Murat Unal

Temperature Rises During Application of Er:YAG Laser Under Different Primary Dentin Thicknesses

OBJECTIVE The present study investigated the effects of the Er:YAG lasers different pulse repetition rates on temperature rise under various primary dentin thicknesses. BACKGROUND DATA The Er:YAG laser can be used for restorative approaches in clinics and is used to treat dental caries. There are some reports that explain the temperature rise effect of the Er:YAG laser. Recently, the Er:YAG laser has been found to play an important role in temperature rises during the application on dentin. METHODS Caries-free primary mandibular molars were prepared to obtain dentin discs with 0.5, 1, 1.5, and 2 mm thicknesses (n=10). These discs were placed between the Teflon mold cylinders of a temperature test apparatus. We preferred three pulse repetition rates of 10, 15, and 20 Hz with an energy density of 12.7 J/cm2 and a 230 μs pulse duration. All dentin discs were irradiated for 30 sec by the Er:YAG laser. Temperature rises were recorded using an L-type thermocouple and universal data loggers/scanners (E-680, Elimko Co., Turkey). Data were analyzed by two-way ANOVA and Tukey tests. RESULTS Whereas the lowest temperature rise (0.44±0.09 °C) was measured from a 10 Hz pulse repetition rate at a dentin thickness of 2 mm, the highest temperature rise (3.86±0.43 °C) was measured from a 20 Hz pulse repetition rate at a 0.5 mm dentin thickness. CONCLUSIONS Temperature rise did not reach critical value for pulpal injury in any primary dentin thicknesses irradiated by a high repetition rate of the Er:YAG laser.

Evaluation of temperature rises during the application of different power levels of potassium titanyl phosphate and neodymium-doped:yttrium aluminum garnet lasers to external primary root canals

Background/purpose Nowadays, laser systems play crucial roles in endodontic treatments. Therefore, these systems should be investigated in terms of parameters that may prevent periodontal tissues damages during laser irradiation. In this context, the purpose of this study was to evaluate temperature rises during the application of different power levels of potassium titanyl phosphate (KTP) and neodymium-doped:yttrium aluminum garnet (Nd:YAG) lasers to external primary root canals. Materials and methods Sixty primary mandibular molars were selected and chemomechanical preparation was performed. KTP laser treatment was applied to 30 of these 60 samples and the remaining 30 received Nd:YAG laser treatment. The teeth samples received laser application (KTP or Nd:YAG) at three different power levels (1 W, 1.5 W, and 2 W, respectively, applied to 10 samples from each group). Nine holes were drilled (1 mm in diameter) through the level of the coronal, middle, and apical third of each tooth canal to provide entry for a Type L thermocouple wire, which was used to measure temperature changes. Data were assessed with two-way analysis of variance and the Tukey test. Results All power levels indicated statistically significant differences between Nd:YAG and KTP laser systems (P < 0.05). Moreover, the same regional (apical, middle, and coronal) comparisons performed between Nd:YAG and KTP laser systems showed statistically significant differences (P < 0.05). Conclusion All parameters of KTP laser indicated lower temperature rises than Nd:YAG laser. Therefore, KTP laser may be preferable to protect the periodontal tissues from harmful thermal effects during the endodontic treatment of primary root canals.

Clinical evaluation of apex locator and radiography in primary teeth

AIM The aim of this in vivo study was to evaluate the accuracy and reliability of electronic apex locater and radiographic determination of root canal length in primary teeth. METHODOLOGY A total of 32 human primary molar teeth (96 roots) were selected. After endodontic access preparation, root canals were irrigated with physiological saline solution. The access cavities were dried with cotton pellets and, the roots were dried with paper points before performing the electronic measurement. The root canal length measurements were first taken with an apex locater (EndoMaster), and then, a size ♯ 15 K-file was inserted into the root canal, and radiography was taken to determine the working length measurements. The measurement data were recorded and compared by one-way anova and Kruskal-Wallis tests. P < 0.05 was accepted for the significance. RESULTS The mean values for radiography were 13.23 ± 1.92 mm and for EndoMaster were 13.08 ± 1.77 mm. The accuracy of EndoMaster was 80.2% in correct measurements ±1 mm (P < 0.001). CONCLUSION The electronic apex locators could be useful in determining working length and thereby decreasing the need for radiographs and exposure to ionizing radiation in pediatric dental patients.

Peripheral ossifying fibroma associated with actinomycosis

Many types of localized reactive lesions may occur on the gingiva, including focal fibrous hyperplasia, pyogenic granuloma, peripheral giant cell granuloma and peripheral ossifying fibroma (POF). Clinically differentiating one from the other as a specific entity is often not possible. Histopathological examination is needed in order to positively identify the lesion. The POF is one such lesion, which is a reactive gingival overgrowth occurring frequently in the maxillary anterior region in teenagers and young adults. They are pink to red in color, and commonly associated with poor oral hygiene and early periodontal disease. We report in this study, the clinical report of a 12-year-old male patient with a POF in the maxilla associated with actinomycosis infection. Based on the clinical and histopathological evaluations, the diagnosis was concluded as POF. Clinical, radiographical and histological characteristics are discussed and recommendations regarding treatment and follow-up are provided.

The Comparison of Shear Bond Strenght of Different Bulk-Fill Composites to a Bioactive Dentine Substitute

Objective: The aim of this research was to compare shear bond strength(SBS) of various bulk-fill composites(BFC) to Biodentine(BD) with different time intervals. Materials and Methods: 300 cyclindrical acrylic blocks with a hole(4 mm diameter a 2 mm height) were prepared. The holes were filled with BD and after bonding application, 5 different BFC groups were divided into 10 main groups in 2 mm and 4 mm height, and these 10 main groups were divided into 3 subgroups according to three different waiting times(12 min, 24 hour and 2 week). After then, SBSs measured and the fractured surfaces were examined. Statistical analyzes were performed with Kolmogorov-Simirnov, Anova(F) and Tukey HSD tests. Results: Significant differences were found between the 2 mm and 4 mm Filtek Posterior BFCs. However, there was not significant differences the other BFC groups. In all BFC groups, there was significant difference found between the groups waited for 12 min and,24 h and 2 weeks. Conclusion: In clinically, we may prefer to use BFC at a height of 4 mm,onto BD with after 1 day of waiting time.

Piyojenik Granüloma: Olgu Raporu

Amac: Bu calismanin amaci, 13 yasinda bir kiz cocugunda gorulen piyojenik granulomanin tedavisinin ve 4 aylik takip surecinin degerlendirilmesidir. Olgu bildirimi: Piyojenik granuloma vaskuler tumorler icinde yer alan bir lezyondur. Gingivadaki butun reaktif lezyonlarin %30-60’ini teskil eder. Piyojenik granulomanin gelismesinde travma, damar duvari enfeksiyonlari, hormonal faktorler, yabanci cisimler, hipertansiyon ve zayif oral hijyenin etken oldugu bildirilmektedir. Tum yas gruplarinda ve her iki cinste de gorulebilir. Oral kavite de piyojenik granuloma lezyonlarina en sik gingivada rastlanir. Kesin tani sadece biyopsisi alinan dokunun histopatolojik incelenmesi ile konulabilir. Bu lezyonun tedavisi cerrahi eksizyondur. Yeterli bir cerrahi eksizyon yapilmazsa lezyonun tekrarlama riski vardir. 13 yasindaki kiz cocugu sol ust cene molar vestibuler bolgesindeki disetinde sislik ve bu bolgede kanama sikayetleri ile klinigimize basvurdu. Baslangic tedavisi olarak hastaya oral hijyen egitimi verildi, plak ve dis taslari uzaklastirildi. Lezyonun agizda gorulebilecek diger patolojik olusumlardan ayirici tanisini yapabilmek icin lokal anestezi altinda lezyon bisturi yardimiyla eksizyonel biyopsi ile alindi ve bolgedeki kanama Nd: YAG lazer ile 80 Hz ve 40 mj’de kontrol altina alindi. Sonuc: Eksizyonel biyopsi sonrasinda isik mikroskobu altinda histopatolojik olarak incelenen kitleye “Piyojenik Granuloma” tanisi konuldu. Kontrol muayenesinde klinik olarak herhangi bir nuks mevcut degildi.