Journal of Istanbul University Faculty of Dentistry最新文献

Purpose: The purpose of this study was to investigate the impacted supernumerary teeth which were initially detected on panoramic radiographs by using cone beam computed tomography (CBCT).

Materials and methods: In this retrospective study, supernumerary teeth diagnosed on panoramic radiographs taken from patients who had admitted for routine dental treatment were evaluated using CBCT. Patients' age, gender, systemic conditions as well as number of supernumerary teeth, unilateral-bilateral presence, anatomical localization (maxilla, mandible, anterior-premolar-molar, mesiodens-lateral-canine, parapremolar-paramolar-distomolar) shape (rudimentary, supplemental, tuberculate, odontoma), position (palatal-lingual-buccal-labial-central), shortest distance between the tooth and adjacent cortical plate, complications and treatment were assessed.

Results: A total of 47 impacted supernumerary teeth in 34 patients were investigated in this study. Of these, 33 (70.2%) were unilateral and 14 (29.8%) were bilateral. Only 1 supernumerary tooth was found in 27 patients (79.4%) whereas 7 patients (20.6%) had 2 or more supernumerary teeth. Most of the teeth located in the anterior region (74.4%) of the jaws and maxilla (74.4%). Twenty teeth (42.5%) were mesiodens, 11 (23.4%) were lateral or canine, 14 (29.7%) were parapremolar and 2(4.4%) were distomolar. Twenty-seven teeth (57.4%) were rudimentary, 15 (31.9%) were supplemental and 5 (10.7%) were odontoma in shape. The shortest distance between the supernumerary tooth and adjacent cortical plate varied between 0 to 2.5 mm with a mean of 0.66 mm. The most common clinical complaint was the non-eruption of permanent teeth (42.5%). All supernumerary teeth were removed under local anesthesia. Orthodontic traction was performed for those impacted permanent teeth if necessary.

Conclusion: Impacted supernumerary teeth are usually in close proximity to cortical bone. Although this may facilitate surgical access, there is a risk of damaging surrounding anatomical structures. Therefore, CBCT evaluation of impacted supernumerary teeth for accurate planning is recommended.

Purpose: This study evaluated the effects of different adhesive systems on repair bond strength of aged resin composites.

Materials and methods: Ninety composite discs were built and half of them were subjected to thermal aging. Aged and non-aged specimens were repaired with resin composite using three different adhesive systems; a two-step self-etch adhesive, a two-step total-etch adhesive and a one-step self-etch adhesive; then they were subjected to shear forces. Data were analyzed statistically.

Results: Adhesive type and aging significantly affected the repair bond strengths (p<0.0001). No statistical difference was found in aged composite groups repaired with two-step self- etch or two-step total-etch adhesive. One-step self-etch adhesive showed lower bond strength values in aged composite repair (p<0.0001).

Conclusion: In the repair of aged resin composite, two-step self-etch and two-step total-etch adhesives exhibited higher shear bond strength values than that of one-step self-etch adhesive.

Purpose: The purpose of this study was to evaluate the efficacy of tranexamic acid (TXA) in reducing blood loss during surgically assisted rapid palatal expansion (SARPE) procedure.

Subjects and methods: A total of 34 patients (12 male, 22 female) who had been treated surgically under general anesthesia with SARPE including pterygoid disjunction for transverse maxillary deficiency (TMD) were included in this study. The study group (n=17) received intravenous (IV) TXA 10 mg/kg as a preoperative bolus; the control group (n=17) received normal saline solution. Preoperative and postoperative haemoglobin and haematocrit values, intraoperative blood loss, and any blood product transfusion were recorded.

Results: Blood loss during SARPE was statistically significantly less in the study group than the control group (p=0.0001).

Conclusion: Preoperative IV administration of TXA can effectively control blood loss during when SARPE with pterygoid disjunction is performed.

It is very important that the dentists have sufficient information about possible variations in the expected root canal configurations in order to achieve success in endodontic treatment. In addition to having adequate knowledge on the variations of the root canal anatomy, periapical radiographs from different angles, careful examination of the pulp chamber floor, and use of dental operation microscope during the procedure are also important factors that contribute to the diagnosis of the additional roots and canals. The aims of this article are to present the diagnostic approach and root canal treatments of two maxillary first premolar teeth with three canals in two patients.

Despite numerous technological and medical developments achieved in recent years, a significant amount of occupational health problems still exist in modern dentistry. The risk of eye injury is mostly attributed to the use of high-speed hand pieces and ultrasonic devices. A dental clinic may be the source of eye-related infection and injury because of mechanical, chemical, microbiological and electromagnetic irritants. Accidents may cause facial injuries that involve eyes of the clinicians, patients as well as dental assistants. Eye injuries can vary from mild irritation to blindness. The use of eye protection tools, such as protective goggles and visors, reduces the risk of eye damage or complete loss of vision while working with dangerous and floating materials. Therefore, all precautions should be taken, even when performing common procedures for which the risk expectancy is relatively low. Clinicians should be aware that they are also responsible for providing adequate protection for their assistants and patients, as well as themselves.

Purpose: The aim of this study was to compare the cleanliness of root canal walls after retreatment using ProTaper Next (PTN), ProTaper Universal Retreatment (PTR) nickel-titanium (NiTi) systems and Hedström hand files in curved mesial canals of mandibular molar teeth and the time required for gutta-percha and sealer removal.

Materials and methods: Ninety mandibular molar teeth with curved mesial roots were instrumented up to #35.04 with Mtwo NiTi rotary instruments and obturated using the continuous wave of condensation technique. Removal of gutta-percha and sealer was performed using one of the following: PTN and PTR NiTi systems and Hedström hand files. Samples were placed on the VistaScan phosphor plates in the mesio-distal direction and the radiographs were taken. The digital radiographs were analyzed using AutoCAD software. Also, the total time required for gutta-percha removal was calculated by a chronometer.

Results: The total retreatment time was significantly shorter in the PTN and PTR groups compared with the manual group (p<0.05). There was a significant difference between the groups according to the total residual gutta-percha and sealer (p<0.05). The PTN and PTR groups left significantly less gutta-percha and sealer remnant than the manual group (p<0.001).

Conclusion: Within the limitations of this study, the PTN and PTR groups showed less residual gutta-percha and sealer than the manual group. The NiTi rotary systems were significantly faster than the manual group in the time required for gutta-percha and sealer removal.

Purpose: To evaluate the efficacy of different obturation techniques in root canals instrumented either by hand or rotary instruments with regard to the percentage of gutta- percha-filled area (PGFA).

Materials and methods: One hundred and sixty extracted mandibular premolars with single, straight root canals were studied. Root canals were prepared to an apical size of 30 by hand with a modified crown-down technique or the ProTaper and HEROShaper systems. Teeth were divided into eight groups (n=20) according to the following instrumentation and obturation techniques: G1: Hand files+lateral condensation (LC), G2: Hand files+Thermafil, G3: ProTaper+LC, G4: ProTaper+single-cone, G5: ProTaper+ProTaper-Obturator, G6: HEROShaper+LC, G7: HEROShaper+single-cone, G8: HEROShaper+HEROfill. Horizontal sections were cut at 1, 3, 5, 7, 9, 11 and 13 mm from the apical foramen. A total of 1120 sections obtained were digitally photographed under a stereomicroscope set at 48X magnification. The cross-sectional area of the canal and the gutta-percha was measured by digital image analysis and the PGFA was calculated for each section.

Results: The mean of the PGFA in Thermafil (G2), ProTaper-Obturator (G5) and HEROfill (G8) groups was significantly higher than the other groups. In G3 and G4, PGFA showed no significant difference in the apical segments whereas PGFA was significantly higher at the middle and coronal segments in G3. In G6 and G7, PGFA showed no significant difference in the apical and middle segments whereas PGFA was significantly higher at the coronal segments in G6.

Conclusion: The carrier-based gutta-percha obturation systems revealed significantly higher PGFA in comparison to single-cone and lateral condensation techniques.