Journal of dentistry (Shiraz, Iran)最新文献

Background: Taurodontic teeth are known for complex root canal configurations, including C-shaped canals, further complicating dental procedures. Given the diagnostic and therapeutic challenges posed by taurodontism, understanding its prevalence and its relationship with canal morphology, especially through modern imaging techniques, is essential for improving clinical outcomes.

Purpose: This study aimed to investigate taurodontism and explore its association with C-shaped canals using CBCT images from 2020 to 2024. This enhanced imaging technology will provide a more detailed view than panoramic imaging.

Materials and method: This retrospective analytical study examined 700 jaws (350 lower and 350 upper), chosen through simple random sampling from CBCT images originally taken for therapeutic purposes in individuals aged 14 and above. Teeth were evaluated based on Shifman and Chanannel's criteria and categorized as hypotaurodontism, mesotaurodontism, or hypertaurodontism according to morphology. Additionally, the study investigated the presence and types of C-shaped canals in the teeth.

Results: In this study, the median age of the cases was 40 years, with 63.7% female and 36.3% male. The overall prevalence of taurodontism in teeth, regardless of jaw and tooth type, was 9%. Taurodontism was predominantly bilateral (84.7%) and mild (75%). It was significantly more common in maxillary teeth than mandibular teeth (p< 0.001), with the highest prevalence in the second and first maxillary molar teeth. Sex did not show a significant association with taurodontism prevalence (p= 0.208), type (p= 0.371), laterality (p= 0.627), as well as the involved tooth. Additionally, the prevalence of C-shaped canals was 15.4%, and it was significantly higher in individuals with taurodontism (p< 0.001).

Conclusion: Taurodontism was found to be relatively common in the patients studied, with a high prevalence. Due to the challenging nature of treating taurodontic teeth, practitioners should be aware of the potential presence of C-shaped canals when encountering taurodontism in radiographic images.

Bioceramics (BCs) have gained significant popularity in various dental applications, including regenerative procedures, apexification, and root-end filling obturation, due to their remarkable characteristics, such as biocompatibility, sealing ability, and bioactivity. Despite their versatile applications, these materials possess few drawbacks, including extended setting time, discoloration, granular consistency, and complex handling. It is imperative to consider reformulating these materials in order to improve their properties and meet their special needs. Additionally, further research is needed to ensure their safety for clinical use. In recent decades, modifications in mineral trioxide aggregate (MTA) composition and properties have been a topic of research interest. This study aims to review recent advancements in modifying the chemical, mechanical, and biological properties of this versatile material and introduce some new commercial products to help practitioners select their required material wisely and assist researchers in planning future investigations.

Background: Childhood obesity is an increasing global health concern associated with both systemic and oral complications. While studies suggest links between body mass index (BMI) and oral health markers, these relationships remain poorly defined.

Purpose: This study evaluated the association between salivary microbial/fungal populations, salivary acidity, and obesity in children.

Materials and method: In this cross-sectional descriptive study (2021-2022), 90 children aged 8-12 from public schools in Qom, Iran, were categorized into three groups based on BMI: 30 children with normal weight, 30 overweight children, and 30 obese children. Demographic information, including parental education and occupation, was recorded. Unstimulated saliva samples were collected using the passive drooling method. A total of 0.5 ml of saliva was mixed with 5 ml of phosphate-buffered saline (PBS) and homogenized thoroughly by using a shaker. Microbiological analysis involved quantifying colonies of Streptococcus mutans, Lactobacillus, and Candida albicans and measuring salivary pH using a calibrated pH meter. Data were analyzed using appropriate statistical tests with significance set at p Value< 0.05.

Results: No significant relationship was found between childhood obesity and parental education (father's p= 0.051, mother's p= 0.862) or occupation (father's p= 0.224, mother's p= 0.893). Salivary pH did not differ significantly between weight groups (p= 0.639). Overweight children had lower Lactobacillus levels (p= 0.857), and obese children had higher Streptococcus mutans levels (p= 0.777); though neither correlated significantly with BMI. Candida albicans colonies showed a significant negative correlation with childhood obesity (p= 0.046). Significant associations were also observed between Streptococcus mutans (p= 0.046) and Lactobacillus (p= 0.002) levels with Candida albicans levels.

Conclusion: Although oral bacterial levels did not differ significantly across weight groups, fungal species, particularly Candida albicans, varied significantly. A negative association between obesity and Candida albicans counts suggests that obesity may impact the salivary microbial ecosystem, highlighting the need for further research into its systemic and oral health implications.

Background: Remineralizing early enamel lesions in primary dentition remain a significant challenge in dentistry, requiring innovative approaches to enhance enamel repair.

Purpose: This study aimed to evaluate the efficacy of a commercially available nanohydroxyapatite paste (Nano P), alone and in combination with air dielectric barrier discharge cold atmospheric plasma (CAP) and a 940-nm diode laser, on enamel remineralization.

Materials and method: In this in vitro study, 105 intact anterior primary teeth were randomly assigned into one control and six experimental groups: (I) control, (II) Fluoride varnish, (III) Nano P, (IV) Nano P + dye + laser, (V) Nano P + laser, (VI) CAP, and (VII) Nano P + CAP. Caries-like lesions were induced by demineralization. Microhardness was evaluated before and after demineralization and 4 weeks post-remineralization with pH cycling. Data analysis was conducted using one-way ANOVA (α=.05) and Tamhane's Post-Hoc test, with effect sizes determined by Cohen's d test and Hedges' g correction. The percentage of recovery of the enamel microhardness was calculated.

Results: Initial and secondary microhardness were similar across groups (p Value >.05). Post-remineralization, significant differences were observed (p< 0.05), with the highest microhardness in the Nano P+ laser group, followed by Nano P+ dye+ laser, Nano P+ CAP, Nano P, fluoride varnish, CAP, and the control. Pairwise comparisons showed significant differences between all pairs except Nano P+ laser and Nano P+ dye + laser (p= 0.7, Effect size=0.4).

Conclusion: Nano P combined with a laser, followed by Nano P with plasma, and Nano P alone significantly increased microhardness more than fluoride or plasma, suggesting these combinations as effective alternatives for enamel remineralization in primary teeth.

Background: Surgical removal of impacted mandibular wisdom teeth may be associated with postoperative complications such as infection, bleeding, edema, pain, ecchymosis and trismus. It seems that the number of sutures and the duration of surgery for impacted wisdom teeth are among the factors affecting the aforementioned complications.

Purpose: This study aimed to compare single-suture versus multiple-suture techniques regarding postoperative pain, trismus, edema, ecchymosis, and operating time in surgical removal of impacted mandibular wisdom teeth by envelope flap surgery.

Materials and method: This double-blind split-mouth randomized controlled clinical trial was conducted on 30 patients requiring bilateral surgical extraction of impacted wisdom teeth with the same level of impaction through an envelope flap. In each patient, wisdom teeth of one randomly selected quadrant was extracted through an envelope flap and single-suture technique (experimental group) while the wisdom teeth of the other quadrant was extracted through an envelope flap by multiple-suture technique (control group). The two groups were compared regarding operative time, and also pain score, trismus (mouth opening), edema, and ecchymosis at 1, 3 and 7 days postoperatively using paired t-test (alpha= 0.05).

Results: The two groups had no significant difference in pain score, edema, and ecchymosis at any time point (p> 0.05). The operative time (p= 0.005) was significantly longer, and mouth opening at 1, 3 and 7 days postoperatively (p< 0.05) was significantly smaller in the multiple-suture group.

Conclusion: In the present study, postoperative trismus was significantly lower in the single-suture group than multiple-suture group, and the multiple-suture group had significantly longer operative time. Thus, single-suture technique appears to be superior to multiple-suture technique, and may be suggested for surgical removal of impacted mandibular wisdom teeth.

Background: Hybrid odontogenic lesions (HOLs) show combined microscopic features of two or more recognized odontogenic cysts and neoplasms, occurring in the same primary location. These lesions are uncommon and there is limited information on the clinical and microscopic features of such lesions.

Purpose: We aimed to assess the frequency and types of HOLs admitted to a main oral pathology center in Iran in 30 years.

Materials and method: In this retrospective observational study, the archives of the Oral and Maxillofacial Pathology Department of Shahid Beheshti University of Medical Sciences from 1993 to 2022 were reviewed, and cases diagnosed with odontogenic lesions were selected. All microscopic slides were screened and cases of the HOLs were extracted.

Results: Over 30 years, a total of 1767 cases (composed of 1264 cysts and 503 tumors) were found to be odontogenic lesions, of which 19 cases (1.07%) were classified as HOLs. The mean±SD and median age of patients were 22.57±13.19 and 15 years, respectively. The most common HOL was dentigerous cyst/odontoma (42.10%) followed by calcifying odontogenic cyst/odontoma (10.52%) and central odontogenic fibroma/central giant cell granuloma (10.52%). About 68.42% of the lesions were associated with impacted teeth. Radiographically, most of the HOLs had a mixed internal structure (68.42%) and were unilocular (73.68%). Most of the lesions showed painless expansion (63.15%). All cases were managed with surgical treatment alone, most of which had conservative surgery (enucleation of the lesion) (88.88%).

Conclusion: HOLs are rare and show a wide variety of histopathologic features. HOLs generally showed the highest frequency in the second decade of life. Awareness of these microscopic patterns can lead to proper diagnosis and management.

Background: The elimination of pathogenic microorganisms is crucial in endodontic treatments, as Enterococcus Faecalis is involved in the majority of endodontic failures. This bacterium is known for its resilience and ability to persist within the root canal system, often leading to treatment complications.

Purpose: The aim of this study was to compare the antibacterial efficiency of three different irrigation methods including passive ultrasonic, XP Endofinisher file, and Laser Diode 810 nm in infected roots with Enterococcus Faecalis (E.faecalis) biofilm.

Materials and method: In this experimental study, 48 anterior single-canal teeth were enrolled. After cutting their crowns, the teeth were cultured with E.faecalis and then randomly divided into four groups. Following preparation through the rotary system up to F4 at the working length, passive ultrasonic irrigation (Ultra X) was used inside the root canal in the first group. In the second group of the study, the XP Endofinisher file was applied to activate the irrigation solution, while in the third group, the Laser Diode 810 nm was used. The fourth group served as the control group and did not utilize any irrigation. The irrigation solution employed across all groups consisted of 1ml of 5.25% sodium hypochlorite (NaOCl), followed by a final irrigation with 5ml of 17% ethylenediaminetetraacetic acid (EDTA), 5ml of 5.25% NaOCl, and 5ml of sterile saline. After canal irrigation and sampling, bacterial colony counting was conducted, and the data were recorded. If the data were normally distributed, a variance test analysis was used; otherwise, the non-parametric Kruskal-Wallis test was applied. The tests were performed at a 5% significance level using SPSS software version 24.

Results: The reduction in the number of bacterial colonies was significantly greater in all three methods compared to the control group. The obtained data revealed that the antibacterial effect of Laser 810 nm was considerably (p< 0.05) higher than the other two groups and reduction in the number of colonies in Ultra X group was remarkably (p< 0.05) greater than the XP Endofinisher file group.

Conclusion: All three mentioned methods were effective in reducing the number of bacteria in endodontic treatments. Notably, the antibacterial efficiency of the Laser Diode 810 nm was significantly greater than that of the other two methods.

Background: Each patient may have a different idea of a beautiful smile. Also, during treatment, periodontists, restorative dentists and general dentists should be aware that their personal views on the beauty of a smile and their degree of sensitivity in the perception of beauty changes may differ, and this difference may affect the treatment process.

Purpose: This research seeks to evaluate how alterations in the shape and position of the gingival margin in maxillary anterior teeth influence the perception of smile aesthetics among different groups including periodontists, restorative dentists, general dentists, and non-professionals.

Materials and method: This cross-sectional study was conducted on 60 raters in four groups (n= 15) of periodontists, restorative dentists, general dentists, and non-professionals. The raters received 10 photographs including one original and 9 altered images, and they were asked to rate them regarding smile aesthetics. Data were analyzed by the Kruskal-Wallis, Fisher's exact, and t-test (alpha=0.05).

Results: All four rater groups gave the highest score to the original image and the lowest score to the asymmetrical changes on shape and position of the gingival zenith; the statistical difference in this regard was significant in the group of periodontists, restorative dentists, and general dentists (p< 0.05) but not in non-professionals (p Value> 0.05). Males were more sensitive than females in the detection of changes in shape and position of the gingival margin; however, the statistical difference was only significant for images showing an asymmetrical change on the right or left side (p< 0.05).

Conclusion: A significant difference in opinion was seen among periodontists, restorative dentists, and general dentists regarding the effect of the shape and position of the gingival margin of maxillary anterior teeth on the perception of smile aesthetics, highlighting the need to reach an interdisciplinary consensus prior to gingivectomy and aesthetic crown lengthening procedures.

While traumatic injuries in the young permanent dentition are frequent, root fractures are relatively rare, particularly in immature teeth. This study reports the case of a 7-year-old boy who fell off a bicycle. Radiographic examination showed an immature right upper central incisor with fractures in the middle and along the root in an oblique and horizontal direction. Furthermore, there was an extrusion of the coronal segment from its original position. At the first appointment, the right central incisor was repositioned, and a semi-rigid splint was applied for four weeks. The patient was examined periodically for the following two years. After two months, the injured tooth was asymptomatic, with a reduction in probing depth from 8 mm to 2 mm along the tooth surface and a physiologic mobility. Although the injured tooth responded to the electric pulp test after nine months, it had no response to the cold test even after two years. The injured tooth showed continued root maturation of both coronal and apical fragments, although metamorphosis calcification and root canal narrowing were observed in conjunction with mild yellow crown discoloration. This report highlights the ability of Hertwig's epithelial root sheath and immature pulp to continue root development in fractured immature teeth.

Background: Relapse is acknowledged as a substantial failure after orthodontic correction. As a biomarker of bone formation, alkaline phosphatase (ALP) levels will decline in compressive sites during relapse subsequent to orthodontic tooth displacement. Manipulating alveolar bone remodeling to elevate ALP levels using novel biomaterial is presently regarded as one of the innovative approaches to avert relapse effectively.

Purpose: This study aimed to evaluate the effect of carbonated hydroxyapatite (CHA)-statin nanoemulsion on ALP levels in relapsed rats.

Materials and method: In this in vivo study, forty-eight (n= 48) rats were divided into four groups: control, CHA, statin, and CHA-statin, with 12 rats in each group. A 30g mesial tract-ion was applied for seven days using a closed-coil spring extending from the first maxillary molar to the maxillary incisor. Over seven days, CHA, statin hydrogel, and nanoemulsion CHA-statin were injected every three days to preserve the repositioned teeth. Removing the appliances allowed for relapse to occur. ALP levels were assessed using an enzyme-linked immunosorbent assay on days 0, 1, 7, and 14 after debonding. The acquired data was analyzed using analysis of variance and a post hoc Tukey's test with a significance level of p< 0.05.

Results: The average ALP levels between the groups did not differ significantly (p> 0.05) on days 0 and 1 of relapse. The mean values were highest in the CHA-statin nanoemulsion group. The control group exhibited the lowest average ALP levels on day 7 of the relapse phase, followed by Group CHA, Group statin (St), and Group CHA-St, with a significant difference (p< 0.05). On day 14, the CHA-St group had the highest average ALP levels (p< 0.05), while the CHA and St groups did not differ (p> 0.05).

Conclusion: The results indicated that nanoemulsion CHA-statin could elevate ALP levels during orthodontic relapse.