Journal of Dental Medicine

Anterior tooth crown fracture in children is something that each dentist will confront many times during his professional career.We studied the prevalence of anterior teeth crown fractures between 7-14 years old students in Tehran and some relevant factors like sex, age, the traumatized tooth, amount of overbite and overjet, upper lip coverage, jaw that had fractured tooth or teeth and place of fracture in fractured crown.1338 boys and 1184 girls were in this study. Tooth fracture was almost the same in boys and 1184 girls with the prevalence of 8%. Fracture was mostly in enamel and average year of fracture was 10 years.Increased overjet and overbite had direct relation and indirect relation with fracture, also enough lip coverage showed less fracture.

Statement Problem: A few studies have been conducted about bioglass posts.
Aim: The aim of this study was to compare bioglass posts with prefabricated metallic posts in clinical performance of extensive composite restorations for anterior endodontically treated teeth.

Materials and Methods: Sixty endodontocally maxillary anterior teeth, with horizontally or vertically destruction, were selected. Teeth were divided into two groups based on the kind of post: Metallic prefabricated parapost and bioglass post. Each group was divided into three subgroups based on anterior bite: normal, deep bite and edge to edge. Gutta-percha was removed from 2/3 of canal length for parapost and 1/3 for bioglass post. After etching with phosphoric-acid (37%) and applying dentine bonding syntac, Duo cement was used for the adhesion of bioglass post and a self cured composite (Degufil) for parapost. Restoration was done with a hybrid composite (Heliomolar). Follow up studies, radio-graphically and clinically, were done every three months for a 1.5-year period. Exact Fisher and Pearson tests were used for data analysis.
Results: Apical lesion was not observed in any of the radiographs. Post seal was increased by resin cement and dentin bonding agent. Post type did not significantly affect on the clinical success rate of the restorations. The retention of restoration, for both posts, was the same. Crown destruction had no significant effect on success rate. The type of anterior bite had a significant effect on success rate, as the total 6.6% failure rate was related to the patients with anterior deep bite.
Conclusion: It is suggested to use metallic paraposts and bioglass posts, in extensive composite restorations for patients with deep-bite, more conservatively.

Statement of Problem: Choosing an appropriate tooth for edentulous patients is a very important step in dentistry.
Purpose: This research has been done for determination of proper procedure for tooth selection in edentulous patients.
Methods and Materials: In this cross- sectional study 100 student and people who have come to a medical
center (range 20-30 years old) were collected randomly and the size of their anterior teeth were determined. A gauge with 0.01 mm accuracy and flexible plastic millimeter was used in order for measurement of anatomic landmark. For achieving the relation between the sizes of teeth statistical analysis was done.

Results: 50% of patients were female and the other 50% were male. We found a relationship between mesiodistal width of six maxillary anterior teeth and mesiodistal width of six mandibuMary teeth that can be shown as follow In men: six mandibular anterior teeth width= 0.S3 * width of six maxillary anterior teeth -2.008 In women: six mandibular anterior teeth width- 0.56 * width of six maxillary anterior teeth + 9.53 Also strong meaningful relationships between width of six anterior maxillary teeth and the width between corners of the lip in curve position have been noticed only in men which can be show' as follow:width of Six mandibular anterior tceth= 39.63 + 0.21+ the width between corners of lip in curve position for men
Conclusion: Although there are different ways for prediction of teeth size, it seems these findings can be
helpful in determining and prediction of it.

Background and Aim: The structural rehabilitation of a pulpless tooth is critically important to ensure a successful restorative outcome following endodontic treatment. A post and core is often indicated for the retention and reinforcement of the final restoration. But, the clinical situation is significantly challenging if the root exhibits immature development or there is a thin root wall that can compromise the prognosis for a long- term successful treatment. The purpose of this in vitro study was to evaluate different methods of intraradicular reinforcement in structurally compromised roots.

Materials and Methods: In this experimental study, seventy two extracted intact maxillary central incisors with similar size, shape and root anatomy were selected. After root canal therapy in 60 teeth, an acrylic laboratory bur was used to thin the cervical area and simulate the thin dentinal walls of immature teeth. The preparation was performed through the palatal access and extended 5mm apical to CEJ. The remaining 12 teeth remained unprepared to serve as positive control group. Cases were randomly divided into six groups of 12 teeth each and restored as follows. In the 12 cervically unprepared teeth (positive controls) the composite resin with dentin bonding agent (DBA) was placed in access cavity and cured for 120 seconds. This technique was also applied to other groups when the access was restored with composite. In the second group, the access cavity was restored with composite only to the level of CEJ. In the third group the cervically prepared teeth were reinforced with cement resin (Enforce) and a prefabricated post was placed in 5mm apical to the CEJ. In the fourth group, the cervically prepared teeth were reinforced with composite resin and DBA by a clear plastic post. In the fifth group the cervically prepared teeth were reinforced with composite resin and dba and a cast post. In the sixth group the cervically prepared teeth were restored with composite resin and dba with a prefabricated post. All of the specimens were mounted by rubberized technique and tested in the Instron universal testing machine. The fracture loads in samples were analyzed with ANOVA and Duncan tests with p<0.05 as the limit of significance.

Results: Significant differences in fracture resistance were observed between the first and second groups compared with others. The highest fracture resistance values were recorded for first group while the lowest were registered for the second group. Fracture resistance of the third, fourth and fifth groups had no significant statistical differences with others and fracture resistance of sixth group was the highest with significant difference (P<0.05).

Conclusion: From this study, it may be concluded that the use of a dba and a composite resin in thin-walled roots reinforces the immature teeth and facilitates the use of post.

Background and Aims: Electric pulp testing is used for diagnosis of the pulp status. This test is technique sensitive and hence may elicit positive or negative false response in case of inaccurate use. The optimal site for placement of the probe tip has not been determined. The aim of this study was to evaluate the effect of pulp tester probe placement site on the response of maxillary teeth.
Materials and Methods: A total of 378 teeth (126 central incisors, 126 lateral incisors and 126 canines) in 67 voluntary 20-35 year-old patients were selected. Three sites on each tooth (incisal edge, labial and lingual surfaces) were tested with an electrical pulp tester and responses were recorded. Data were analyzed by Repeated Measure ANOVA test.
Results: The central teeth showed significantly lower sensation threshold than lateral and canine teeth (P<0.001). The incisal edge of tooth were significantly more sensitive compared to labial and lingual surfaces (P=0.008).
Conclusion: This study showed that the optimum site for placement of pulp tester probe was incisal edge.