Journal of Dental School
Volume:42 Issue: 4, Autumn 2024

 The latest generation of bonding agents is increasingly embraced and well-suited to fulfilling the requirements for durable restorations. This study aimed to assess microleakage levels of three self-etch adhesives (Clearfil SE (SE), Protect (PB), and Tri-S (TS) Bonds) in composite restorations at both occlusal and cervical borders, while considering the impact of water storage over different time intervals.

 Standard Class V cavities were prepared on buccal surfaces of 84 human premolars at the level of cementoenamel junction. The samples were randomly assigned to six groups (N=14). The corresponding bonding procedure in each group was completed, and the cavities were filled using Clearfil AP-X (Kuraray). Following thermocycling, the teeth were stored in deionized water within an incubator for 24-hour and 6-month intervals. Statistical analysis of microleakage data was conducted utilizing Kruskal-Wallis and Mann-Whitney U tests at p<0.05.

 Following a 24-hour interval, the level of microleakage at the occlusal surface was greater than the gingival surface for SE. No statistically significant differences were observed in microleakage at the occlusal and cervical borders after 24h of water storage for the PB and TS groups (P=0.51, 0.16). None of the SE and TS group samples showed leakage at the occlusal or cervical margins following a 6-month interval.

 Self-etching bonding agents indicated increased occlusal microleakage compared to the cervical margin microleakage.

This research sought to assess how fluoride varnish affects the shear bond strength (SBS) and adhesive remnant index (ARI) of ceramic brackets used in orthodontics.

Forty-eight freshly extracted premolars were randomly assigned to four groups(N=12each). Groups 1, 2, and 3 were treated with 5% sodium fluoride varnish 1, 7, and 14 days before ceramic bracket bonding, respectively. Group 4 as the control group received no pretreatment. The SBS of the brackets was measured using a Universal Testing Machine, while the adhesive remnant on the tooth surfaces wasassessed based on the ARI. The SBS and ARI were analyzed statistically using one-way ANOVA and Kruskal-Wallis tests, respectivelyat a significance level of 0.05.

Group 2 exhibited significantly lower SBS than that of group 1 (P=0.001). Group 1 displayed higher SBS than that of the control group (P=0.016). Additionally, group 3 exhibited greater SBS than group 2 (P=0.020). However, none of the groups showed an SBS lower than the standard value of 6 MPa. Regarding ARI, a significant difference was found only between Groups 1 and 2, with Group 2 showing a higher ARI than Group 1 (P=0.025).

The application of fluoride varnish at 1, 7, and 14 days prior to bonding ceramic brackets in orthodontics does not decrease SBS and does not significantly affect ARI compared to the control group

 One of the important indicators of growth and development is tooth eruption timing, which is influenced by various genetic and environmental factors. This study aimed to assess the relationship between different developmental parameters and eruption time of first primary tooth in infants aged 2-15 months.

 This cohort study was conducted on 873 infants aged 2-15 months in eastern health centers of Tehran, Iran. The height, weight, head circumference, breastfeeding/bottle-feeding practices, vitamin AD supplementation, and maternal age at birth of the infants were recorded. The eruption time of first primary tooth was recorded by monthly examination of infants at the health centers. The effects of qualitative and quantitative variables were analyzed using the independent t-test and Chi-square test, respectively. Linear regression analysis was performed to investigate the simultaneous effects of growth parameters on tooth eruption time at a significance level of 0.05.  

 The eruption time of first primary tooth had an inverse relationship with the weight (P<0.001), height (P=0.003), and head circumference (P=0.01) of the infants. The mean eruption time of the first primary tooth was 7.6 ± 1.7 months in normal birth weight infants (above 2500 g) and 9.7 ± 1.9 months in low birth weight infants (below 2500 g). There was no significant correlation between gender and the eruption time of the first primary tooth (P=0.16). However, the eruption time had significant relationships with maternal age, breastfeeding, and vitamin AD supplementation (P=0.001).

 higher birth weight, height, and head circumference, as well as breastfeeding and receiving vitamin AD supplements are correlated with earlier eruption of first primary tooth.

This study aimed to compare the effects of requirement-based and test-based formative assessment methods on pre-clinical endodontic competence and performance of dental students.

This interventional field study was conducted on dental students of Shahid Beheshti Dental School in the first and second semesters of 2021 academic year (third-year students), taking practical basic endodontics 1. After receiving theoretical instructions and practical demonstrations, the students in both groups were asked to perform root canal therapy for extracted maxillary anterior and mandibular/maxillary canine teeth as part of their requirement. Their errors were assessed and recorded by two calibratedinstructors. Next, group 1 students performed root canal therapy for mandibular incisors and premolars as their requirement and returned the treated teeth on a specific date every 3 weeks. Group 2 students did not have a specific requirement and only participated in an examination which included endodontic treatment of the same group of teeth treated by group 1 students at the same designated dates. The treated teeth were assessed by instructors for errors. A final examination was held at the end of the semester for both groups. The two groups were compared by independent t-test, ANCOVA, Pearson Chi-square, and Mann-Whitney tests (alpha=0.05).

No significant difference was found between the two groups in access cavity preparation, root canal instrumentation, or obturation (P>0.05).

Requirement-based and test-based formative assessment methods had similar effects on pre-clinical endodontic competence and performance of dental students

This study aimedto evaluate the effect of warm air solvent evaporation on microtensile bond strength of composite restorations bonded with fifth-generation adhesive systems.

Twenty-four sound human molars were randomly assigned into two groups according to the type of bonding adhesive used:Adper Single Bond (3M ESPE, USA) or Solobond M (VOCO, Germany)(N= 12). Subsequently, each group was randomly dividedinto three subgroups according to the solventevaporation time (0, 5, and 20 minutes). Composite build-ups were conducted incrementally on the dentin substrate fixed in a circular mold. Micro-tensile bond strength evaluation was conducted using the Isomet microtensile machine.Statistical analysiswasperformed usingone-way ANOVA, Tukey’s, and Student’s t-testat p<0.05.

At 20 minutes, Maximum and minimum microtensile bond strength were observed in Adper single bond and Solobond M, respectively.The mean microtensile bond strength of Adper single bond and Solobond M adhesives during 20 minutes of solvent evaporation weresignificantlydifferent(p < 0.05).

In both ethanol and water-based adhesives, increasing the solvent evaporation time enhancedthe microtensilebond strength. In contrast, in acetone-based adhesives, the optimum amount of solvent with other componentsmust be present in the bonding solution to maintain bonds

This study aimed to investigate the effect of propolis-based mouthwash on the gingival parameters of generalized chronic gingivitiscasesin a randomized controlled clinical trial.

A total number of 69patients with generalized chronic gingivitis were randomly assignedinto three groups(N=23): propolis, chlorhexidine, or placebo mouthwash. The gingival and bleeding indices were evaluated before and after two weeks of mouthwash use.Data analyses were performed usingKruskal-Wallis test, one-way analysis of variance, and paired t-test at p<0.05.

The average gingival index in the chlorhexidine group was significantlyhigher than in the propolis group (p=0.005), but there was no significant difference between the placebo and propolis mouthwash groups (p=0.080). Moreover, the average plaqueindex was significantly higher in the chlorhexidine group than the propolis group (p<0.001). However, no significant difference was observed between the placebo and propolis mouthwash groups (p=0.742). However, the average bleeding index in the chlorhexidine group was significantly lower than the propolis group (p=0.012), with no significant difference between the placebo and propolis mouthwash groups (p=0.134).

The present results showed that scaling and propolis mouthwash consumption significantly improved the bleeding on probing and the gingival indicescompared tothe placebo group. Therefore, this mouthwash can beuseful for treating chronic generalized gingivitis.

Hyper-immunoglobulin E syndrome (HIES),also known asJob's syndrome, is a rare primary immunodeficiency disorder characterized by a classic triad: elevated immunoglobulin E (IgE) levels, recurrent pneumonia with pneumatocele formation, and recurrent cold skin abscesses.

Case:

A 5-year-old girl was referred to the pediatric dentistrydepartment for tooth decay and multiple dental abscesses. Her medical history revealed elevated serum IgE levels, and she was receiving treatment with warfarin due to a history of jugular vein thrombosis. Clinical examination showed numerous skin abscesses alongside multiple eczemas.Angular cheilitis, de-papillation of the tongue, deep furrows on the tongue, numerous intraoral ulcerated lesions, poor oral hygiene, and gingivitis were seen in the intraoral examination.Due to the systemic conditions and thechild's non-cooperation, treatment under general anesthesia was planned.

Dentists play an essential role in the early diagnosis of HIES and in monitoring their oral health conditions. Timely extraction of over-retained primary teeth can reduce the necessity for complex treatments, thereby facilitating the management of patients with Job's syndrome.

Ameloblastoma is the second most frequenttype of odontogenic tumors. They are thought to be formed by epithelium of ectodermal origin, Histopathologically, ameloblastoma has plexiform, follicular, acanthomatous, desmoplastic, granular cell, and basal cell subtypes. Adenoid ameloblastoma, also called dentinal adenoid ameloblastoma,is a rare odontogenic tumor. About 40 cases have been reported, with the highest incidence in the fourteenth year of life (age range:25-52 years), indicating a small female population and a similar population for ameloblastoma. The differential diagnosis includes odontogenic lesions such as calcifying odontogenic cyst, calcified epithelial odontogenic tumor, ameloblastoma and adenomatoid odontogenic tumor (AOT). Histopathological results show that odontogenic epithelial tumors consist of nests, islands, cords, anastomotic chains and large areas of epithelium, ameloblast-like cells in the periphery, stellate reticulum-like cells in the space and cystic/microcystic patterns, acanthomatous changes and ductal patterns similar to AOT.

Case:

The aim of this report was to present a unique case of adenoid ameloblastoma affectingthe right side of mandible ina 47y.o womanwhich had a previous pathology diagnosis of adenoid cystic carcinoma for this lesion in her medical history.

Such rare casesof adenoid ameloblastomacan pose challenges in the initial diagnosisand treatment