Journal of Dental School

Objectives Treatment of chipped or fractured porcelain with composite resin is considered as an economic treatment for minor fractures in ceramics. The aim of this study was to evaluate the effect of different ceramic surface treatments on bond strength of methacrylate-based and silorane-based composite resin to IPS Empress 2.
Methods Sixty IPS Empress 2 ceramic discs were fabricated and after etching with 9.6% hydrofluoric acid, they were divided into six groups:
(1) P90 primer and bonding agent + Filtek P90 composite resin; (2) Single Bond + Filtek Z250 composite resin; (3) similar to the first group
+ silane pretreatment; (4) similar to the second group + silane pretreatment; (5) silane pretreatment + Filtek P90 composite resin; (6) silane pretreatment + Filtek Z250 composite resin. Each specimen was subjected to shear load until fracture occurred. Statistical analysis was performed using one-way ANOVA, Tukey’s test and t-test.
Results Regardless of the type of surface treatment, Z250 composite demonstrated significantly higher shear bond strength than P90 composite (P < 0.05). Group 4 showed the highest shear bond strength values with statistically significant difference with other groups while the fifth group showed the least values (P < 0.05).
Conclusion Silane coating along with the application of adhesive system and etching in methacrylate-based composite was the most efficient surface treatment in terms of bond strength.

Objectives This study aimed to investigate dentinal crack rate following parapulpal pin insertion in anterior primary teeth.

Methods Thirteen sound freshly extracted primary canine teeth were horizontally sectioned 1 mm above the cementoenamel junction (CEJ). All samples were thoroughly inspected to ensure that the teeth had no cracks. The teeth were then mounted in acrylic blocks, and subjected to drilling and insertion of a single parapulpal pin in the prepared hole. The teeth were then sectioned perpendicular to the already prepared surface at 1, 2 and 3 mm depths for further evaluation under a stereomicroscope (x12 and x25 magnifications).

Results No crack or crazing was observed in teeth in the control group while one out of 11 teeth in the case group had a crack.

Conclusion The use of 0.53 mm diameter self-threading pin did not increase the risk of crack formation in dentin of anterior primary teeth prior to composite restoration.

Objectives This study was undertaken to observe the frequency of different diagnostic groups for temporomandibular disorders (TMDs) in patients who sought treatment for TMD in an outpatient clinic of a dental school.

Methods Files of patients who received a diagnosis of TMD in a period of 24 months were evaluated. Clinical and demographic data extracted from 213 patient files meeting the inclusion criteria were analyzed.

Results According to the classification of RDC/TMD, 100 patients were diagnosed with myofascial pain and 113 patients were diagnosed with disc displacement. Myofascial pain was the most common diagnosis among women; disc displacement with reduction (DDwR) was the most common diagnosis in men. Self-reported bruxism was reported by 59% of the patients. The amount of maximal mouth opening showed a statistically significant difference among patients with different clinical diagnoses and also between males and females (P < 0.05). The mean visual analog scale (VAS) score was 4.9 ± 2.4 in all diagnostic subgroups, and pain severity was higher in female patients but not significantly (P > 0.05).

Conclusion Demographic characteristics of patients with TMD presenting to a dental school clinic in Ankara, Turkey were similar to those reported in the literature. A thorough anamnesis can provide more detailed information about parafunctional activity and sociodemographic factors and enhance accurate diagnosis.

Objectives Dental anxiety can be potentially problematic. Anxiety must be controlled in highly anxious patients in order to ensure a smooth procedure and prevent potential complications. Awareness and reassurance are believed to be efficient for anxiety control in patients undergoing dental procedures especially dental implant treatment. This study sought to assess the effect of awareness and reassurance of patients undergoing dental implant treatment on their level of anxiety.

Methods In this experimental study, 40 dental implant candidates with a mean age of 37.5 years were selected and randomly assigned into two groups (n = 20). Case group patients received awareness and reassurance through a standard interview while controls only received routine information. Level of anxiety of the patients was determined pre- and postoperatively using the Spielberger State-Trait Anxiety Inventory (STAI). The anxiety scores of the patients in the two groups were statistically analyzed by Mann-Whitney U test.

Results The preoperative anxiety scores of cases and controls were not significantly different (54.73 vs. 57.55; P > 0.05). However, the anxiety score of the case group was significantly lower than that of the control group postoperatively (52.30 vs. 60.64; P = 0.004). Also, male patients had a significantly lower anxiety score than females (P < 0.05).

Conclusion Awareness and reassurance through a standard interview can efficiently decrease the level of anxiety of dental implant candidates. Furthermore, female patients often experience higher level of anxiety than males.

Objectives This study aimed to compare the efficacy of panoramic radiography and the buccal object rule in intraoral periapical radiography for localization of impacted maxillary canine teeth.

Methods A total of 20 panoramic radiographs depicting 28 displaced maxillary canines were evaluated. The ratio of the mesiodistal width of the impacted canine to the mesiodistal width of the ipsilateral central incisor was calculated and referred to as the canine-incisor index (CII). The height of the crown of each displaced canine was classified in vertical plane relative to the adjacent incisor as apical, middle or coronal. Position of impacted maxillary canines was also determined on two periapical radiographs using the buccal object rule. Surgical exposure and direct observation of impacted teeth were later performed and served as the gold standard. The data were analyzed using SPSS and t-test.

Results There was an overlap in the CII range of the buccally (0.78–1.48) and palatally (1.15–1.75) positioned impacted canines. When considering the height factor in the middle and coronal zones, a significant difference was noted between the CII of buccally (0.78–1.1) and palatally (1.15–1.75) positioned teeth enabling determination of their buccolingual orientation (P < 0.05).

Conclusion For the impacted maxillary canines located in the middle and coronal zones (90% of cases), the CII of 1.15 and higher represents palatal impaction while the CII smaller than 1.15 represents buccal impaction.

Objectives The present study evaluated the effect of bar and ball attachment designs on retention and stability of a mandibular overdenture supported by four implants.

Methods An edentulous mandibular acrylic resin model with four implants in the anterior part of the ridge (A, B, D and E) was fabricated. A metal framework simulating the overdenture was also fabricated. Totally, 30 overdentures were divided into three groups based on the attachment design; BL: Four ball attachments in A, B, D and E positions; BB: One bar attachment between B and D positions and two ball attachments at positions A and E; BR: Bar attachments between the positions A, B, D and E with two posterior extensions. To evaluate the retention and stability of the overdenture, tensile dislodging forces were applied in three directions of vertical, oblique and anterior- posterior by a universal testing machine. One-way ANOVA and Tukey’s HSD test were performed to analyze the data. All tests were carried out at 0.05 level of significance.

Results There were statistically significant differences between the groups in the peak load (P < 0.001). The peak load values for vertical, oblique and anterior-posterior dislodging forces were the highest for BL with 49.38 ± 2.19 N, 52.19 ± 1.44 N, and 49.03 ± 5.89 N, respectively, while these values were the lowest for BR with 29.78 ± 2.52 N, 12.10 ± 0.45 N, and 6.26 ± 0.45 N, respectively.

Conclusion The attachment designs affected the retention and stability of mandibular implant-supported overdentures.

Objectives E-cadherin is a transmembrane glycoprotein, which is responsible for cell adhesion and its expression decreases in dysplastic lesions. This study aimed to assess the expression of this marker in oral lichen planus (OLP) with and without dysplasia to assess its potential for use as a predictor of malignant transformation.

Methods This descriptive, cross-sectional study was conducted on 44 OLP specimens using immunohistochemistry (IHC) by streptavidin- biotin technique. For this purpose, E-cadherin antibody was used and the intensity score (IS), proportional score (PS) and total score (TS) were calculated. Data were analyzed using SPSS version 21. The relationship between the intensity of expression of E-cadherin and dysplastic changes was assessed using the Mann Whitney U test. P < 0.05 was considered significant.

Results The TS of E-cadherin expression was 3 to 6 and 3 in the superficial and deep layers of 100% of specimens with dysplasia, respectively. The TS of E-cadherin expression was 3 to 6 in the superficial layer of 82.5% of specimens and 3 in deep layers of 81.2% of specimens without dysplasia. According to the Mann Whitney U test, the expression of E-cadherin in the superficial (P = 0.90) and deep (P = 0.35) layers was not significantly different between the two groups of OLP with and without dysplasia.

Conclusion No significant difference was found in the expression of E-cadherin in OLP specimens with and without dysplasia. It may be concluded that in contrast to other preneoplastic lesions, dysplastic changes of OLP do not follow other malignant transformation patterns in the oral mucosa.

Impaction of maxillary central incisors is not common. Treatment of an impacted central incisor is challenging as it relates to facial esthetics and dental function.

Although impaction of permanent teeth is rarely diagnosed in mixed dentition period, an impacted central incisor is usually diagnosed when there is a delay in the eruption of tooth.

Tooth impaction may result from a number of local etiological factors such as lack of space for eruption, presence of supernumerary teeth, disturbances in the path of eruption and presence of pathological cysts. Management options for such teeth include (1) surgical extraction and moving the lateral incisor to replace the central incisor and changing the anatomy of other teeth, (2) extraction of the impacted tooth followed by bridge or implant placement, (3) surgical repositioning of the impacted tooth, and (4) orthodontic correction of the impacted tooth.

The purpose of this article was to describe surgical exposure and orthodontic treatment of a horizontally impacted permanent maxillary central incisor, parallel to the occlusal plane in a 9-year-old girl. The impacted tooth was surgically exposed and traction was done with orthodontic intervention.