (DCT). Flow characteristics of sealers were measured according to the ADA specification no. 57. Results: In ADT, Perma Evolution sealer showed larger zone of inhibition than AH plus on the 1^st, 3^rd, 5^th, and 7^th day, and in DCT, both sealers were equally effective in inhibiting E. faecalis growth on the 1^st, 3^rd, 5^th, and 7^th day. Flow test showed no significant difference between Perma Evolution and AH Plus sealer. Conclusion: Both the tested sealers were equally effective against E. faecalis up to 7 days of incubation period. Considering flow properties, both the tested sealers showed optimum flow as per the ADA specification no. 57.

Objectives: The aim of this study was: (i) to formulate pit and fissure sealants (PFS) containing nano-hydroxyapatite (nHAP) filler; nHAP filler and silica co-filler; nHAP and nano-Amorphous Calcium Phosphate (nACP) co-filler, (ii) to evaluate physical properties; degree of conversion (DOC), curing depth (CD) and mechanical properties; microshear bond strength (MBS) of fortified PFS, and (iii) to assess remineralization potential and release of Ca²⁼ and PO₄ ions from newly synthesized sealants. Materials and Methods: Four PFS were prepared using monomers with mixture of 35.5 wt % BisGMA, 35.5 wt % triethylene glycol dimethacrylate and 28 wt % hydroxyethyl methacrylate. Bioactive nanofillers (nHAP and n-ACP) were added in various concentrations (0%–30%). Three commercial sealants were used as follows: unfilled (Clinpro; 3M ESPE), Fluoride releasing (Delton FS plus, Dentsply), ACP filled (Aegis, Bosworth). The samples (n = 35.5/gp) were tested for MBS, DOC, and CD. Remineralization potential was assessed by scanning electron microscopy (SEM). The concentrations of Ca²⁼ and PO₄ released from the sealant specimens were analyzed with Ultraviolet-visible Spectrophotometer. Data obtained was statistically analyzed (one-way analysis of variance, Tukey's test, P < 0.05). Results: 10% hydroxyapatite (HAP) =20% ACP sealant showed significantly higher DOC. A remineralized region on the surface between fissure sealant and tooth enamel was observed by SEM in all three HAP filled bioactive sealants. Decreasing the solution pH significantly increased ion release from sealant filled with 10% nHAP = 20% nACP (P ≤ 0.001). Conclusion: Results suggested that admixture of nHAP and nACP to PFS showed remineralizing capability, without declining their mechanical and physical properties.

The procedure of regeneration has shown promising results in the treatment of nonvital teeth with immature apices. However, the tissue being regenerated can only be confirmed through histological examination. This report describes an immature nonvital 12 with apical pathology which was treated via revascularization using 3% NaOCl and 17% ethylenediaminetetraacetic acid as irrigants; Ca(OH)2 as intracanal medicament and platelet-rich fibrin (PRF) as scaffold. On follow-up at 6 and 12 months, healing of periapical lesion, dentinal thickening, and apical closure with a canal exit forming distally were evident. The tooth, however, got fractured and was subsequently extracted at 12 months and sent for histopathological examination. It was revealed that a collagenous matrix for forming hard tissue similar to acellular cementum with a diffuse area of calcification could be seen in pulp space being attached with root canal dentin walls, suggesting that PRF may yield favorable outcomes in regenerative endodontic procedures.

Dens invaginatus (DI) is a dental developmental abnormality, probably resulting from an infolding of the dental papilla during tooth development. The following case report presents a case of Type III DI with apicomarginal defect and peri-radicular lesion, diagnosed with cone-beam computed tomography scan and treated with combined orthograde endodontic therapy and peri-radicular regenerative surgery. Follow-up examination at 2 years revealed uneventful healing and improvement in the status of the tooth-supporting structures.