Journal of Dental School
Volume:41 Issue: 1, Winter 2023

Dental stress is often considered as one of the important factors related to the patient's avoidance of dental visits. Considering the lack of comprehensive studies in this regard in Iran, we decided to design a study to explore the causes of dental stress.

The DASS (Depression-Anxiety-Stress Scale) was used for data collection. The first part of the questionnaire was related to demographic characteristics, including age, sex, education level and occupation and dental treatment experience. The second part included 21 questions related to the stress. The relationship between the score of questionnaire and psychological and demographic factors were analyzed.

Two hundred and fifty-eight patients completed the questionnaires (129 men,129 women). the highest age frequency was seen in the 21-30-year-old group (n=93). The mean age of the patients was 32 years old. women had higher stress scores (p=0.054), First timers had higher mean score to patients with a positive history of dental visit or endodontics treatment (p=0.03). level of education was no related to the stress score. Stress level had negative correlation with age (p=0.03).

Demographic and psychological factors are related to the stress. It's necessary to know the cause of stress in dentistry to have a better control on patient and better treatment procedure.

Due to the importance of using more effective varnishes to prevent dental caries, this study aimed to compare the effect of conventional casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and CPP-ACP with 1 and 2 w% nanosilver particles on microhardness of enamel of primary canines.

  The initial surface micro-hardness of 36 intact human deciduous canines were measured by a Vickers hardness tester, then samples were immersed in demineralization solution for 24 hours, and then the microhardness of samples was re-measured. All samples were randomly divided into 4 groups (n=9): (A) control group(without therapy), (B) conventional CPP-ACP, (C) CPP-ACP  with  1% nano silver, and (D) CPP-ACP  with  2% nanosilver. Then samples were entered into pH cycles for 7 days. At the end of pH cycling, the surface microhardness of samples was measured, and the mean for each group was calculated. Data analysis was performed using one-way ANOVA and Tukey analysis.

The mean enamel micro-hardness in all groups after demineralization decreased significantly (P<0.05), but this reduction was significantly less in all three experimental groups compared to the control group (P<0.05). There was no significant difference in the rate of surface microhardness changes between the three experimental groups (P>0.05).

Conventional CPP-ACP and CPP-ACP with 1 and 2 w% Nanosilver particles were equally effective on the enamel surface microhardness of human deciduous teeth. Silver Nanoparticles have no negative effect on enamel microhardness.

The aim of this retrospective study was to assess the dimensions of the mandibular molar socket for immediate implant placement, using cone-beam computed tomography (CBCT) imaging.

The CBCT images of 81 patients were selected based on the inclusion and exclusion criteria. In the OnDemand software, measurements were assessed by virtually positioning a regular Straumann implant (4.8 mm) in the regions of the first and second mandibular molars. The socket morphology, the buccolingual width of cancellous bone, the gap between the implant and the socket wall, the length of the root, the cross-sectional morphology of the mandible, and the height and thickness of the inter-radicular septum were all determined. The variables were compared using either the Student’s t-test or the Mann-Whitney U test.

Among the cross-sectional morphologies of the mandible, the undercut type (U) was found to be the most prevalent. The mean distance of the implant from the inferior alveolar nerve (IAN) was found to be 6.22 mm for the first molars and 5.17 mm for the second molars. Moreover, the mean horizontal distances from the implant to the mesial and distal socket walls were 2.01 and 2.30 mm for the first molars and 2.14 and 2.59 mm for the second molars, respectively. The width of the interradicular septum across various sections was found to have a significant correlation with the position of the tooth (P<0.05).

The majority of the samples exhibited the undercut (U type) morphology of the mandible. The interradicular septum in the second molar tooth was found to be insufficient. Overall, the assessment of pre-extraction CBCT scans and the virtual positioning of implants can be beneficial for surgical treatment planning. This approach can also aid in minimizing potential complications.

Objectives :

The present experimental study aimed to assess the in vitro effect of sodium bicarbonate (SB) on tooth discolouration.

Methods:

 Forty-five extracted anterior teeth were decoronated 2 mm apical to the cementoenamel junction. The crowns were immersed in tea solution for 7.5 days. The teeth were divided into three groups (n = 15 per group) on a random basis. The groups were exposed to either SB paste 94%, hydrogen peroxide (HP) 40%, or carbamide peroxide (CP) 45%. Then, teeth were bleached according to the manufacturers' instructions. Next, all tooth samples were immersed again in tea solution for 10 min. The CIE L*a*b* colour parameters of the teeth were evaluated at baseline (T1), after primary staining (T2), after bleaching (T3), and after re-staining (T4) using a spectrophotometer. The enamel surface morphology of one sample from each group was evaluated pre- and post-bleaching using scanning electron microscopy (SEM). Within-group and between-group comparisons were made using repeated measures ANOVA and Tukey’s test.

Results:

 94% of cases had color change(∆E) more than 3.5 with no enamel surface wear after Applying SB. HP showed a maximum bleaching effect of ∆E = 8.77. After re-staining, the SB group showed minimal staining (∆E = 3.77) compared to the HP and CP groups.

Conclusion:

 The present findings show that SB can chemically resolve tooth discolouration and prevent re-staining. Considering its low abrasiveness, optimal safety, low cost, antimicrobial activity, and availability, it seems to be ideal for use at home.

Objectives :

This study aimed to assess the relationship of skeletal class of malocclusion with some radiomorphometric indices of the mandible in short-face patients.

Methods :

This cross-sectional study was conducted on 179 short-face patients between 17 to 30 years who sought orthodontic treatment during 2013 to 2020. The gonial and antegonial angles, and type and depth of antegonial notch were assessed bilaterally on traced panoramic radiographs. The correlation between radiomorphometric indices and class of malocclusion was analyzed using One-way ANOVA and Independent T-test by SPSS version 25 (alpha=0.05).

Results:

 The mean size of gonial angle was significantly different among the three classes of malocclusion (P<0.001), and the largest gonial angle was recorded in class III, and the smallest in class I patients. The mean size of antegonial angle and antegonial depth were not significantly different among the three classes of malocclusion (P=0.487). The difference in the mean size of gonial and antegonial angles was not significant between males and females (P=0.119, and P=0.176, respectively). However, the mean antegonial depth in males was significantly greater than that in females (P<0.001). Type I antegonial notch was more common in females than males at both sides. Age had no significant correlation with gonial angle, antegonial angle, or antegonial notch depth (P=0.422, P=0.737, P=0.392, respectively).

Conclusion:

 Facial growth pattern in short-face patients can be predicted with antegonial angle. Also there is significant correlation between skeletal class of malocclusion and the size of gonial angle.

Objectives :

Children frequently encounter dental problems related to traumatic dental injuries (TDIs). This study aimed to investigate TDIs among children aged 7-13 years, who were admitted to the Tehran School of Dentistry in Tehran, Iran.

Methods :

This retrospective study was performed on 70 patients with 129 TDIs. Information, such as age at the time of the accident, gender, cause and type of TDI, the interval between the accident and the emergency care, and treatment, was gathered from the patients’ records. During the follow-up session, the pulp sensibility, probing, and percussion tests were conducted. The collected data was statistically analyzed using Fisher’s exact test and Chi-square test. The significance level was set at P<0.05.

Results:

 A total of 129 TDIs were reported during 2018-2021. Maxillary central incisors (80.62%) were the most commonly involved teeth, followed by maxillary lateral incisors (17.82%) and mandibular lateral incisors (1.55%). Falls were the main contributor to TDIs (31.78%). The most frequent TDIs involved enamel-dentin fractures without pulp involvement (37.20%) and subluxation (19.37%), followed by enamel-dentin fractures exposing the pulp (10.85%), avulsion (10.85%), infraction (4.65%), lateral luxation (3.87%), intrusion (3.87%), and extrusion (3.10%). Splinting (26.61%) and restoration (23.74%) were the most frequent treatments. The average follow-up period was 2-3 years, with a survival rate of 67%.

Conclusion:

 It appears that a significant number of parents are unaware of the necessity of immediate treatment and regular follow-up after TDIs, which can result in a high rate of treatment failure.

Objectives :

A distomolar tooth, also known as a distodens, is a supernumerary tooth located distally to the third molars. It is an uncommon phenomenon with a reported prevalence of 0.02% to 0.16% across various countries. Distomolars can manifest as singular or multiple, erupted or impacted, and can occur unilaterally or bilaterally. To the best of our knowledge, very few cases of three distomolars in one patient have been reported in the English literature.

Case :

This study presents the case of a healthy 22-year-old male who was found to have three impacted distomolars. These distomolars were located bilaterally in the maxilla and unilaterally on the left side of the mandible. They were discovered incidentally during a routine radiographic examination. As the patient expressed no discomfort or complaints related to this condition, no treatment was administered. Instead, the patient was placed on a regular follow-up.

Conclusion:

 Although the occurrence of distomolars is rare, clinicians should regard it as a potential risk factor for the development of intraosseous lesions, which are often associated with an impacted tooth.