Tolga Topcuoglu

Effect of Er:YAG Laser Pulse Duration on Shear Bond Strength of Metal Brackets Bonded to a Porcelain Surface

OBJECTIVE The aim of this study was to compare the effect of different Er:YAG laser pulse durations on the shear bond strength (SBS) of metal brackets bonded to porcelain with two different adhesive systems. BACKGROUND DATA Orthodontic brackets do not bond well to feldspathic porcelain surfaces, using resin cement. Various treatment methods have been suggested for the porcelain surface to improve bond strength. Thus far, no orthodontic study has evaluated the effect of different Er-YAG laser pulse durations on porcelain surfaces with or without sandblasting. METHODS In the present study, 150 porcelain crowns were assigned to 10 groups differing in adhesive system and surface treatment. In five groups, the adhesive system was RelyX(™) U 200 and in the other five, Transbond XT was used. For each adhesive system, the porcelain surfaces were treated in one of five different ways: sandblasted, Er:YAG laser short pulse (SP), Er:YAG laser super short pulse (SSP), sandblasted+SP, or sandblasted+SSP. The sandblasted group with Transbond XT served as the control. SBS test was conducted for each group. Samples were examined by scanning electron microscopy. ANOVA and independent t test were used for statistical analysis. RESULTS The control group had increased roughness and the highest SBS. Er:YAG laser application to the sandblasted porcelain flattened the roughness, and the effects of SP and SSP were similar. CONCLUSIONS Er:YAG laser application did not allow for elimination of the hydrofluoric acid step. RelyX U 200 is a viable alternative to Transbond XT on sandblasted porcelain.

Evaluation of the Effects of Different Surface Configurations on Stability of Miniscrews

Introduction. The aim of this study was to analyze the effects of screw design and force application on the stability of miniscrews, using RTT, SEM, and histomorphometric analyses. Materials and Methods. Eighty cylindrical, self-drilling, and Ti6Al4V alloy miniscrews (1,6 × 6 mm) were used. Four mini-screws were inserted in fibulas of each rabbit, and 115 G of force was immediately applied. Four miniscrews were inserted in the other fibula, on which no force was applied. Eight weeks after insertion, osseointegration between miniscrew and the surrounding bone was evaluated by the histomorphometric analyses, SEM, and RTT. Kruskal-Wallis and the paired t-tests were used for statistical analysis. Results. Values obtained from Group I were significantly higher than those of the other loaded groups (P < .05). There were no differences in RTT scores among Groups II, III, and IV. Similar findings were also observed for unloaded mini-screws. There was no significant difference between Groups I and IC, while the differences between loaded and unloaded controls for each miniscrew were statistically significant. Conclusions. Immediate loading of miniscrews does not impair screw stability. Also, the diameter of miniscrew and more frequent thread pitches have a positive effect on stability; however, length of miniscrews does not have a significant effect on the stability.

Can laser welding stop corrosion of new generation magnetic attachment systems

Abstract Rare earth magnets have been used in both prosthodontics and orthodontics, but their corrosion tendency in the oral cavity limits long term clinical application. The purpose of this study was to evaluate corrosion of new generation magnetic attachments in two different pH corrosive environments and to answer the question: ‘can corrosion reach the magnet in spite of laser welding?’. Forty magnetic attachment systems (Hyper slim, Hicorex slim, Dyna and Steco) were immersed in two media, 1% lactic acid solution (pH = 2·3) and 0·9% sodium chloride solution (pH = 7·3) for 14 days. After immersion, samarium, cobalt, neodymium and boron ions released from the magnetic attachments were analysed using inductively coupled plasma mass spectrometry. Moreover, iron ions released from the magnetic attachments were detected by atomic absorption spectroscopy. The data were statistically evaluated with Kruskal–Wallis and post hoc Tukey–Kramer multiple comparisons test (α = 0·05). In all groups, Dyna, Hicorex slim, Hyper slim and Steco, there were statistically significant differences between sodium chloride and lactic acid solutions. Different amounts of neodymium, boron, iron, samarium and cobalt ions released from magnetic attachments were detected in the corrosive environments. There was a significant decrease in the corrosion of the magnets, but corrosion was not completely stopped. Laser welding zone was broken down, and corrosion reached the magnet.

Multiple tooth anomalies in a nonsyndromic patient with class II division 2 malocclusions: A case report and a literature review

Reports in the literature about the craniofacial characteristics of patients with class II division 2 malocclusions show a lot of different patterns accompanied by palatally displaced upper incisors, congenital missing teeth, polydiastema, fusion, germination, tooth impaction, peg-shaped lateral incisors, persistent teeth, hypodontia, persistent deciduous teeth, transpositions, and supernumerary teeth. The following case report focuses on the description of the clinical characteristics observed on a patient with a very unusual conjunction of dental and skeletal anomalies mentioned above, as well as a literature review on the related issues. Extra-intra-oral examinations, radiographic evaluations, orthodontic consultation, and reviewing the literature concluded that this nonsyndromic patient that refused to receive all dental treatment approaches is special with its uniqueness.

Effects of water flow rate on shear bond strength of orthodontic bracket bonded to enamel surface after Er:YAG laser ablation.

OBJECTIVE The aim of present study was to evaluate the effect of water flow rate on enamel surface roughness and shear bond strength (SBS) of orthodontic brackets after Er:YAG laser ablation. BACKGROUND DATA It is well known that external water supply is a fundamental requirement for Er:YAG laser efficiency on dental hard tissues. However, there is no consensus considering the water flow rate used during Er:YAG laser ablation. METHODS Eighty sound human upper premolar teeth were used in the present study. Seventy-six teeth were assigned into four groups according to surface treatments. The 37% phosphoric acid-etched group served as the control. Er:YAG laser irradiation was performed in three subgroups with water flow rates of 25, 36, and 48 mL/min, respectively. All specimens were subjected to a SBS test. One specimen from each different surface treatment modality was examined by scanning electron microscopy. Kruskal-Wallis test was used to compare the SBS value of each group. RESULTS Although the control group had the highest SBS value, statistically no significant differences were found among groups. CONCLUSIONS Er:YAG laser application with a water flow rate of 48 mL/min produced better enamel surface alterations without any thermal damage to yield higher SBS values.

Effect of Different Temporary Crown Materials and Surface Roughening Methods on the Shear Bond Strengths of Orthodontic Brackets

OBJECTIVE The aim of this study was to evaluate the effect of different temporary crown materials (TCMs) and surface roughening methods on the shear bond strength (SBS) of orthodontic brackets. BACKGROUND DATA TCMs are widely used during orthodontic treatment in teeth in need of prosthetic treatment, to prevent damage to the final restoration. However, there is no consensus considering the best method for roughening of the surface of TCMs. METHODS Five different TCMs [Dentalon Plus-(D), Basworth Trim II-(B), Voco Structure Premium-(V), 3M ESPE Protempt 4-(P), and Revotek LC-(R)] were used in this study. Different surface roughening methods (37% phosphoric acid, sandblasting, and Er:YAG laser) were employed in three subgroups (n=20). The SBS test was used to assess the durability of all groups. Scanning electron microscopy (SEM) analysis was performed on a representative specimen in each group. RESULTS The highest mean SBS value was observed in group V, followed by groups D and P, regardless of the surface treatment. The lowest SBS values were observed in group B. The laser-irradiated groups had higher SBS values than the sandblasted and acid-etched groups. Furthermore, a significant difference in SBS values was observed between the laser-irradiated group V and all other groups (p<0.005). CONCLUSIONS The effects of the chemical nature of TCMs on the SBS values appeared to be clinically negligible, whereas the type of surface treatments had a significant influence on bond strengths. Er:YAG laser irradiation caused a significant increase in bond strength between the TCMs and orthodontic brackets.

Yeni doğan dudak damak yarıklı bebeklerin alçı modellerinin değerlendirilmesi

Amac: Dudak ve damak yariklari bas-boyun bolgesinin sik gorulen konjenital malformasyonlari arasindadir. Bu calismada Gaziantep Universitesi Dis Hekimligi Fakultesi Ortodonti Anabilim Dali’nda tedavi edilen dudak damak yarikli hastalarinin cinsiyet, yas, yarik tipi, anterior yarik genisligi, midpalatal ve posterior palatal genisliklerine gore degerlendirilmesi amaclanmistir. Gerec ve Yontemler: Calismada klinigimize gelen 39 dudak damak yarikli hastanin kayitlari kullanildi ve yas, cinsiyet, yarik tipleri degerlendirildi. Analiz icin alci modeller uzerinde olcumler yapildi. Kullanilan referans noktalari; c, c’ noktalari (kaninler bolgesi), t, t’ noktalari (tuber noktalari), g, g’ noktalari (c ve t noktalari arasi mesafenin orta noktasi) olarak belirlendi. Bulgular: Calismaya dâhil edilen bireylerin %24u (n=9) cift tarafli dudak damak yarikli, %20si (n=8) izole damak yarikli, %56si (n=22) tek tarafli dudak damak yarikli idi. Cift tarafli dudak damak yarikli bireylerin yas ortalamasi 24.33±24.69 gun, izole damak yarikli bireylerin yas ortalamasi 68.37±58.04 gun, tek tarafli dudak damak yarikli bireylerin yas ortalamasi ise 31±30.11 gundu. Cift tarafli dudak damak yarikli bireylerin %66.7si (n=6) erkekti. Grubun anterior yarik genisligi ortalama olarak 13.23±3.06, midpalatal genisligi 32.67±3.58, postpalatal genisligi 29.25±2.78 mm idi. Izole damak yarikli bireylerin %37.5’i (3kisi) erkekti. Grubun anterior yarik genisligi bulunmamaktaydi. Midpalatal yarik genisligi 30.71±2.11, postpalatal genisligi 27.17±2.42 mm idi. Unilateral yarikli bireylerin %54.5i (12kisi) erkekti. Grubun anterior yarik genisligi 10.14±3.12, midpalatal genislik 35.74±3.05, postpalatal genislik ise 31.35±3.22 mm idi. Sonuc: Tek ve cift tarafli dudak damak yariklari erkeklerde, izole damak yariklari ise kizlarda daha cok goruldu. Anterior yarik genisligi miktari cift tarafli dudak damak yarikli grupta tek tarafli dudak damak yarikli gruptan daha fazla oldugu goruldu. Ancak midpalatal genisligin ve posterior palatal genisligin tek tarafli dudak damak yarikli bireylerde daha fazla oldugu goruldu. Klinigimize en erken basvuran grubun cift tarafli dudak damak yarikli bireyler, en gec basvuran grubun ise izole damak yarikli bireyler oldugu tespit edildi. Klinigimize basvuran, gerek Hotz plagi gerek nazal molding aygitlariyla tedavilerine baslanan hastalarin uzun donem takiplerinin yapilarak baslangic degerleriyle karsilastirilmasi dusunuldu.

Comparison of the effects of different retention appliances on the oxidant–antioxidant system

Abstract The aim was to compare oxidative stress (OS) levels with different types of retention appliance. Thirty orthodontic patients were divided into three groups: Group 1 (Essix retainer), Group 2 (lingual retainer with stainless steel retainer wire), and Group 3 (lingual retainer with fiber-reinforced material). OS was assessed in the subjects’ saliva. Saliva samples were taken from the patients at T0 (before using the retention appliance), T1 (first month of retention), and T2 (third month of retention). The specimens were investigated to detect changes in total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI). TAS values in Group 2 were significantly higher than in Group 3. TOS values in Group 3 were significantly lower than in the other groups. TOS values in Group 2 were lower than in Group 1. OSI values of Group 1 were higher than those in Group 2 or 3. There was no statistically significant difference among the time periods. The type of retention appliance affected OS values. A fiber-reinforced material may have a lower OSI. OS or products can affect some systemic disease; therefore, the selection of the retainer will be important on these patients.

Cephalometric comparison of cesarean and normal births.

Objective: The aim of this study was to compare cephalometric variables of subjects with normal and cesarean births. Materials and Methods: Ninety age- and gender-matched patients, who were treated in Gaziantep University, Faculty of Dentistry Orthodontics Department were equally divided into normal and cesarean groups according to the birth methods reported by their mothers. To eliminate the negative effects of being different in terms of age and gender among parameters, control, and patient groups were matched in the present study. Pretreatment cephalometrics radiographs were used. Six measurements representing sagittal and vertical relationships were evaluated from pretreatment cephalograms using Dolphin Imaging Orthodontics Software was used in this issue by an orthodontist. Kolmogorov–Smirnov test, Students t-test, and Mann–Whitney U-test were used for statistical comparisons. Results: A point-nasion-B point angle (ANB) and Wits values were higher in the normal group, while sella-nasion-A point angle, sella-nasion-B point angle, Frankfort horizontal-mandibular plane angle, and gonion-gnathion-SN plane angle values were higher in the cesarean group. However, the groups showed no significant differences (P > 0.05). ANB angle and Wits values showed high correlation. Conclusions: Within the study limitations, the results suggest that the birth method may not have a considerable effect on the development of the craniofacial skeletal system.

Can Initial Torque Value Predict the Success of Orthodontic Mini-Screws?

ABSTRACT Objective: To investigate the correlation between initial torque and removal torque of orthodontic mini-screws. Materials and Method: Sixty-four orthodontic mini-screws (measuring 1.5 × 4.4 mm, 1.6 × 4.7 mm, 1.7 × 5.5 mm, and 1.8 × 5.6 mm) were used. All mini-screws were inserted into the fibulas of 8 male rabbits. The initial torque values were immediately recorded using a digital torque gauge. For 2 months, 115 g force was applied to mini-screws inserted into the right fibula of the rabbits. The same procedure was followed for inserting the mini-screws into the left fibula of the rabbits but without applying any force. After 2 months, the removal torque values were recorded for all mini-screws. All statistical analyses were performed using SPSS version 14.0 for Windows. Spearmans correlation coefficient was used to analyze the relationships between initial and removal torque values. Results: Intragroup comparison of all brands of mini-screws showed similar features. There were no statistically...