Enamel Surface Research Articles

Enamel changes of bleached teeth following application of an experimental combination of chitosan-bioactive glass

BackgroundConsidering the extensive use of bleaching agents and the occurrence of side effects such as enamel demineralization, this study aimed to assess the enamel changes of bleached teeth following the experimental application of chitosan-bioactive glass (CH-BG).MethodsIn this in vitro study, CH-BG (containing 66% BG) was synthesized and characterized by Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Thirty sound human premolars were bleached with 40% hydrogen peroxide, and the weight% of calcium and phosphorus elements of the buccal enamel surface was quantified before and after bleaching by scanning electron microscopy/ energy-dispersive X-ray spectroscopy (SEM, EDX). Depending on the surface treatment of the enamel surface, the specimens were divided into three groups (n = 10): control (no treatment), MI Paste (MI), and CH-BG. Then the specimens were stored in artificial saliva for 14 days. The SEM/EDX analyses were performed again on the enamel surface. Data were analyzed by one-way ANOVA and Tukey’s test and a p-value of < 0.05 was considered statistically significant.ResultsIn all groups, the weight% of calcium and phosphorus elements of enamel decreased after bleaching; this reduction was significant for phosphorus (p < 0.05) and insignificant for calcium (p > 0.05). After 14 days of remineralization, the weight% of both calcium and phosphorus elements was significantly higher compared to their bleached counterparts in both MI and CH-BG groups (p < 0.05). Following the remineralization process, the difference between MI and CH-BG groups was not significant (p > 0.05) but both had a significant difference with the control group in this regard (p < 0.05).ConclusionsThe synthesized CH-BG compound showed an efficacy comparable to that of MI Paste for enamel remineralization of bleached teeth.

Correction to: Effect of femtosecond and ER:YAG laser systems on shear bond strength of enamel surface and morphological changes

Correction to: Effect of femtosecond and ER:YAG laser systems on shear bond strength of enamel surface and morphological changes

Safety and Efficacy of the Erbium Laser in Debonding Dental Accessories: A Narrative Review.

Objective: This article aims to review the safety and efficacy of the Er:YAG laser in debonding dental accessories. Methods: This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Articles published between 2010 and 2022 on the removal of dental accessories using erbium laser were searched. The selected articles were then classified according to the accessories used: adhesives, brackets, restorations, or implant crowns. Enamel surface roughness, shear bond strength, adhesive remnant index, duration time (t), pulp chamber temperature (T), morphology (M), and other variables were then noted. Results: The dental accessories and adhesives used were described along with the laser parameters used, such as frequency, pulse width, irradiation time, scanning mode, water-air cooling, and other variables. Conclusions: Laser removal using Er:YAG laser of dental accessories such as brackets, crowns, and veneers is fundamentally safe, time-saving, and does not cause damage to the enamel nor the underlying dentin. However, there was no distinct advantage with laser removal seen, such as those residual adhesives of brackets on the tooth surface and temporary adhesives of restorations.

Formulation of arginine-loaded mesoporous silica nanoparticles (Arg@MSNs) modified orthodontic adhesive

ObjectivesThe objective of this study was to synthesize arginine loaded mesoporous silica nanoparticles (Arg@MSNs), develop a novel orthodontic adhesive using Arg@MSNs as modifiers, and investigate the adhesive performance, antibacterial activity, and biocompatibility. MethodsArg@MSNs were synthesized by immobilizing arginine into MSNs and characterized using transmission electron microscope (TEM), dynamic light scattering (DLS), and Fourier Transform Infrared Spectrometer (FT-IR). Arg@MSNs were incorporated into Transbond XT adhesive with different mass fraction to form functional adhesives. The degree of conversion (DC), arginine release behavior, adhesive performance, antibacterial activity against Streptococcus mutans biofilm, and cytotoxicity were comprehensively evaluated. ResultsTEM, DLS, and FT-IR characterizations confirmed the successful preparation of Arg@MSNs. The incorporation of Arg@MSNs did not significantly affect DC and exhibited clinically acceptable bonding strength. Compared to the commercial control, the Arg@MSNs modified adhesives greatly suppressed the metabolic activity and polysaccharide production while increased the biofilm pH values. The cell counting kit (CCK)-8 test indicated no cytotoxicity. ConclusionsThe novel orthodontic adhesive containing Arg@MSNs exhibited significantly enhanced antibacterial activities and inhibitory effects on acid production compared to the commercial adhesive without compromising their bonding strength or biocompatibility. Clinical significanceThe novel orthodontic adhesive containing Arg@MSNs exhibits potential clinical benefits in preventing demineralization of enamel surfaces around or beneath orthodontic brackets due to its enhanced antibacterial activities and acid-producing inhibitory effects.

Rapid Deposition of the Biomimetic Hydroxyapatite-Polydopamine-Amino Acid Composite Layers onto the Natural Enamel.

In this work, we developed a technology that enables rapid deposition of biomimetic composite films onto natural enamel slices (known as biotemplates). These films are composed of polydopamine (PDA) and nanocrystalline carbonate-substituted hydroxyapatite (nano-cHAp) that have been functionalized with amino acid l-Arginine. We utilized atomic force microscopy (AFM) and scattering scanning near-field optical microscopy (s-SNOM) combined with infrared (IR) synchrotron to achieve nanoscale spatial resolution for both IR absorption and topography analyses. This combined analytical modality allowed us to understand how morphology connects to local changes in the chemical environment on the biotemplate surface during the deposition of the bioinspired coating. Our findings revealed that when using the proposed technology and after the deposition of the first PDA layer, the film formed on the enamel surface nearly covers the entire surface of the specimen whose thickness is larger on the surface of the emerging enamel prisms. Calculation of the crystallinity index for the biomimetic layer showed a multiple increase compared with natural enamel. This indicates regular and dense aggregation of nano-cHAp into larger crystals, imitating the morphology of natural enamel rods. The microhardness of the formed PDA-based biomimetic layer mineralized with nano-cHAp functionalized with amino acid l-Arginine deposited on natural enamel was practically the same as that of natural enamel. The characterization of nano-cHAp-amino acid-PDA layers using IR and Raman microspectroscopy showed that l-arginine acts as a conjunction agent in the formation of mineralized biomimetic composite coatings. The uniformity of the mechanisms of PDA layer formation under different deposition conditions and substrate types allows for the formation of coatings regardless of the macro- and micromorphology of the template. Therefore, the results obtained in this work have a high potential for future clinical applications in dental practice.

PENGARUH PERENDAMAN AIR PDAM TERHADAP KEKERASAN ENAMEL GIGI PASKA HOME BLEACHING KARBAMID PEROKSIDA 20%

Background: One of the treatments to overcome the problem of discolored teeth is to do tooth whitening or bleaching. The tooth whitening agent that is often used is carbamide peroxide which is applied directly to the tooth enamel surface. Several factors that can affect tooth enamel are the degree of acidity or potential hydrogen (pH), acid concentration, dissolving time and the presence of calcium-like ions. Communities in Banjarmasin City still frequently use PDAM water for consumption and for their daily needs. Objective: To analyze the effect of immersing PDAM water and distilled water on the hardness of tooth enamel after the application of 20% carbamide peroxide. Methods: This study used a true experimental method with a posttest-only with control group design consisting of 4 treatment groups namely positive control PDAM water, negative control Aquatic water, group 1 carbamide peroxide 20% and PDAM water, and group 2 carbamide peroxide 20% and distilled water. Tooth enamel hardness was measured using a Vickers microhardness tester. Results: analysis of the One Way Anova test with Post-Hoc Bonferroni showed that there was a significant difference in violence in each group (p&gt;0.05). Conclusion: There is an effect of PDAM water after application of 20% carbamide peroxide on the hardness of enamel on teeth.Keywords: Carbamide Peroxide 20%, Discolored, Enamel Hardness, PDAM

PENGARUH PERENDAMAN AIR PDAM BANDARMASIH TERHADAP KEKASARAN PERMUKAAN GIGI PASCA PENGAPLIKASIAN KARBAMID PEROKSIDA 20%

Background: One of the treatments to overcome the problem of discolored teeth is to do tooth whitening or bleaching. The tooth whitening agent that is often used is carbamide peroxide which is applied directly to the tooth enamel surface. Several factors that can affect tooth enamel are the degree of acidity or potential hydrogen (pH), acid concentration, dissolving time and the presence of calcium-like ions, and the level of water hardness. Most of the people in Banjarmasin City still frequently use PDAM water as drinking water and for daily use Objective: To analyze the effect of immersing PDAM water and distilled water on tooth surface roughness after application of 20% carbamide peroxide. Methods: Using a pure experimental design with the Posttest Only With Control Group Design and simple random sampling technique. The total sample was 16 maxillary first premolars which were divided into 3 treatment groups and 1 control group. Results: analysis of the One Way Anova test with Bonferroni's Post-Hoc showed no difference in roughness between the PDAM water immersion and distilled water groups with or without the application of 20% carbamide peroxide (p&gt;0.05). There was a difference in roughness between the group that was given carbamide peroxide and the group that was not given carbamide peroxide 20% (p&lt;0.05). Conclusion: There is an effect of PDAM water immersion on tooth surface roughness after application of 20% carbamide peroxide, but the resulting roughness is not significant.Keywords: PDAM water, Tooth Surface Roughness, 20% Carbamide Peroxide

Evaluating the Effect of Different Mouthrinses on Properties of the Enamel and Dental Composite Surfaces

This study investigated the effects of different solutions (artificial saliva, Listerine Cool Mint-alcohol containing and Colgate Plax-alcohol free) on the nanohardness, elastic modulus and surface roughness of enamel surface and composite materials (Admira Fusion, Clearfil Majesty Esthetic and Mosaic Universal). Specimens of 2 mm depth and 5 mm diameter were stored in solutions for 12 h at 37�C. Baseline and final measurements were obtained using a HYSITRON TI 950 TriboIndenter testing machine. The applied force to each specimen increased from 0 to 1000 �N. For SEM images, one sample in each group was covered with a thin layer of mix of gold and palladium using a sputter coater (Quorum Q150R ES, UK). Scanning electron microscopy (SEM) images were taken at 5000� magnifications to evaluate the surface morphology. Statistical analysis for hardness, elastic modulus and roughness was performed by Two-way ANOVA, Benferroni and Tukey HSD at a significance level 0.05. The results of this study showed that the highest value of surface roughness and lowest hardness and elastic modulus were presented by Admira (p[0.001). Listerine caused significantly increased surface roughness (p[0.001) and decreased hardness and elastic modulus parameters (p[0.001). The mouthrinse containing alcohol caused more significant changes in the nanohardness, elastic modulus, surface roughness values of enamel and composite surfaces.

Evaluation of the effects of different mouthwashes, acidic soft drinks, and herbal teas on shear bond strength of orthodontic stainless steel brackets: A stereomicroscopic study

Background: Premature debonding of brackets often turns out into orthodontic treatment failures and actual treatment delays. The aim of the present study was to evaluate the effects of different mouthwashes, acidic soft drinks, and herbal teas on the shear bond strength of metal (stainless steel) brackets used in orthodontic practice. Materials and methods: For the present study, 100 therapeutically extracted healthy premolar teeth with sound enamel surface were collected from patients who were scheduled for orthodontic treatment. The select teeth were cleansed, whereas the dried enamel surface was etched with 38% phosphoric acid for 15 s following which orthodontic stainless steel brackets (MBT 0.022 SLOT) were bonded with the help of composite resin (3M Unitek Transbond XT Light Cure Adhesive). The prepared teeth were divided into four groups depending on exposure to different mouthwashes, acidic soft drinks, and herbal teas. The shear bond strength values of the specimen were measured using a universal testing machine, whereas debonded surfaces were observed under a stereomicroscope. Statistical analysis was done using the Statistical Package for the Social Sciences (SPSS) version 18.0 (SPSS Inc., Chicago, IL, USA). One-way analysis of variance and Tukey’s multiple post hoc procedures were used for statistical analysis. P &lt;0.05 was considered statistically significant. Results: The results obtained in the present study suggested that the highest mean shear bond strength observed was in case of Group II specimen with a mean value of 11.83 ± 1.92 MPa, whereas the least shear bond strength was observed in case of Group III specimen with a mean value of 10.33 ± 1.31 MPa, with the results being statistically significant (P = 0.014). Conclusions: Within the limitations of the present study, it was concluded that comparatively lesser/weaker shear bond strength values were observed in case of specimen belonging to Group III, wherein among the 30 teeth belonging to Group III, 12 teeth showed shear bond strength value of 9 MPa which was the lowest in the study. The following core competencies are addressed in this article: Practice-based learning and improvement, Patient care and procedural skills, Systems-based practice, Medical knowledge.

Comparative Evaluation of Remineralizing Potential of Topical Cream Containing Casein Phosphopeptide-Amorphous Calcium Phosphate and Casein Phosphopeptide-Amorphous Calcium Phosphate with Fluoride: An In Vitro Study

ABSTRACT The requirement for clinically effective treatments to remineralize early enamel caries lesions is dictated by the principles of minimally invasive dentistry. Numerous studies outlined the significance of treating early carious lesions with different remineralizing agents. This study aimed to evaluate and compare the remineralization potential of topical cream containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and CPP-ACP with fluoride in remineralizing artificial carious lesions on enamel. Forty-five freshly extracted human premolar teeth were selected as samples. These samples were divided into three groups: Group I-regular toothpaste without specific remineralizing agent; Group II-topical cream containing CPP-ACP and Group III topical cream containing CPP-ACP with fluoride. All the samples were viewed under scanning electron microscope (SEM) to assess the topographical pictures of the enamel surface and also subjected to energy dispersing X-ray analysis (EDX) for quantitative estimation of minerals, calcium (Ca), and phosphorous (P). In the result of the study, Group I does not show any increase in the Ca and P after applying toothpaste without any remineralizing agent but Group II and Group III showed a net increase in Ca and P- values after applying concerned remineralizing agents. Intergroup comparison showed Group III yielded higher net Ca and P- values than Group II. Two remineralizing agents showed remineralization potential on samples. Descriptive statistics were used to calculate the mean and standard deviation. Mann–Whitney test was used. The level of significance was set at 0.05. CPP-ACP containing fluoride showed better remineralizing potential than CPP-ACP. Hence, CPP-ACP containing fluoride can be considered the material of choice in remineralizing early enamel carious lesions.

Effect of different activation techniques of two in-office bleaching systems on color change of enamel surface: An in-vitro study

Effect of different activation techniques of two in-office bleaching systems on color change of enamel surface: An in-vitro study

Comparative Evaluation of Various Antioxidants on the Shear Bond Strength of Composite Resin to Bleached Enamel - An In Vitro Study.

To evaluate and compare the effect of various antioxidants on the shear bond strength of composite resin to bleached enamel. Labial enamel surfaces of 90 extracted human maxillary central incisors were randomly divided into five groups based on the antioxidant used as follows: Group I ( n = 20): Bleaching with 40% hydrogen peroxide gel for 10 min, without the use of an antioxidant; Group II ( n = 20): Bleaching followed by the use of 10% sodium ascorbate solution; Group III ( n = 20): Bleaching followed by the use of 5% grape seed extract solution; Group IV ( n =20): Bleaching followed by the use of 5% pine bark extract solution; and Group V ( n =20): Control group in which no bleaching was done. Groups I-IV were further subdivided into two subgroups of 10 teeth each, whether the antioxidant application and composite build-up was done immediately (subgroup A) or after 2 weeks of postbleaching (subgroup B). Shear bond strength of the specimens was tested under a universal testing machine. One-way analysis of variance followed by Mann-Tukey posthoc multiple comparison test was used to analyse the data. The level of significance was established at P < 0.05. Within the limitations of this study, it was observed that the use of antioxidants effectively reversed the compromised bond strength of bleached enamel. Among the antioxidants, 5% pine bark extract application after bleaching showed better bond strength.

EVALUATION OF BOND STRENGTH OF NEWER BONDING AGENTS TO HUMAN DENTIN AFTER SIX MONTHS OF STORAGE AN ANALYTIC STUDY

Introduction: Among various materials, composite resins have been developed in order to provide the best aesthetics to the anterior restorations as well as for posterior restorations. Resin-dentin bonds are more difficult to achieve than resin-enamel bonds, because dentin bonding relies on organic components. Materials &amp; Methodology: A total number of 44 extracted human mandibular premolars were collected. Occlusal enamel surface was removed using an airotor and diamond bur.The collected 44 teeth were divided in to four groups according to the bonding agents used. 1st sub group with five teeth that is submitted for microtensile testing within 24 hours and SEM analysis for failure mode, 2nd sub-group contains five teeth which is submitted to microtensile bond strength after six months of storage in normal saline and thereafter for SEM analysis for failure mode, and the 3rd sub-group with one teeth which is prepared for analyzing the bond interface using SEM Results: Summarized data was presented using Tables. Data was normally distributed as tested using the Shaperio‑Wilk W test (p-value was less than 0.05). Therefore, analysis was performed using the parametric tests i.e. Independentt test (for comparing two groups) and One way Anova test (for comparing more than two groups). Level of statistical significance was set at p-value less than 0.05. Conclusion:The lowest bond strength values both at 24 hours and after 6 months in normal saline due to its solvent system (acetone, ethanol, water), which might not create a stable adhesive layer like other agents. Optimal filler load could also reduce bond strength by limiting resin availability. SEM analysis revealed that fewer resin tags, indicating incomplete penetration into dentinal tubules, resulting in weaker bonding and susceptibility to degradation. Adhesive failures indicating poor adhesion at the dentin interface, while mixed failures suggested inadequate bonding with the composite resin. This underscores the importance of refining bonding agent formulations and application techniques to ensure enduring adhesive bonds in restorative dentistry.

In Vitro Study on the Influence of the Buccal Surface Convexity of the Tooth upon Enamel Loss after Bracket Removal.

Polishing after the removal of brackets is the final step in orthodontic treatment. It is simple to perform, though some studies have reported that polishing causes damage to the enamel surface. An in vitro study was made of the influence of the buccal surface convexity of the tooth upon possible enamel loss when the remaining resin and adhesive are removed after bracket decementing using two different polishing modes: a tungsten carbide bur at low and high speeds. The convexity of the buccal surface was quantified in 30 incisors and 30 premolars. A stereoscopic microscope was used to obtain photographs of the profile of the crown, and Image J software was used to calculate convexity by dividing the length of a line from the cementoenamel junction to the incisal margin by another line from the mentioned junction to the maximum convexity of the buccal surface. Brackets were cemented on all the teeth and were decemented 24 h later. In both groups, the residual composite was removed with a tungsten carbide bur at a low speed in one-half of the teeth and at a high speed in the other half. The buccal surface of each tooth was then photographed again, and the convexity was calculated and compared against the baseline value. The difference between the two values were taken to represent the enamel loss. The convexity of the premolars was significantly greater than that of the incisors, but this did not result in greater enamel loss when the same polishing mode was used. However, the tungsten carbide bur at a high speed proved more aggressive, causing significantly greater enamel loss than when used at a low speed.

Changes in enamel hardness, wear resistance, surface texture, and surface crystal structure with glass ionomer cement containing BioUnion fillers.

This study investigated the potential of BioUnion filler containing glass ionomer cement (GIC) to enhance the properties of enamel surrounding restorations, with a specific focus on the effect on hardness. The hardness of the bovine enamel immersed in the cement was measured using Vickers hardness numbers. Following sliding and impact wear simulations, the enamel facets were examined using confocal-laser-scanning microscopy and scanning-electron microscopy. Surface properties were further analyzed using energy-dispersive X-ray spectroscopy and X-ray diffraction (XRD). A significant increase in Vickers hardness numbers was observed in the BioUnion filler GIC after 2 days. Furthermore, the mean depth of enamel facets treated with BioUnion filler GIC was significantly less than that of untreated facets. Characteristic XRD peaks indicating the presence of hydroxyapatite were also observed. Our findings imply that GIC with BioUnion fillers enhances the mechanical properties of the tooth surface adjacent to the cement.

Study on the effect of crystal changes on acid resistance of erbium laser etched enamel surface.

To investigate the mechanism underlying high acid resistance of enamel after erbium laser etching. Forty-five premolars were collected and assigned to three groups. A 4×4×1 mm enamel sample was prepared, the left side was the control side, the right side was the treated side, which was treated with different surface treatments, including 35% phosphoric acid etching, Er:YAG laser etching, and Er,Cr:YSGG laser etching. The hydroxyapatite crystal size on the enamel surface of the samples was observed. The contents of Ca, P, O, F, Cl, C, Mg were detected. The crystallinity of the hydroxyapatite crystal was analyzed. After erbium laser etching, the enamel surface had high hydroxyapatite crystal size, beneficial content of chemical elements and crystallinity. The morphological and composition changes of crystals in the enamel surface after erbium laser etching may be one of the crucial mechanisms underlying the enhancement of acid resistance of enamel after erbium laser etching.

Aesthetic impact of resin infiltration and its mechanical effect on ceramic bonding for white spot lesions

BackgroundTreating white spot lesions (WSLs) with resin infiltration alone may not be sufficient, raising questions about its compatibility with other treatments amid controversial or incomplete data. Therefore, this study aimed to assess the aesthetic feasibility of resin infiltration combined with bleaching, as well as its potential mechanical effect on ceramic bonding to WSLs.MethodsOne hundred and fifty flat enamel surfaces of bovine incisors were prepared. Ninety specimens were deminerailized and randomly assigned to three groups(n = 30): post-bleaching resin infiltration (Bl-R), pre-bleaching resin infiltration (R-Bl), and only resin infiltration (R). Color, surface roughness and microhardness were assessed in immediate, thermocycling and pigmentation tests. The remaining sixty samples were randomly assigned to three groups (n = 20): control (Ctrl), bonding (Bo), pre-bonding resin infiltration (R-Bo). Shear bonding strength, failure mode, micro-leakage depth and interface morphology were evaluated after ceramic bonding. The Tukey test and analysis of variance (ANOVA) were used for statistical analysis.ResultsFor the effect of resin infiltration and bleaching on WSLs, the R-Bl group showed the worst chromic masking ability, with the highest |ΔL|, |Δa|, |Δb|, and ΔE values after treatment. Compared with those in the Bl-R group, the R-Bl and R groups showed significant time-dependent staining, which is possibly attributed to their surface roughness. For the effect of resin infiltration on the adhesive properties of WSLs, resin infiltration reduced the staining penetration depth of WSLs from 2393.54 ± 1118.86 μm to 188.46 ± 89.96 μm (P < 0.05) while reducing WSLs porosity in SEM observation.ConclusionsPost-bleaching resin infiltration proved to be advantageous in the aesthetic treatment of WSLs. Resin infiltration did not compromise bonding strength but it did reduce microleakage and enhance marginal sealing. Overall, resin infiltration can effectively enhance the chromatic results of treated WSLs and prevent long-term bonding failure between ceramics and enamel. Based on these findings, the use of post-bleaching resin infiltration is recommended, and resin infiltration before ceramic bonding is deemed viable in clinical practice.

Evaluation of enamel surface integrity after orthodontic bracket debonding: comparison of three different system.

This study aimed to evaluate enamel surface integrity and time consumed during residual cement removal after bracket debonding using different adhesive removal burs with and without a dental loupe. Sixty human-extracted premolars were collected, cleaned, mounted, and prepared for orthodontic bracket bonding. Teeth were randomly divided into three main groups (n = 20) based on the adhesive removal method: tungsten carbide system (TC), sof-lex discs system (SD), and diamond system (DB) groups. Then, each group was subdivided into two subgroups (naked eye and magnifying loupe subgroups). The brackets were bonded and then debonded after 24h, and the Adhesive Remnant Index (ARI) was assessed. The adhesive remnants were removed by different systems, and the final polishing was performed by Silicone OneGloss. The enamel surface roughness was evaluated before bracketing (T0), after residual cement removal (T1), and finally after polishing (T2) using surface Mitutoyo SJ-210 profilometry and Scanning Electron Microscopy (SEM) to determine the Enamel Damage Index (EDI) score. The time consumed for adhesive removal was recorded in seconds. The Kruskal Wallis test showed a statistically significant difference in roughness values at T1 compared to T2 between subgroups (p < 0.001). When comparing EDI at T1 and T2, the Kruskal-Wallis H-test showed statistically significant differences in all subgroups. The pairwise comparisons revealed that EDI scores showed a statistically significant difference at T1 and T2 between DB vs. TC and SD (p = 0.015) but not between TC vs. SD (p = 1.000), indicating the highest roughness value observed in the DB group. The time for cement removal was significantly shorter in the magnifying loupe group than in the naked eye group and was shortest with the TC group, whereas the time was the longest with the DB group (p < 0.05). All three systems were clinically satisfactory for residual orthodontic adhesive removal. However, TC system produced the lowest enamel roughness, while the DB system created the greatest. The polishing step created smoother surfaces regardless of the systems used for resin removal.

Evaluation of Enamel Staining Susceptibility after Using Three Kinds of Orthodontic Adhesives and Four Different Clean-Up Techniques

Background: The present study tried to find the proper bonding and debonding technique to preserve the natural enamel surface and avoid its discoloration. Methods: Sixty newly extracted human premolars were randomly divided into three groups, and three orthodontic adhesives were applied to bond the brackets: chemically cured System 1 Plus adhesive (Ormco, USA) (CC), light-cured resin (Transbond XT, 3Munitek, USA) (LC), and resin-modified glass ionomer cement (Fuji Japan) (GI). The specimens were immersed in black tea for one week and debonded, and four prophylactic methods were applied to remove residual resin: 1) tungsten carbide bur (TC), 2) tungsten carbide bur + Sof-Lex polisher (TC + SL), 3) tungsten carbide bur + One Gloss Polisher (TC + OG), and 4) tungsten carbide bur + Po-Go polisher (TC + PG). The enamel color was measured according to the CIE standard system (Commission Internationale de l’Eclairage) by Konica Minolta CS Spectroradiometer equipment twice: 1) natural enamel color before bonding and 2) after bonding, staining, debonding, and polishing. The ΔE value is the tooth discoloration, which is measured from the mean Δa*, Δb*, and ΔL* values using the following formula ΔE = [(ΔL*)2 + (Δa*)2 + (Δb*)2]1/2 for each group. Then, it was statistically analyzed using a t-test. Results and Conclusions: Regarding adhesive materials, CC adhesive showed higher discoloration than LC in all the polishing methods. The lowest discoloration was observed in GI. The highest ΔE* values were obtained using TC only, which was deemed insufficient to remove the residual adhesives. Applying TC + Sof-Lex and TC + PoGo equally enhanced the results; therefore, they were the best polishing methods.

Comparison of Three Different Orthodontic Adhesives Bonded to Metallic and Ceramic Brackets: SEM and SEM/EDX Analysis (In Vitro Study).

To compare three different orthodontic adhesives (Transbond XT Light Cure Adhesive, Heliosit Orthodontic, Fuji Ortho LC) bonded to two types of orthodontic brackets: ceramic brackets (Fascination Roth 0.22) and metallic brackets (Topic Roth 0.22, Dentaurum). The study was performed on 18 human teeth (6 for each adhesive). The prepared teeth were divided into three groups according to the examination time. Subsequently, they were observed after 1, 2 and 3 weeks following bonding. After the experimental procedure, the teeth samples were cut in half along the longitudinal axis in the vestibulo-oral direction, fixed with conductive carbon cement, placed in a high-vacuum evaporator and then coated with carbon. One half of each sample was observed under a Field-emission gun scanning electron microscope (FEG-SEM Hitachi SU 8030, Japan), while on the second half of the samples qualitative (X-ray line-scans) and semi-quantitative point X-ray energy dispersive analyses (EDX) were performed with Thermo Noran (USA) NSS System 7, equipped with Ultra Dry detector (30 mm2 window). Transbond XT had an ideal bond with the enamel and the bracket base, with rare presence of microgaps and cracks in the enamel. Heliosit Orthodontic demonstrated a better bond relationship with the bracket base than the enamel, whereas in the latter the presence of microgaps in the bond was observed. The microphotographs of Fuji Ortho LC demonstrated many cracks inside the adhesive, and some of them continued to move forward into the enamel surface. Therefore, an impression of a very solid bond relationship with the enamel exists, with cracks being present in the enamel surface and never at the enamel-adhesive interface. Microgaps also appeared at the bracket-adhesive interface. Transbond XT is a highly filled composite resin and is an ideal orthodontic adhesive in each aspect examined, with an ideal enamel-adhesive and bracket-adhesive interface. Heliosit Orthodontic provides better bracket-adhesive interface compared to the enamel. Fuji Ortho LC as a solid resin-modified GIC provides a better enamel-adhesive interface, compared to the bracket base.