Evaluating the ability of dental technician students and graduate dentists to match tooth color.

STATEMENT OF PROBLEM: The ability of dental technician students to match tooth shade with the Vita 3D-Master shade guide and Toothguide Training Box has not been investigated. PURPOSE: The purpose of this study was to evaluate and compare the shade-matching ability of dental technician students and graduate dentists using the Vita 3D-Master shade guide. MATERIAL AND METHODS: Twenty-nine dental technician students (DTS group) and 30 graduate dentists (GD group) participated in this study. The Toothguide Training Box (TTB) was used to train the participants and test their shade-matching abilities. Shade-matching ability was evaluated with 3 exercises and a final test, all of which are components of the TTB. The number of mistakes for each participant for value (L), chroma (c), and hue (h) were recorded during the exercises and the final test, and the mistake ratios were calculated. Color difference (ΔE) values for each shade were calculated from the L*, a*, and b* values of the Vita 3D-Master shade guide for each participant in both groups. The Mann-Whitney U test was used to determine statistically significant differences between the L, c, and h mistake ratios of the 2 groups, and the Student t test was used to determine statistically significant differences between the final test scores and the ΔE values of the groups (α=.05). RESULTS: The mistake ratio for L in the GD group was significantly higher than that of the DTS group (P<.05), whereas the mistake ratio for h in the DTS group was higher (P<.001). No significant differences were observed between the groups regarding the mistake ratios for c (P>.05). With regard to the final test scores and the ΔE values, no significant differences were found between the groups (P<.001), and the DTS group received higher scores than the GD group (912 and 851). The mean ΔE values for the DTS and GD groups were 1.72 and 2.92. CONCLUSIONS: DTSs made more mistakes in the h parameter than GDs, and GDs made more mistakes in the L parameter than DTSs. With regard to the final test scores and the ΔE values, DTSs were more successful in shade matching than GDs.

Orthodontic treatment of a transmigrated mandibular canine: a case report.

BACKGROUND: Intraosseous migration of a lower canine across the midline is a rare dental anomaly. The treatment options include: forced eruption of the unerupted tooth using orthodontic traction, autotransplantation, extraction followed by prosthetic replacement. AIM: To report the management of a transmigrated lower right canine. METHOD: The treatment involved surgical, orthodontic and cosmetic dental treatment. No permanent teeth were extracted. RESULTS: The transmigrated canine was placed between the left central and lateral incisors and the crown recontoured to simulate a lateral incisor. An acceptable aesthetic and functional outcome was gained. CONCLUSION: Transmigration is a rare dental condition that can be treated successfully with a collaborative effort from several dental disciplines.

Plant extract ankaferd blood stopper effect on bond strength.

OBJECTIVE: To determine the effect of Ankaferd Blood Stopper (ABS) on the shear bond strength (SBS) of orthodontic attachments. MATERIALS AND METHODS: The study material consisted of 60 freshly extracted bovine permanent mandibular incisor teeth. All teeth were cleaned and randomly divided into three groups of 20 specimens and etched with 37% phosphoric acid for 15 seconds, washed, and air-dried. Teeth in groups 1 and 2 were contaminated with ABS and blood, respectively. Teeth in group 3 were only air-dried. Roth Generous maxillary central incisor brackets were bonded with Transbond XT to all teeth. SBS was applied using a universal test machine. The one-way analysis of variance (ANOVA) test was used to determine significant differences in SBS between the three groups, and Tukey honestly significant post hoc test was used to compare subgroups. RESULTS: The mean bond strengths and standard deviations of groups 1, 2, and 3 were 9.58 +/- 0.95, 4.04 +/- 0.69, and 19.56 +/- 1.84 MPa, respectively. CONCLUSIONS: Specimens contaminated with blood showed a statistically significant lower in vitro SBS than those contaminated with ABS. ABS may be used clinically for obtaining a blood-free tooth surface during application of the brackets on surgically exposed, impacted teeth.

Enamel colour changes at debonding and after finishing procedures using five different adhesives.

The purpose of this study was to evaluate enamel colour alteration of five different orthodontic bonding adhesives by means of digital measurements after exposure to photoageing in order to simulate discolouration of adhesives in vivo. Seventy-five non-carious premolars were randomly divided into five equal groups. The brackets were bonded with five different adhesives (Transbond XT, Eagle Bond, Light Bond, Blugloo, Unite) and subjected to artificial accelerated photoageing for 24 hours. The enamel surfaces were colourimetrically evaluated before bonding, following debonding and cleaning with a tungsten carbide bur, after polishing with Stainbuster, and after photoageing of the debonded enamel surface. The Commission Internationale de l'Eclairage(CIE) colour parameters (L*a*b*) were recorded and colour differences (DeltaE) were calculated. The results were statistically analyzed using the Kruskall-Wallis test. Further investigation among subgroups was performed using Dunn's multiple correlation test (P < 0.05). The clinical detection threshold for DeltaE value was set at 3.7 units. DeltaE values between the first and second measurements showed an increase in the Transbond XT, Eagle Bond, and Light Bond groups. The highest DeltaE value was 1.51 +/- 1.15 in the Transbond XT group. No clinically significant DeltaE value was observed. Colour changes of orthodontic bonding systems induced by photoageing cannot be clinically observed. Polishing with Stainbuster eliminates enamel surface roughness, which may improve light reflection.

Effects of different silanes and acid concentrations on bond strength of brackets to porcelain surfaces.

The aim of this study was to determine the optimum silane-coupling agent and the optimum concentration of acid agent when bonding to porcelain surfaces. Eighty deglazed feldspathic porcelain discs with a diameter of 10 mm and a thickness of 2 mm mounted in acrylic resin blocks were randomly divided into four groups. In groups 1 and 2, the porcelain surfaces were etched with 9.6 per cent hydrofluoric (HF) acid and in groups 3 and 4 with 5 per cent HF acid. In groups 1 and 3, the Dynalock maxillary central incisor brackets were bonded with Pulpdent silane and Unite bonding adhesive and in groups 2 and 4 with Reliance silane and Unite. Shear forces were applied to the samples using an Instron universal test machine. The non-parametric Kruskal-Wallis test was used to determine significant differences in bond strengths between the four groups and Dunn's multiple comparison test to compare subgroups. The mean bond strengths and standard deviations of groups 1 to 4 were 5.51 +/- 1.19, 6.54 +/- 0.002, 4.55 +/- 1.93, and 6.39 +/- 0.45 MPa, respectively. Specimens bonded with Reliance showed a statistically significantly higher in vitro bond strength than those bonded with Pulpdent. The concentration of etching gels did not result in any statistically significant difference on the in vitro bond strength when evaluated separately.

Conscious hypnosis as a method for patient motivation in cervical headgear wear--a pilot study.

The aim of the present study was to assess the efficiency of conscious hypnosis on patient cooperation. The subjects were 30 patients (14 females and 16 males) with a skeletal Class II division 1 malocclusion, divided into two equal groups, a control and a study group. The mean age was 10.78 +/- 1.06 years for the hypnosis, and 10.07 +/- 1.09 years for the control group. Both groups were treated with cervical headgear containing a timer module. The patients were also asked to record their actual wear time on timetables. The hypnosis group patients were motivated with conscious hypnosis while the control group were given verbal motivation by their orthodontist. The timer modules were read at every visit and compared with the timetables. Analysis of variance was used to determine the differences in measurements at each time point. For comparison of the groups, an independent t-test was used. A statistically significant decrease (P < 0.05) in headgear wear was observed in the control group from the first to the sixth month; however, the difference in the hypnosis group was not significant. This result indicates that conscious hypnosis is an effective method for improving orthodontic patient cooperation. There was a low correlation between actual headgear wear indicated by the patient and that recorded by the timing modules, which showed that, timetables are not consistent tools for measuring patient cooperation.

An evaluation of the errors in cephalometric measurements on scanned cephalometric images and conventional tracings.

The aim of this investigation was to compare the classic method of tracing by hand with a computerized method, where the lateral cephalograms were scanned at 300 dpi and digitized onscreen. The inter- and intra-observer errors were investigated for tracing and digitizing errors. Thirty lateral cephalograms were scanned into digital format at 300 dpi, displayed on a high-resolution monitor, and processed twice by two operators using Dolphin Imaging Software 9.0. The same radiographs were then traced and measured manually by the same two operators. Intraclass correlation coefficients (ICC) were used for detecting intra- and inter-rater agreement for each cephalometric variable. The results showed that each operator was consistent in the repeated measurements; all ICC were greater than or equal to 0.90 and none of the 95 per cent confidence limits on these ICC had a lower boundary less than 0.84. Inter-rater agreement also showed correlation coefficients greater than 0.75. The angles, maxillary height, maxillary depth, y-axis, FMA, and nasolabial, and the distance N perpendicular point A had a wider reliability interval and lower correlation than the other parameters tested. The findings demonstrated that the use of computer software for cephalometric analysis carried out on scanned images does not increase the measurement error when compared with hand tracing.