Incorporation of Hydroxyapatite (HA) and Calcium Triphosphate (TCP) in the Epoxy Resin-Based Sealer

Objective This study aims to assess and compare the influence of hydroxyapatite (HA) and tricalcium phosphate (TCP) nanoparticles on a commercially available epoxy resinbased sealer, focusing on porosity and push-out bond strength. Materials and Methods This work was classified into a control group and two experimental groups. In each experimental group, the sealer was mixed with 2.5 wt.% of HA and TCP nanoparticles. Thirty extracted single-rooted teeth were utilized. After sectioning the crowns, the remaining roots of 15 teeth were used, up to 40 to 0.06, using a K3 rotary system. Smear layers were removed with 3 mL of 17% EDTA applied for 60 seconds. Then, the canals were irrigated with 3 mL of 2.25% NaOCl and 5 mL of distilled water. The strength of push-out bonds was tested via an Instron universal testing machine on a 2 mm section acquired from obturated canals. Data were assessed using one-way ANOVA and post hoc tests at a significance level of p < 0.05. Results A nonsignificant difference (p > 0.05) was evident when the three groups were crosschecked in terms of void volume and bond strength. Micro-CT evaluations revealed the lowest volume of voids to be 0.1152 mm3 (2.69%) for the HA group compared with the control group 0.1818 mm3 (3.9%) and the TCP group 0.2194 mm3 (4.33%). Mean bond strength values were 4.18 ± 1.77 MPa for group 1 (control), 4.19 ± 1.54 MPa for group 2 (HA 2.5%) and 3.76 ± 1.95 MPa for group 3 (TCP 2.5%). Groups 1 and 3 showed both cohesive and a mixed type of failure, while group 2 showed adhesive and a mixed type of bond failure. Conclusion Within the limitations of the study, incorporation of 2.5 wt% HA and TCP nanoparticles into AH Plus did not significantly affect the percentage volume of voids and the bond strength negatively.

Analysis of Vitamin D Receptor Gene Polymorphism in Chronic Periodontitis among Saudi Population

Objective Genetic and environmental factors have important roles in the development of periodontitis. We aimed to assess the relation of vitamin D receptor (VDR) ApaI and TaqI polymorphisms and the susceptibility of periodontitis in Saudi population in Makkah region. Materials and Methods In total, 86 unrelated patients with moderate-to-severe periodontitis and 86 controls were enrolled in this study. Evaluation of the periodontal state was performed by using plaque index, bleeding on probing, probing depth, and attachment loss. Extraction of genomic DNA from peripheral blood and genotyping of VDR gene ApaI G/T (rs7975232) and TaqI T/C (rs731236) polymorphisms were performed by utilizing polymerase chain reaction and restriction digestion. Results There were statistically significant differences between both groups regarding the mean bleeding on probing, mean probing depth, mean plaque index, and the mean attachment level (p < 0.001) indicating that the matching based on the investigated groups was adequate. The examined populations were in Hardy-Weinberg equilibrium. Analysis of the genotype and allele frequencies of both VDR ApaI and TaqI single nucleotide polymorphisms revealed that they were statistically indifferent between the control group and the periodontitis subjects (p> 0.05). Conclusion These results suggested that VDR ApaI and TaqI polymorphisms might not be related to the susceptibility of periodontal disease in the Saudi subjects in Makkah region.

Do Orthodontists and Orthodontic Residents Perceive that Work-Life Balance and Work-Family Conflicts Affect Their Organizational Commitment?

Objectives Two of lives’ most important domains may be in conflict with each other. This study investigated the association between perceived work-life balance (WLB), work interference with family (WIF), family interference with work (FIW), and organizational commitment (OC) of Nigerian orthodontists and orthodontic residents. Materials and Methods Consultant orthodontists (n = 37) as well as orthodontics residents (n = 33) responded to an electronic questionnaire. Statistical Analysis Multivariate analysis of variance assessed significant differences among demographic and career features on WLB, WIF, and FIW. Spearman’s correlation coefficient and then multiple regression analysis examined relationships among perception of WLB, WIF, FIW, and OC. Results Perceived WLB and WIF had statistically significant negative correlation with OC among Nigerian orthodontic practitioners. However, the study finds a positive, but not statistically significant correlation of perception of FIW and OC. Conclusion Perceived WLB and WIF are significant contributors to levels of OC among Nigerian orthodontists and orthodontic residents. Multiple regression analysis identified a model that includes perceived WLB, WIF, and FIW that accounts for 16.7% of the variation in OC.

Evaluation of PhD Students’ and Endodontists’ Treatment Approaches during the COVID-19 Pandemic: A Questionnaire-Based Survey

Objectives This study aimed to evaluate endodontists’ treatment approaches during the novel coronavirus disease (COVID-19) pandemic. Materials and Methods Web-based 16-question survey was sent to members of the Turkish Endodontic Society via social media and email between May 5 to 25, 2020, to obtain information about the members’ demographic characteristics and treatment approaches of seven cases considering COVID-19. The cases represented different endodontic diseases such as symptomatic apical periodontitis, chronic apical periodontitis, acute apical abscess, asymptomatic and symptomatic cases required retreatment, third molar tooth with endodontic symptoms, and symptomatic irreversible pulpitis. Statistical Analysis Statistical analysis was performed using a Chi-square test. The statistical significance was set at α = 0.05. Results Of the 203 respondents, 65.5% were females and 34.5% were males, 62.6% were endodontists and 37.4% were PhD students, 68% worked at a university, 21.2% worked at private clinics, and 10.8% worked at public clinics. Frequency of going to work was mostly once a week (31%). Most commonly performed treatments were “acute apical abscess (32.2%)” and “symptomatic irreversible pulpitis (30.8%).” The respondents most frequently preferred “to prescribe antibiotics and/or painkillers and postpone the treatment” in cases 1 and 6, “to follow-up” in cases 2 and 5, “to extract the tooth” in case 4, and “to start endodontic treatment but postpone the treatment by placing antibacterial medicament into the root canals” in cases 3 and 7 (p < 0.05). Conclusion During a pandemic, the general treatment approach for endodontic emergencies should be to eliminate acute symptoms and minimize the risk of transmission.

Minocycline Hydrochloride as a Potential Adjuvant to Improve Osteoconductive and Osteoinductive Properties of Bone Substitutes in an Extra-Skeletal Bone Augmentation Model: Preliminary Observations in Rats

Objectives The present study was performed to determine if minocycline HCl could influence the behavior of deproteinized bovine bone mineral (DBBM) and bioactive glass (BG) particles when used as filler material for new bone generation in a guided bone augmentation model. Materials and Methods Two occlusive titanium caps were placed on the rat calvaria. One filled with BG particles, the second with DBBM particles, both previously mixed with blood (control). In minocycline HCl loaded groups (experimental), grafts were additionally placed into a minocycline solution. Samples were harvested after 4, 8, and 16 weeks. Half of the samples were embedded in methylmethacrylate for undecalcified histology and the other half was fixed, decalcified, and embedded in paraffin for classical histologic analysis. Results The control groups highlighted osteoconductive and osteoinductive responses associated to BG particles, as well as an osteoconductive reaction, in DBBM sections. The addition of minocycline HCl to BG particles had no measurable influence on the result. In minocycline HCl loaded DBBM sections; however, areas of spontaneous ossification could be observed after 8 and 16 weeks. Conclusion Our observations suggest that minocycline HCl may add some osteoinductive properties to DBBM within the limitations of this study design. Further investigations are needed to refine the present results.

Effect of Polymerization Time and Shade on the Depth of Cure of Nano-Hybrid Resin Composites

Objective The effect of polymerization time and resin shade on the depth of cure (DOC) of two nano-hybrid resin composites (Filtek Z250 XT and IPS Empress Direct) was evaluated and compared. Materials and Methods Sixty specimens were prepared from two shades (A1 and A3) of the resin composites. The specimens were allocated into two groups that were further divided into three subgroups depending on the polymerization time (20, 40, and 60 sec; n = 5). After that, the DOC was evaluated by calculating the polymerized part of the specimen’s thickness to the nearest (0.01 mm) using a high-accuracy micrometer. Each specimen was measured three times, and the corresponding mean reading (in mm) was divided by two to obtain the DOC. The data were analyzed using SPSS software, version 20. Descriptive statistics followed by three-way analysis of variance was applied. Multiple comparisons were made using Scheffe post hoc tests (α = 0.05). Results Filtek Z250 XT-A1-60sec presented with the greatest DOC (7.42 ± 0.47 mm), and the lowest DOC was obtained with IPS Empress-A3-20sec (2.31 ± 0.21 mm). The mean DOC of Filtek Z250 XT and IPS Empress Direct resin composites were 6.18 mm and 3.59 mm, respectively. Statistically significant (p < 0.05) difference was observed between the resin composites. The interaction between independent factors, namely composites, resin shade, and polymerization time, revealed that interaction between them contributed significantly to the DOC (p ≤0.05). However, the interaction between resin shade and the polymerization time was insignificant (p = 0.148). Conclusion Filtek Z250 XT demonstrated greater DOC than IPS Empress Direct resin composite. An increase in polymerization time significantly enhanced the DOC of the resin composites irrespective of the resin shade. Regardless of the resin composite tested, DOC was lower for darker shades (A3).

Root Canal Morphology of Maxillary First and Second Molars in a Qatari Population: A Cone-Beam Computed Tomography Study

Objective The purpose of this study was to evaluate the number of roots and canal configuration of maxillary first and second molars in Qatari population. Materials and Methods A total of 544 cone-beam computed tomography (CBCT) records of Qatari patients were included in this study. The CBCT images were reviewed by two endodontists. The age, sex, bilateral symmetry, root number, and canal configuration according to Vertucci were tabulated. Results About 97.5% maxillary first molars had three roots and 2.5% had two roots. Maxillary second molar showed 88.2% three roots, 7.3% two roots, 3.3% single root, and 1.2% four roots. For maxillary first molars, the most common Vertucci classifications for the mesiobuccal root were type IV (2-2, 35.9%) and type II (2-1, 21.1%). For maxillary second molars, the most common Vertucci classifications for the mesiobuccal root were type IV (2-2, 27%), type III (1-2-1, 21.3%), type I (1, 19.6%), and type II (2-1, 18.9%). In maxillary first molar, 53.1% right is different from the left and in maxillary second molars, 60.2% right is different from the left. Conclusions In Qatari population, three roots are common in maxillary molars. Mesiobuccal root of maxillary first molars is predominant with Vertucci type IV (2-2) and type II (2-1). Maxillary second molars showed variable Vertucci classification. High bilateral asymmetry was found in canal configuration of the same individuals that should be considered during root canal treatment of two opposite molars.

Naturally Derived Photoinitiators for Dental and Biomaterials Applications

Biocompatibility of materials used in dental and biomaterials applications is very important and depends on the components of these materials. Photopolymerized materials for dental and biomaterials applications have been progressively used since the 1970s. One of the crucial components in these materials is the photoinitiator (PI) that initiates the polymerization reaction. Synthetic PIs are the most commonly used types, but owing to their drawbacks such as cytotoxicity, insolubility in water, and high cost, research on naturally derived (bio-sourced) PIs is growing, to find an alternative to these synthetic types, especially in the growing field of three-dimensional (3D) printing and bioprinting of biomaterials for tissue engineering applications. Naturally derived PIs are biocompatible, highly water-soluble, and abundant. Naturally derived PIs have been used to prepare experimental dentine bonding agents, dentine primers, photo-crosslinked hydrogels for tissue engineering applications, antibacterial coatings, guided tissue regeneration membranes, and 3D printed biomaterials. An electronic search was done using MEDLINE/PubMed and Scopus databases using the keywords naturally derived, bio-sourced, PIs, dental, biomaterials, 3D printing, and 3D bioprinting, to review potential naturally derived PIs for dental and biomaterials applications. There are a variety of naturally derived PIs with various colors and absorption spectra to choose from, according to the intended application. Most of naturally derived PIs can be used with modern conventional dental light curing units, making them applicable for experimental studies for potential dental and biomaterials applications. Due to their biocompatibility and availability it is expected that in the upcoming years, research on naturally derived PIs and their dental and biomaterials applications will increase especially in the growing field of 3D bioprinting in which cell viability is essential; thus this review was done.

Periodontal Experimental Research

Periodontal research in the last few decades has shown discoveries and inventions related to techniques and material science. In the first part of the review, we have discussed the problems and difficulties faced in epidemiological research. In the second part, an overview of the difficulties encountered in experimental periodontal research has been discussed.

Perception of Medication-related Osteonecrosis of the Jaws among Iraqi Medical Specialists

Objective Osteonecrosis of the jaws is the adverse effect of antiresorptive and antiangiogenic agents, which is termed as medication-related osteonecrosis of the jaws (MRONJ). This complication, which is prominent and growing, is seen in the oral and maxillofacial region. This cross-sectional survey aimed to evaluate MRONJ awareness among Iraqi medical specialists. Materials and Methods A questionnaire-based survey was performed on medical specialists practicing general surgery, urology, orthopedics, rheumatology, and oncology. The questionnaire consisted of four questions regarding drug prescription, patients’ preparation before drug administration, in addition to awareness and knowledge about MRONJ. Results Among 132 specialists, 57% did not prescribe such drugs. A significant difference existed among groups regarding dental referral, and MRONJ awareness and knowledge. The highest rates were seen in the oncologist group. Conclusions Improvement of MRONJ perception and knowledge among medical specialists, besides implementation of dental referral, are essential in the prevention, diagnosis and treatment of MRONJ.