Introduction: Clinical dentistry and primary oral care continue to experience significant improvements in quality at different levels of dentistry. These changes and improvements are of great benefit to both patients and clinicians because of significant achievements and advances in the physical, chemical, and biological sciences. Nanotechnology and its varied products are eloquent examples of these revolutionary trajectories in scientific discoveries and endeavors. Scientific revolution of nanotechnology has afforded the dental profession with a wealth of novel nanobiomaterials, templates for dental tissues regeneration, oral fluid nanodiagnostics, and the potential ability to use nanoparticles to replace lost dental hard tissues. Materials and Methods: A manual and systematic electronic search was conducted using the PubMed database. Several keywords were used: “nanocharacterization” “nanoclinical applications” “endodontics” “nanodentistry” “nanotechnology (263) (278) papers were excluded because they were duplicated papers,” “nanoparticles” and “regeneration.” Relevant articles published up to 2016 in the English language were retrieved. Results: Initial electronic and manual searches identified (571) studies. Preliminary analysis was performed on a total of (332) publication by screening titles and abstracts of articles. A second phase, data studies, or unrelated reports were excluded. Full texts of the remaining (54) papers were retrieved. A manual search added (6) publications on the topic to give a total of (60) publications, literature reviews, which were included in this review. Conclusions: Physical and chemical improvements in nanotechnology products continue to occur and may soon lead to the development of “smart” endodontic therapeutic agents and materials. The future looks auspicious for sustained dramatic inventions in novel nanomaterials for clinical dental applications.

Aim: This study aims to determine the current trends in endodontic irrigation practice among general dental practitioners (GDPs) in Saudi Arabia. Methodology: An invitation to participate in a questionnaire was electronically sent to 500 affiliates of the Saudi dental association. The members were queried about the irrigation solution(s) they utilize, reasons affecting their selection of irrigant, the concentration of irrigant, the removal of smear layer, the use of an intracanal medicament, the depth of penetration and gauge of the needle used for irrigation, and participation in a course related to endodontic irrigation. Results: Two hundred and thirteen responses were obtained out of 500 questionnaires sent, 50 of the received questionnaires were answered by a non-GDP and were excluded from the study, leaving 163 responses (32.6%). Our result indicates that 92% of responders use sodium hypochlorite (NaOCl) as their primary irrigant. The main concentration of used NaOCl was 0.5%–1.5% used by 36.8% of responders. 68.7% of responders claimed that they are aiming routinely to eliminate smear layer during root canal treatment. More than half of the participants did not attend any seminars in the field of endodontic irrigation after their scale. Conclusion: Most of the responders are using NaOCl as a primary irrigant, routinely removing the smear layer, and are using intracanal interappointment medicament. However, the consequences of this survey revealed that there is a big need to enhance and monitor the approach utilized by the dentist in Saudi Arabia.

\Aim: The aim of the study was to evaluate the ability and efficiency of dental students and new graduates of College of Dentistry at King Saud University in Riyadh to select the appropriate methods of restoring endodontically treated anterior teeth (ETAT) at different conditions. Materials and Methods: A questionnaire was distributed among 4^th-and 5^th-year dental students and new graduates of College of Dentistry at King Saud University in Riyadh. Only students who were pursuing clinical training in prosthodontics were included in this study. Respondents were requested to indicate their gender, level of education, and to select the preferred restoration of ETAT at different conditions. The results were analyzed by one-way frequency and two-way cross-tabulations. Results: The response rate was 98%. When more than 50% of tooth remains A, 94.4% of respondents selected a tooth-colored restoration, whereas 37.3% selected a tooth-colored restoration and a crown when 50% of tooth remains B. When <50% of tooth remains C, 53.6% selected a cast post and core and a crown. Statistically significant relationships existed between the selected restorative method at B and the gender (P = 0.005) and level of education (P = 0.000) and between the restorative method at C and the level of education (P = 0.016). When teeth serve as abutments for fixed or removable partial dentures, more advanced methods of restoration were selected. Conclusions: Selection of the appropriate method of restoring ETAT at different clinical conditions by students and new graduates was evident.

Aim: The aim of this study was to evaluate and compare dentinal microcracks formation during root canal preparation by different commercially available nickel-titanium (NiTi) file systems. Materials and Methods: Eighty-four single-rooted mandibular premolars were selected. All specimens were decoronated and divided into seven groups of 12 each. Teeth were mounted in the acrylic block with simulated periodontal ligaments. Twelve teeth served as a control in which no treatment was performed. Experimental groups were instrumented with Hand NiTi, ProTaper universal, ProTaper Next, Silk, WaveOne, and self-adjusting files (SAF). Roots were then sectioned 3, 6, and 9 mm from the apex, and the cut surface was observed under a stereomicroscope and checked for the presence or absence of dentinal microcracks. Results: SAF group and Hand NiTi group showed no cracks formation along with control group. ProTaper rotary files showed more number of cracks than ProTaper Next, Silk and WaveOne used in the study. However, no statistically significant difference was found among ProTaper rotary, ProTaper Next, Silk, and WaveOne (P > 0.05). Conclusion: All rotary files created microcracks in the root dentin at all three levels, whereas the SAF and hand files presented with satisfactory results with no dentinal microcracks.

Aim: This study aims to examine the cytotoxic effects of BioPure MTAD and three clinical concentrations of sodium hypochlorite (NaOCl) solutions (1%, 3%, and 5%) on cultured human periodontal ligament (PDL) cells. Materials and Methods: Human PDL cells were grown on cell culture plates and were placed in contact with various concentrations of tested irrigants. Cytotoxicity of both BioPure MTAD and different concentrations of NaOCl was assessed for immediate short-term intervals (1, 5, 10, and 15 min) and midterm intervals as well (24, 48, 72, and 96 h). Different parameters of toxicity such as lactate dehydrogenase assay and trypan blue dye exclusion assay were studied along with morphological changes at all the different time points. The mean zones of inhibition were calculated for each group and were statistically analyzed. Results: BioPure MTAD was least toxic of all test irrigants in short-term and midterm time intervals. 5% NaOCl showed the maximum cytotoxicity at short-term time intervals. All cells died within the first 24 h for all three NaOCl concentrations. Conclusions: BioPure MTAD showed minimal toxicity and the three concentrations (1%, 3%, and 5%) of NaOCl showed detrimental effects on the PDL cells and its toxicity was dose dependent.

Aim: The aim of this study is to investigate the type of endodontic irrigants used in cases with different pulpal diagnoses by general dental practitioners (GDPs) and specialists. Materials and Methods: A questionnaire on irrigant selection was designed and distributed to GDPs, endodontists, and advanced restorative specialists with advanced endodontic training in Riyadh, Saudi Arabia. Participants were asked to select the irrigant(s) they used in vital, necrotic, and retreatment cases and to select the irrigant they think is the best. Results: A total of 261 dentists responded: 65% were GDPs, 21% were endodontists, and 14% were restorative specialists. Sodium hypochlorite (NaOCl) was the most commonly used irrigant (65%–80%) followed by saline. Other materials such as local anesthetic solutions, chlorhexidine, and ethylenediaminetetraacetic acid (EDTA) were also used. Diagnosis of the case significantly affected the choice of irrigant. NaOCl was selected more in necrotic than in vital or retreatment cases. The endodontists used NaOCl and EDTA as an adjunct significantly more than GDPs, who significantly favored saline (P < 0.001). Choices of restorative specialists were better than GDPs but were not statistically significant than either groups. Conclusion: This survey shows that irrigant selection is affected by case diagnosis and specialty training.

Objective: This study compared the shaping ability of the ProTaper Gold (PTG) and WaveOne Gold (WOG) systems in simulated L-and S-shaped root canals. Materials and Methods: Forty L-and S-shaped root canals in resin blocks were randomly divided into four groups (n = 10). Each canal was prepared to the standard working length (16 mm) and enlarged to an apical size 25 using PTG set of files in the sequence S1, S2, F1, and F2 at a speed of 300 rpm and a torque of 2.5 N cm until each file reached the working length. For WOG, primary file was used in a reciprocating motion until the working length was achieved. The canals were photographed before and after instrumentation using different colors. The two images were superimposed, five points were selected, and canal widths were measured with image analysis software. The preparation time, instrument failure, and presence of aberrations were noted and compared between systems. Results: Findings revealed a highly significant difference (P < 0.001) in preparation time between instruments. A total of nine aberrations in the danger zones of PTG/L-shaped (1), PTG/S-shaped (4), WOG/L-shaped (1), and WOG/S-shaped (3), canals were noted. WOG/L-shaped canals were wider at the canal orifice than PTG/L-shaped canals (P < 0.05), but PTG use resulted in a greater width at the halfway point of the straight section and the beginning of the curve than WOG (P < 0.05). PTG/S-shaped root canals were wider at the beginning of the first curve of the prepared canal (P < 0.05). Conclusions: The WOG system demonstrated better shaping ability, fewer canal aberrations, and more rapid preparation than the PTG system. All files straightened the curvature of multicurved canals in the apical region.

Aim: The present study evaluated the tissue-dissolution ability of 3% sodium hypochlorite (NaOCl) and two other irrigants, namely, 10% calcium hypochlorite and 13.8% chlorine dioxide (ClO₂) at different temperatures, keeping isotonic saline as control. Materials and Methods: The bovine muscle tissue specimens which were prepared for the study, were weight adjusted (50 ± 5 mg). One hundred and twenty frozen tissue samples were distributed equitably between the four groups. The experiments were conducted at three different temperature slabs, that is, room temperature, 37°C and 45°C, respectively. The 30 tissue samples in each group were immersed in 5 mL of the allocated test solution at the desired temperature for a total of 20 min, with change of solution done every 2 min. At the end of the 20-min experiment period, the tissues were carefully removed, blotted dry on absorbent paper, and weighed on a precision balance. The percentage weight loss of the specimens was then recorded for the experiment period. Results: The results of this study showed that at room temperature, the 3% NaOCl solution presented maximum tissue dissolution, whereas at 37°C, 13.8% ClO₂solution was most effective in dissolving the tissue. However, when the temperature was raised to 45°C, all the three test solutions were equally effective in their tissue-dissolving capacity. Conclusion: The present study showed that heating the solutions enhances their ability to dissolve organic material.

A persistent infection after cleaning and shaping a root canal is the main etiology of root canal treatment (RCT) failure. Enterococcus faecalis has been considered as one of the most resistant species post-RCT. E. faecalis can stimulate toll-like receptor 2 (TLR-2) which can increase nuclear factor-kappa B (NF-κB) in chronic apical periodontitis. East Java propolis has in vitro antibacterial and biocompatible effects. Aim: This study aimed to analyze the effectiveness of East Java propolis extract as a potential intracanal medicament in chronic apical periodontitis caused by E. faecalis bacterial infection by the decrease of TLR-2 and NF-κB. Materials and Methods: Maceration method was conducted for propolis extract. This study used thirty Wistar rats which were divided into three groups, a negative control (Group I); a positive control that the first upper right molar root canal induced with E. faecalis ATCC29212 and filled using glass ionomer cement (GIC) (Group II) and treatment group that the first upper right molar root canal induced with E. faecalis ATCC29212 and 10 μl propolis was applicated and filled using GIC (Group III). After 21 days, those rats were sacrificed, and then immunohistochemical examination was conducted to investigate the expressions of TLR-2 and NF-κB. Results: The mean of TLR-2 and NF-κB expressions on Group III was significantly lower than that of the positive control group (P < 0.05). Conclusion: It can be concluded that East Java propolis extract is a potential intracanal medicament in chronic apical periodontitis caused by E. faecalis infection by decreasing the expression of TLR2 and NF-κB.

Canal calcification and obliteration is considered a challenge during root canal treatment. The present case report demonstrates a successful management of calcified pulp chamber and coronal third of the root canals of lower right first molar tooth of a 17-year-old patient that was diagnosed as previously initiated with symptomatic apical periodontitis treated by pulpotomy for a long period. It also emphasizes the use of the aiding tools to negotiate such calcification including intraoperative cone-beam computed tomography. This technology, along with chelating agents, magnification, illumination, and ultrasonic instruments helped in assessing the extent and the depth of the calcification and guided the clinician to the correct location, angle, and depth to negotiate the patent part of the canals, and therefore adequately treated.

Management of immature permanent teeth exhibiting symptomatic or necrotic pulp is clinically challenging. Appropriate diagnosis and case selection, and good management, ensure good outcomes. Here, the management of the bilateral, immature, permanent mandibular first molars of a 5.6-year-old male who exhibited reversible pulpitis of the mandibular first right molar (tooth #46) and normal apical tissue and pulpal necrosis with asymptomatic apical periodontitis of the mandibular first left molar (#36) is presented. The former tooth was managed using vital pulp therapy (pulpotomy) and the latter employing revascularization. Follow-up examinations revealed complete formation of the mesial and distal roots of tooth #46, complete formation of the mesial root, but incomplete formation of the distal root of tooth #36, with radiolucency evident within the root.

Treating teeth with invasive cervical resorption (ICR) can be challenging, depending on the extent of the defect and its location; the clinician should provide the patient with several treatment options and discuss the advantages and disadvantages of each treatment approach. A thorough clinical and radiographic examination should be done before treatment. This case report presents a case with Class III ICR where controlling the bleeding during treatment was achieved using a different approach than what is documented in the literature; the approach was effective in providing a dry field and isolating the root canal space until the root canal treatment was completed and the surgical repair was performed. The described technique can be used when it is not feasible to provide the surgical and nonsurgical treatment at the same appointment without compromising the treatment objectives.