The Impact of Different Types of Orthodontic Appliances and Its Location in Producing CT Scan Artefacts

Fixed orthodontic appliances can produce metal artefacts in CT images which may degrade the diagnostic image quality. The study aimed to evaluate the artefacts based on the types and location of the metallic and non-metallic orthodontic brackets. This is an in-vitro cross-sectional study. Four different types of orthodontic brackets (stainless steel, titanium, monocrystalline, and polycrystalline ceramic bracket) were bonded consecutively in four different locations of the cadaveric skull. All scans were performed by a single operator using the same CT machine followed by a standard scanning protocol. Artefact intensity for all data sets was quantified by calculating the standard deviation (SD) of the grey values within the dataset by following a standard method. The One-way ANOVA Bonferroni test was used for the data analysis. The mean artefact score of the stainless steel bracket was significantly (p < 0.001) high in comparison with other types of the orthodontic brackets. Besides, the mean artefact score was significantly (p=0.002) low when orthodontic brackets were placed unilaterally. Stainless steel brackets produced a significant amount of noise in CT images which can degrade the diagnostic image quality. Thus, the polycrystalline ceramic bracket can be a better alternative of stainless steel brackets for patient need frequent CT scan.

Safe Debonding of Fixed Appliances: A Comparison of Traditional Techniques and LODI Devices on Different Bracket Types in Terms of Enamel Cracks, Site of Bond Failure, and Bracket Reusability

The objective of this study was to compare the effects of the debonding of three different bracket types by means of three popular debonding methods. A total of 180 human third molars was divided into six groups, consisting of 20 teeth each. Three bracket types were bonded to the enamel (metal brackets with an integral base and a foil mesh base, and ceramic brackets) and three methods of bracket debonding were employed (bracket removal pliers, Weingart pliers, and Lift-Off Debonding Instrument). The samples were examined with scanning electron microscopy to assess the number of enamel cracks, measure the area of adhesive remaining on the enamel, and calculate the adhesive remnant index (ARI). There were no statistically significant differences between the groups in terms of the number of enamel cracks after bracket debonding. The amount of adhesive remaining on the teeth after the brackets were removed was significantly different between the groups. LODI and Weingart pliers are considered to be the safest methods of debonding brackets with an integral base, while LODI is the best tool for brackets with foil mesh. Bracket removal pliers are considered to be the preferred method for ceramic bracket debonding.

Non-Invasive Optical Coherence Tomography Data-Based Quantitative Algorithm for the Assessment of Residual Adhesive on Bracket-Removed Dental Surface

The aim of this study was to quantitatively assess the residual adhesive on orthodontic ceramic bracket-removed dental surface. In orthodontic process, ceramic bracket was repeated debonding physically, then the adhesive remained on the dental surface. The residual adhesive caused a lack of adhesive strength between dental and ceramic bracket. Since commonly used adhesive in orthodontics is translucent, residual adhesive is hard to be detected with conventional microscopes. Therefore, 1310 nm center wavelength swept-source OCT system based on laboratory customized image processing algorithm was used for the precise detection of residual adhesive on tooth surface. The algorithm separates residual adhesive from dental surface by comparing the height of adjacent B-scan images, while providing color-scaled images emphasizing the thickness information of residual adhesive. Finally, the acquired results were compared with microscopic and adhesive remnant index scoring gold standards, while the comparison confirmed the potential merits and the improvements of the proposed method over gold standards.

Surface Electromyography (sEMG) Activity of Masticatory Muscle (Masseter and Temporalis) with Three Different Types of Orthodontic Bracket

Objective. This pre-post study is aimed at determining the effects of masticatory muscle activity (masseter and temporalis) measured via sEMG between conventional, self-ligating, and ceramic bracket after six months of orthodontic treatment. Methods. A total of eighteen (18) malocclusion patients were identified. Malocclusion patients were subdivided into 3 groups based on the bracket selection (conventional, self-ligating, and ceramic bracket) with 6 patients for each group. sEMG of muscles were done using a two-channel electromyography device, where pregelled and self-adhesive electrodes (bilateral) were applied. Chewing and clenching of masseter and temporalis muscle activity were recorded for 20 s pre and 6 months of orthodontic treatment using sEMG (frequency 60 Hz). The data were analysed by using repeated measures ANOVA in IBM SPSS Statistics Version 24.0. Results. Chewing and clenching for masseter muscle showed no significant difference ( P > 0.05 ) in sEMG activity of three types of the brackets. However, for temporalis muscle, there was a significant difference found in sEMG activity during chewing ( P < 0.05 ) and clenching ( P < 0.05 ) between these three brackets. Conclusion. The activity of temporalis muscle showed significant changes in chewing and clenching, where the conventional group demonstrated better muscle activity pre and at six months of fixed appliances.

CO2 laser irradiation for debonding ceramic orthodontic brackets

This study evaluated shear bond strength (SBS), adhesive remnant index (ARI) and fracture mode of chemically and mechanically retained ceramic brackets bonded with different composite resins and irradiated with CO2 laser. The null hypothesis was that ceramic brackets bonded with different composite resins and irradiated with CO2 laser would have similar SBS values. Ninety human premolars were divided into four experimental groups according to the combination of type of composite resin (Transbond XT and Z 250) and type of ceramic bracket (Fascination and Mystique), and two control groups (n=15). In the four experimental groups, the brackets were irradiated with CO2 laser at 10 W for 3 seconds before SBS testing. Enamel surface ARI was calculated after debonding under electron microscopy scanning. ANOVA and the Mann-Whitney test were used for statistical analysis. The laser groups had lower SBS values than the non-irradiated groups (control) (p<0.05). The mechanically retained brackets (Mystique) had the higher (p<0.05) and Z250 had the lower SBS values after CO2 laser irradiation. The groups bonded with Z250 had the highest ARI. Adhesive fractures were the most prevalent. The null hypothesis was rejected. CO2 laser decreased SBS efficiently and facilitated debonding of mechanically and chemically retained ceramic brackets.

Pengaruh Kloroform Terhadap Pelarutan Bahan Perekat Yang Menempel Pada Braket Keramik Yang Lepas Dari Gigi

ABSTRAK Kebutuhan braket transparan pada perawatan ortodonti semakin berkembang dengan adanya kebutuhan braket sewarna gigi, terutama wanita yang memerlukan penampilan estetik maksimal. Braket yang lepas dalam perawatan ortodonti perlu direkatkan kembali. Pembersihan landasan braket yang terlepas sehingga dapat direkatkan kembali akan mengurangi biaya yang harus dikeluarkan pasien. Melakukan daur ulang braket haruslah dapatdapat dilakukan tanpa merubah sifat fisik dan ukuran dari braket tersebut. Penelitian ini adalah penelitian eksperimental analitik laboratoris in vitro dengan pendekatan komparatif yang bertujuan untuk melihat perbedaan kuat rekat geser braket keramik yang dibersihkan dengan kloroform selama 20 menit, 40 menit, 60 menit. Sampel yang digunakan dalam penelitian ini adalah 60 buah braket keramik monokristalin merek Ice Inspire dari Ormco dengan perlekatan mekanik. Pengukuran uji rekat geser menggunakan Instron Universal Testing Machine dan sisa resin menggunakan skor ARI. Analisis statistik dilakukan dengan uji Wilcoxon dan ANOVA. Hasil penelitian menunjukkan terdapat perbedaan bermakna kuat rekat geser braket keramik pasca rekat yang dibersihkan dengan kloroform selama 20 menit, 40 menit, 60 menit dan braket keramik pascarekat yang baru. Simpulan dari penelitian ini bahwa Terdapat perbedaan kuat rekat geser braket keramik yang dibersihkan dengan kloroform selama 20 menit, 40 menit, 60 menit dengan braket keramik yang baru, Semakin lama waktu pembersihan braket keramik dengan kloroform, sisa resin adhesif akan semakin bersih dan mempunyai kuat rekat geser yang lebih tinggi. Terdapat perbedaan sisa resin adesif antara braket keramik pasca rekat yang dibersihkan dengan kloroform yang dilepas kembali dengan braket keramik pasca rekat yang baru. Kata Kunci : perbedaan kuat rekat geser, kloroform, kuat rekat geser, ARI, braket keramik. ABSTRACT Transparant bracket needs in orthodontic treatment is become huge caused the needs of tranlucent bracket , especially women who require maximum aesthetic appearance. Debonding bracket in orthodontic treatment need to reattached. By Cleaning mesh of bracket so it can be reattached to reduce patient costs . Recycling bracket must can done without changing the physical properties and the size of bracket. This study is an experimental study in vitro analytical comparative approach that aims to see the difference shear strength adhesion to ceramic brackets were cleaned with chloroform for 20 minutes , 40 minutes , 60 minutes . The sample used in this study were 60 pieces of ceramic bracket monokristalin from Ormco Inspire Ice with mechanical retention. Measurement of shear strength test using the Instron Universal Testing Machine and the rest of the resin using ARI scores . Statistical analysis was used with Wilcoxon test and ANOVA . The results showed there were significant differences in the bracket shear strength rebonding ceramic bracket, which cleaned with chloroform for 20 minutes , 40 minutes , 60 minutes and new rebonding ceramic bracket. Conclusions from this research that There is a difference in the shear strength ceramic brackets which cleaned using chloroform for 20 minutes , 40 minutes , 60 minutes and with a new ceramic bracket , the longer time cleaning ceramic bracket with chloroform, the rest of the adhesive resin will be clean and have strong adhesion higher shear. There are differences between the residual resin adhesive after adhesive ceramic bracket cleaned with chloroform is released back and the ceramic new bracket rebonding. Key words :

Bond Strength of Metallic or Ceramic Orthodontic Brackets to Enamel, Acrylic, or Porcelain Surfaces

Bonding strategies within different brackets and dental materials are still a challenge concerning adhesion and dental surface damage. This study compared the shear and tensile bond strength of orthodontic ceramic and metallic brackets to enamel, acrylic, and ceramic surfaces after thermal cycling. Dental surfaces were divided into three groups: enamel, ceramic, and acrylic. Each group received stainless-steel and ceramic brackets. After thermal cycling, specimens were randomly divided into two subgroups considering tensile (TBS) or shear bond strength (SBS) test. After the mechanical testing, scanning electron and optical microscopy were performed, and the adhesive remnant index (ARI) was determined. The two-way ANOVA full factorial design was used to compare TBS, SBS, and ARI on the surface and bracket type (α = 0.05). There were significant differences in TBS, SBS, and ARI values per surface (p < 0.001 and p = 0.009) and type of bracket (p = 0.025 and p = 0.001). The highest mean SBS values were recorded for a ceramic bracket bonded to an acrylic surface (8.4 ± 2.3 MPa). For TBS, a ceramic bracket bonded to acrylic showed the worst performance (5.2 ± 1.8 MPa) and the highest values were found on a metallic bracket bonded to enamel. The adhesion of metallic or ceramic brackets is enough for clinical practice although the damage of the enamel surface after debonding is irreversible and harmful for the aesthetic outcome of the teeth.

In vitro testing of shear bond strength of orthodontic brackets bonded to different novel CAD/CAM ceramics

Background. The present study aimed to evaluate the bond strength of metal bracket (MB) and ceramic bracket (CB) bonded to different CAD/CAM ceramic substrates etched with hydrofluoric acid (HFA) vs. phosphoric acid (PA). Methods. A total of 120 CAD/CAM ceramic blocks in 12 groups were fabricated from three different CAD/CAM ceramic materials: VITABLOCS Mark II, VITAENAMIC, and IPS e.max CAD. Each ceramic material group was divided into two etching groups: one treated with 9.5% HFA and the other treated with 37%. Sixty metal and CBs of the upper right central incisor were bonded to the HFA-treated blocks. Another 60 metal and CBs were bonded to the PA treated blocks. All the bonded specimens were thermocycled before shear bond strength (SBS) testing. Then the bond failure mode was recorded Results. There were no significant differences in SBS values between the three CAD/CAM ceramic materials. The HFA-treated specimens exhibited significantly higher SBS values than the PA-treated specimens. Also, the SBS values of CBs were significantly higher than the metal brackets (MBs). The adhesive remnant index (ARI) score was 4 for most of the groups, indicating that almost no adhesive remained on the porcelain surface. Conclusion. The CAD/CAM ceramic type did not influence SBS; however, HFA exhibited significantly higher SBS compared to PA.