Journal of Dentistry
Year:2021 | Volume:22 | Issue:2|Papers Count:12

Statement of the Problem: Treating zygomaticomaxillary complex fractures (ZMC Fx) can result in postoperative complications that should be minimized by choosing the best surgical approach. Purpose: This study compared incidence rates of some common postoperative complications with emphasis on ectropion (an outward curling of the lower eyelid) and entropion (an inward curling of the lower eyelid) occurring with transconjunctival or subciliary approaches for the treatment of ZMC fractures. Materials and Method: This prospective study enrolled 80 patients with ZMC Fx who had been surgically treated. Patients were visited within one month and five months postoperative-ly by the same surgeon. An information checklist was completed for each patient for clinical assessment of postoperative complications. Results: There was no significant difference between the two groups in the type of trauma (simple or comminuted) (p= 0. 1) or the frequency of ectropion and entropion one month and five months postoperatively (p> 0. 05). The same results were observed for history of massage under the eye or around the field of surgery (p= 0. 151), scleral show (p= 0. 414), history of post-surgical epiphora (overflow of tears and accumulation of tear) (p= 0. 059), duration of the use of suspension/frost sutures (used to prevent eyelid distortion secondary to wound injury applied at the skin inferior to the incision to help elevate the lid) (p= 0. 057), and the use of porex (an alloplastic material over the defect in the orbital floor) (p= 0. 91). Conclusion: There was no significant difference between the transconjunctival approach and the subciliary approach in terms of common postoperative complications such as ectropion and entropion.

Statement of the Problem: Alteration in salivary composition and its effect on the oral cavity in diabetic child patients remains equivocal. Purpose: This study was performed to assess the relationship between salivary factors and gingival status in children with type-1 diabetes mellitus (DM). Materials and Method: In this cross-sectional study, 120 subjects aged 6-16 years (60 well-controlled and poorly-controlled diabetics and 60 healthy individuals) were examined to determine the gingival index (GI) and plaque index (PI). The unstimulated saliva samples were collected to measure the salivary triglyceride, cholesterol, albumin, α-amylase, total protein levels by the laboratory kits. Total antioxidant capacity and the free radicals scav-enger index were measured by the Ferric Reducing Ability Of Plasma (FRAP) and 1, 1-Diphenyl-2-picryl-hydrazyl (DPPH) assays, respectively. Data were analyzed by parametric and non-parametric, Pearson correlation, and t tests at a 5% error level. Results: GI of diabetics was significantly higher than that of healthy individuals (1. 51± 0. 71 and 0. 9± 0. 81, respectively, p< 0. 001). No significant difference was found between the PI of diabetics compared to healthy volunteers (1. 59± 0. 69, 1. 63± 0. 74, respectively). The levels of salivary triglyceride and cholesterol, albumin and total proteins in healthy subjects were significantly higher than that in people with DM (p< 0. 001). A significantly more salivary α-amylase activity was found in diabetics compared to non-diabetics (p< 0. 001). No significant differences were found between diabetic and non-diabetic subjects in terms of DPPH (95. 5, 95. 9%, respectively) and FRAP (9. 77± 0. 13, 9. 78± 0. 12 (μ mol/mL), respec-tively). Conclusion: More gingival inflammation and salivary α-amylase activity and lower level of salivary lipids, albumin, and total proteins were found in diabetic patients, but there was no association between the level of lipids, proteins, and the total antioxidant capacity of saliva with periodontal health indicators in patients with DM and healthy individuals.

Statement of the Problem: A rise in pH and the presence of calcium ions play an important role in prevention or management of external root resorption. Purpose: This study assessed the long-term pH alterations in the periradicular area following the application of calcium hydroxide (CH) and mineral trioxide aggregate (MTA) intracanal medicaments. Materials and Method: This in vitro, experimental study evaluated 45 single-canal extracted human teeth. After decoronation and root canal instrumentation, defects (3×3×1mm) were created in the middle third of the roots. Following smear layer re-moval, the root surface (except for the defect) was sealed with nail varnish. Five teeth served as negative controls and were filled with distilled water. The remaining 40 teeth were randomly divided into two groups (n=20) for application of MTA and CH as intr-acanal medicaments. Periapical radiographs were obtained to ensure optimal quality of obturation. After coronal sealing with glass ionomer, the teeth were incubated at 37° C, and their pH was measured at 1 and 2 weeks, and 1 and 3 months, using a pH-meter. Data were analyzed using one-way ANOVA, Tukey’ s test and Bonferroni adjustment. Results: The mean pH was significantly higher in CH group at 1 and 2 weeks (p< 0. 01) but no difference was noted at 1 and 3 months (p= 0. 52). The mean pH in both groups was significantly higher at 2 weeks compared with other time points (p< 0. 05). Conclusion: CH may be preferred for use in the first weeks following the initiation of root resorption to provide a high pH. MTA can be later applied to maintain the high pH for a longer period of time without the need for medicament exchange.

Statement of the Problem: Different materials have been used to repair root perforations, the most successful of which is mineral trioxide aggregate (MTA). It is technically difficult to use MTA for perforation repair. Recently, some bio-ceramic sealers such as Endoseal MTA were introduced to repair the perforation site during root filling, which decreases the technical difficulty of this procedure. Purpose: The aim of this study was to compare the bacterial microleakage of Pro-Root MTA and Endoseal MTA sealer in root perforation repair. Materials and Method: This in vitro experimental study evaluated 40 extracted canine teeth. After root canal cleaning and shaping, a root perforation was artificially created at 7 mm below the cementoenamel junction. The teeth were then randomly divided into two ex-perimental groups (n=18) of Pro-Root MTA and Endoseal MTA, and two positive and nega-tive control groups (n=2). Perforation sealing and root canal filling were performed in the two experimental groups according to the manufacturers’ instructions. After sterilization of the whole system with gamma ray, microleakage was tested using a double-chamber model. Data regarding the presence/absence of microleakage were reported after 35 days. The data were analyzed by SPSS software using the Chi-square test. Results: There was no significant difference between the two experimental groups regarding bacterial microleakage (p> 0. 05). Conclusion: Under the conditions of this study, it can be concluded that the sealing ability of perforation repair with Endoseal MTA Sealer and Pro-Root MTA was comparable.

Statement of the Problem: The degree of asymmetry perception of dental and medical practitioners is influenced by several factors. The perceived asymmetry affect the treatment plan design. Purpose: The aim of the present study was to investigate the consistency of facial asym-metry and identify the amounts of transverse asymmetry that can be regarded as normal and might need correction. Materials and Method: In this cross-sectional descriptive study, three-dimensional (3D) images of a man and a women volunteer were obtained. Then transverse changes were ap-plied by ZBrush software so that for each volunteer, seven 3D images of their face with varying degrees of facial transverse asymmetry were created. Then, the images were dis-played to four groups of observers including layperson, general dentists, orthodontists, and maxillofacial surgeons. Finally, the consistency of the perception of these four groups of observers with the different degrees of facial asymmetry was compared. Results: Fourteen photographic samples were evaluated and ranked by 80 observers in four groups. The consistency of the perception of the facial transverse asymmetry was equal to 33%, which indicated a lack of consistency. Conclusion: According to the findings of this study, there was no consistency between the groups. The perception of dental professionals and ordinary people regarding the severity of transverse facial asymmetry seems to be inconsistent.

Statement of the Problem: Dental caries is the most common chronic childhood disorders throughout the world. The dmft (decayed, missing, and filled primary teeth) and DMFT (decayed, missing, and filled permanent teeth) are some of the most important epidemiologi-cal indices in dentistry. Evaluation of these two indicators in the population can help in fu-ture planning of healthcare programs to improve oral health status. Purpose: The aim of this study was to evaluate these indicators and the related factors in first-grade primary school students in Rafsanjan urban area to determine their present status, which might be helpful for future health care planning. Materials and Method: In this cross-sectional study, DMFT index of first permanent molar and dmft were evaluated by census method on 2031 first-grade primary school students in Rafsanjan urban area in 2018 (May-June). Dental examination was done using a mirror and probe under natural light according to World Health Organization criteria. The data were then analyzed using independent two-sample t-test, one-way ANOVA, Tukey's multiple comparisons test, Kolmogorov-Smirnov nonparametric test and Leven's test in SPSS version 21 software. Results: The mean and standard deviation of dmft index and DMFT index of first permanent molar were 6. 37 ± 3. 40 and 0. 30 ± 0. 72, respectively. The proportion of caries free students was 4. 1%. A significant association was found between the values of these indices and school type, the level of education of parents, parental occupation, family size, and frequen-cy of brushing and the use of floss (p < 0. 05). However, there was no significant association between these two indices with gender (p= 0. 347 and p= 0. 593, respectively). Conclusion: The results of this study showed high prevalence of caries in first-grade prima-ry school students in Rafsanjan. Therefore, to improve this situation, more attention is need-ed for proper oral health program planning and education of families concerning oral hy-giene and dental preventive measures.

Statement of the Problem: Various species of candida contribute to oral candidiasis. It is the time to shift from conventional rigid antimicrobial therapies to more patient specific and safer ones. Purpose: The present study aimed to investigate antifungal effects of photodynamic therapy (PDT) using Indocyanine green as photosensitizer and low-power laser irradiation on the viability of candida albicans, candida tropicalis, candida glabrata and candida krusei, and to compare it with Nystatin as the conventional treatment. Materials and Method: In this in vitro study, 0. 5 McFarland suspensions of candida's spe-cies were prepared (n=50, each). Each strain was then divided into five groups of 10 samples each, according to the following experimental interventions: (1) Nystatin, (2) photodynamic therapy: laser irradiation (wavelength= 808 nm, power= 100 mW, energy density= 10 J/cm2, exposure duration= 100 s) in the presence of the photosensitizer, (3) laser irradiation alone, (4) treatment with the PS alone and (5-control: no exposure to laser light or photosensitizer. Next, serial dilutions were prepared and seeded onto Sabouraud dextrose agar. The colonies were counted, and the values of log (CFU/ml) were analyzed by variance and the Tamhan test (p< 0. 05). Results: Photodynamic therapy mediated indocyanine green is significantly effective in reducing the number of CFU/ml of all species of candida tested, compared to control group (p<. 001). Nystatin, laser irradiation and photodynamic therapy, with respectively decreasing potency, have considerably reduced the number of candida's colonies in all four bacterial strains (p<. 05). Photosensitizer alone, showed impressive antimicrobial potency against all species of candida except candida albicans, in comparison to control group. Conclusion: It seems that laser therapy alone is more powerful than photodynamic therapy mediated indocyanine green; however, conventional treatment has still the top antimicrobial efficacy towards all candida species.

Statement of the Problem: An attractive smile and white teeth give self-confidence and provide impression of health, which help individuals for social and interpersonal success. Increasing demand for tooth bleaching and lack of relevant information on the other hand, necessitate a new investigation to assess the knowledge of the students about dental bleach-ing in Kerman. Purpose: This study was designed to assess the overall knowledge of the students of Shahid Bahonar University of Kerman regarding dental bleaching and their tendency to perform it. Materials and Method: This cross-sectional study enrolled 384 students who were selected by simple random sampling. A valid and reliable self-administered researcher-made ques-tionnaire was employed to collect data about demographic information, health behavior, tooth bleaching, and the tendency to perform. This tool contained 8 questions with the focus on the knowledge of dental bleaching. Data were analyzed by using SPSS version 21 and regression analysis at a significant level of 0. 05. Results: Overall, 59. 55% of participants were male and 40. 45% were female students. Most likely, the source for gaining information was internet. In this regard, 29 individuals were dissatisfied with tooth color, 27 ones with the appearance of teeth, 13. 5% have done tooth bleaching, and 69% had tendency to do that. The preferred knowledge was about the differ-ence between scaling and root planning (SRP) and bleaching. There was no significant dif-ference between age, gender, and marital status variables with the knowledge of dental bleaching. Tooth color satisfaction increased the tendency to do bleaching about 1. 87 times. Conclusion: The study highlights that 69 % of the students had a tendency to do the bleach-ing, their knowledge was moderate, and there was no statistical relationship between knowledge, gender, and marital variables. Color variable had an overall positive effect on the tendency to do the bleaching.

Statement of the Problem: Retrieval of cement-retained implant-supported restorations is challenging in cases of screw loosening or periodontal problems. Purpose: The purpose of this study was to evaluate the effect of the screw access hole on the fracture resistance of zirconia-based cement-retained restorations with and without an access opening. Materials and Method: In this in vitro study thirty-three cement-retained implant-supported zirconia-based molar crowns were fabricated and divided into 3 groups (n=11). As the control group, group 1 consisted of conventional cement-retained crowns. Group 2 comprised conventional cement-retained crowns in which a hole was created in the location of the screw. Group 3 consisted of cement-retained crowns in which a ledge was created in the location of the screw access channel. The specimens were cemented to their abutments and their access openings were filled with composite resin. A compressive load was applied to the specimens using a universal testing machine until they fractured. The mean fracture resistance values of the samples were compared by using the one-way ANOVA and Tam-hane post-hoc test (a=0. 05). Results: The mean fracture resistance values were 1270. 18± 12. 67 N in group 1 (the control group), 960. 09± 210. 67 N in group 2 (conventional), and 1357. 81± 361. 68 N in group 3 (the special design). The fracture resistance value was higher in the special design group than that of the conventional design (p= 0. 018) and the fracture resistance value of the conventional design group was less than that of the control group (p= 0. 042). No statistically significant difference was detected between the control group and the special design group in fracture resistance values. Conclusion: Preparing a screw access hole in cement-retained implant-supported zirconia-based crowns decreased the fracture resistance of the restoration. Designing a ledge in the zirconia framework around the access hole may increase the fracture resistance of the resto-ration.

Statement of the Problem: Different materials can be used to reconstruct the core foundation in all-ceramic restorations. Bond strength of the core material to zirconia is an important fac-tor in long-term restoration success. Purpose: The aim of this study was to assess shear bond strength (SBS) of zirconia to four different core materials. Materials and Method: In this experimental in vitro study, 40 zirconia ceramic disks (10×3 mm) were prepared and divided to four groups based on core material. Cylinder shaped core specimens (3×4 mm) of non-precious gold alloy (NPG), zirconia ceramic, natural dentin, and composite resin were prepared and bonded perpendicularly to the zirconia disks using Gill-more Needle Apparatus and dual cure resin cement. All samples were thermocycled for 2000 cycles. To evaluate SBS, the specimens were tested by universal testing machine. Data were analyzed using Kruskal-Wallis test followed by Dunn's test with Bonferroni correction. Statis-tical significance was set at p< 0. 05. Results: The highest values for SBS were achieved in composite resin group (11. 58± 1. 74 MPa) followed by NPG (10. 32± 0. 94 MPa), zirconia (7. 3± 1. 11 MPa) and dentin group (6. 53± 0. 56 MPa). SBS in composite resin and NPG core materials were significantly higher than other core materials (p< 0. 05). Conclusion: Composite resin and NPG cores showed significant higher bond strength to zirconia in comparison to dentine and zirconia core materials.

Amongst odontogenic cysts, keratocystic odontogenic tumor (KOT) is a benign intra-osseous lesion, characterized by corrugated parakeratinized uniform stratified squamous epithelium, with potential for aggressive behavior and high tendency to recur. There are multiple treatment modalities for this cyst. Some surgeons prefer the conservative treat-ments such as marsupialization while the others prefer invasive treatments such as radical resection. The aim of this study was to present a case of KOT involving the right man-dibular premolar area with an impacted tooth in a 9-year-old boy treated by marsupializa-tion. The treatment resulted in eruption of the mandibular first premolar, and no signs of recurrence were observed after two years. Marsupialization was found to be an effective treatment in inducing the eruption of mandibular premolar associated with KOT in pre-adolescents and can be a reliable procedure to reduce recurrence tendency of KOT.

Dens invagination is a developmental anomaly that required specific treatment approaches. The invagination is truly negligible and enamel-lined for which the crown of the tooth is the only range and there is no extension on the level of the external amelocemental junction. A well ending surgical root canal treatment of an invaginated tooth applied a retrograde filling with MTA is concluded by this study. Periapical radiographic examination after 3 month and 6 year follow-up showed periapical healing with osseous formation.