Editorial Type:
Article Category: Research Article
 | 
Online Publication Date: 11 Mar 2019

Biomechanical evaluation between orthodontic attachment and three different materials after various surface treatments: A three-dimensional optical profilometry analysis

,
,
, and
Page Range: 742 – 750
DOI: 10.2319/072918-547.1
Save
Download PDF

ABSTRACT

Objectives:

To determine the best bonding method of orthodontic attachment among monolithic zirconia, feldspathic porcelain, hybrid porcelain, and the impact of surface-conditioning methods using a three-dimensional optical profilometer after debonding.

Materials and Methods:

56 feldspathic porcelain, 56 monolithic zirconia, and 56 hybrid porcelain samples were divided into four surface treatment subgroups: (1) hydrofluoric (HF) acid etch + silane, (2) Al2O3 sandblasting + silane, (3) silicoating (SiO2), and (4) diamond bur + silane. The specimens were tested to evaluate shear bond strength (SBS). Residual composite was removed after debonding. Three-dimensional white-light interferometry was used to obtain quantitative measurements on surface roughness.

Results:

The highest SBS value was found for the HF acid–etched feldspathic porcelain group. The average surface roughness values were significantly higher in all material groups in which diamond bur was applied, while roughening with Cojet provided average surface roughness values closer to the original material surface.

Conclusions:

Variations in structures of the materials and roughening techniques affected the SBS and surface roughness findings.

Keywords: Three-dimensional optical profilometry; Surface roughness; Shear bond strength

INTRODUCTION

The procedure of attachment bonding may be more complicated in adult orthodontic patients because of the high incidence of dental restorations in this group. These restorations may be feldspathic porcelain, hybrid porcelain, or zirconium-based ceramic restorations, which have been increasingly preferred for esthetic and durability benefits. To date, several studies have addressed different surface-conditioning methods for orthodontic bonding to porcelain.1–4 A recently introduced air abrasion technique, based on tribochemical silica coating, provides not only mechanical retention by sandblasting but also chemicophysical bonding between the composite resin and the restoration through the use of a silane coupling agent. Restoration surfaces are blasted with 30 μm CoJet Sand (ESPE, Seefeld, Germany) with an intraoral sandblaster. However, there are insufficient data on the success of the bonding of orthodontic attachments to monolithic zirconia and hybrid ceramic materials, as they are relatively newer materials in dental practice.5–8

The aims of this study were therefore to evaluate the shear bond strength (SBS) of orthodontic attachments bonded to feldspathic porcelain, monolithic zirconia, and hybrid porcelain after various surface-conditioning methods and to evaluate the surface properties after debonding and polishing.

The null hypotheses tested in this study were the following:

  1. The SBS of orthodontic attachments is not affected by the type of material.

  2. The SBS of orthodontic attachments is not affected by the surface-conditioning method.

  3. Surface roughness after debonding is not affected by the type of the material.

  4. Surface roughness after debonding is not affected by the surface-conditioning method.

MATERIALS AND METHODS

This project was approved by the Research Ethics Committee of Baskent University School of Dentistry (protocol DK-2015/05). A power analysis was conducted to determine the sample size needed using a significance level of .05 and a power of 0.80. The resulting sample size was 50 specimens per group.

Specimen Preparation

The materials used in this study were feldspathic ceramic (Vita Block), hybrid ceramic (Vita Enamic), and monolithic zirconia (Vita YZTP), all of which were supplied as Vita brand (Zahnfabrik, Bad Säckingen, Germany). Blocks were cut to a size of 6 × 7 × 2 mm with a Micracut 201 device (Metkon, Bursa, Turkey) so that each group had 56 specimens. Ceramic blocks were obtained from the manufacturer preglazed, whereas zirconia samples were subjected to sintering for 30 minutes at 1450°C. The monolithic zirconia specimens were cut to be approximately 25% greater than the size of the sintered specimens to compensate for sintering shrinkage. All specimens were embedded in cold-curing acrylic blocks, ensuring that the glazed and polished surfaces were exposed.

Surface-Conditioning Methods

The pretreatment methods used on the restoration surfaces were as follows:

  • Group 1 (hydrofluoric [HF] acid + silane): 9.6% HF acid (Pulpdent, Watertown, Mass) was applied to the material surface for 2 minutes. After removing excess acid, the samples were washed with pressurized water for 15 seconds and dried with air for 20 seconds. Silane (ESPE-Sil, 3M ESPE, Seefeld, Germany) was applied as a single layer with a brush and left to dry.9–15

  • Group 2 (sandblasting with Al2O3 + silane): The specimen surfaces were subjected to sandblasting with 50 μm Al2O3 powder (Pureblast White No. 100-3954, Henry Schein, Melville, NY) with an intraoral air-abrasion device (Microetcher II, Danville Materials, Oakland, Calif), applied perpendicular to the sample surfaces from a distance of 10 mm for 10 seconds in circling motions at 2.5 bar pressure. Silane was applied after the removal of debris from the surfaces.9–13

  • Group 3 (silica coating with Cojet + silane): The surfaces were subjected to sandblasting with 30 μm SiO2 sand (Cojet-Sand, 3M ESPE) with an intraoral sandblasting device (Microetcher II, Danville Materials) under 2.5 bar pressure, at a 10-mm distance for 10 seconds.16

  • Group 4 (roughening with diamond bur + silane): The surfaces were roughened with ultrafine cylindrical diamond burs at 40,000 rpm for 10 seconds, and silane was applied.17

Bonding Procedure

A total of 168 metal buttons (3M Unitek, Monrovia, Calif; flat-based lingual button, model 480-100) were bonded to each conditioned material surface using a light-curing orthodontic bonding system (Transbond XT, 3M Unitek). Excess cement was removed from the button margin with a probe and light cured from the mesial and distal sides using a light-emitting diode light source (Elipar S10, 3M/Unitek) for 15 seconds.

Thermal Cycling Procedure

All specimens were subjected to thermal cycling of 1000 cycles with a 15-second waiting period and 10-second transfer period between 5 and 55°C (±5°C) in a thermal cycling device (Nuve Sanayi Malzemeleri, Ankara, Turkey).

SBS Test

The bonding resistance of buttons was assessed with a universal testing machine (LRX, Lloyd Instruments, Fareham, UK) at a cross-speed of 1 mm/min. The loading end was fixed to ensure that the shear force was parallel to the material-button interface of the specimen. The maximum force required to shear the button was recorded in Newtons and converted into megapascal (MPa = N/mm2 × 0.980665).

Surface Roughness Evaluation

Following the SBS test, any visible residual resin on specimens for each of the monolithic zirconia, hybrid ceramic, and feldspathic ceramic groups was removed using a Stainbuster bur (Abrasive Technology Ltd, London, UK) cooled with water. After removal, the surfaces of the restorative materials were consecutively polished by three different grainy porcelain polishing kits (Eve Diapol Universal Diamond Polishing Kit, EVE-RA305, Keltern, Germany). The purpose of this procedure was to examine how the material surface restored its originality when cleaned and polished after debonding. Thirteen specimens from each group were tested in an optical profilometer for surface evaluation.

Surface roughness was assessed using a three-dimensional (3D) optical profilometer (New View 7200, Zygo Corporation, Chicago, Ill). This device is a screening white-light interferometer composing a 3D surface image using the frequency domain analysis) method.

This 3D optical profilometer system featured rapid and contact-free screening. While the depth analysis was at a subnanometer level (0.1 nm), the lateral analysis was high (>0.5 μm). Measurements were taken from three points on the long axis of the examined surface (long axis of the material and 500 lm bilateral). Average roughness (Ra), total roughness (PV), kurtosis (Rku), and skewness (Rsk) values were measured with a separate formula for each unit (Figure 1):

  1. Ra (average roughness): The arithmetical mean deviation of all points from a plane fit to the test part surface.

  2. PV (total roughness): The absolute value between the highest and lowest peaks on the sample.

  3. Rku (kurtosis): The measure of the randomness of heights and of the “sharpness” of a surface.

  4. Rsk (skewness): The measure of symmetry of the profile about the mean line. Negative skew indicated a predominance of valleys, whereas positive skew indicated a “peaky” surface.

Figure 1. . Equations used by image analysis software for calculation of the selected surface roughness parameters.Figure 1. . Equations used by image analysis software for calculation of the selected surface roughness parameters.Figure 1. . Equations used by image analysis software for calculation of the selected surface roughness parameters.
Figure 1 Equations used by image analysis software for calculation of the selected surface roughness parameters.

Citation: The Angle Orthodontist 89, 5; 10.2319/072918-547.1

Statistical Analysis

Data were analyzed using IBM SPSS 17.0 (IBM Corporation, Armonk, NY) software. The normality of distribution was assessed with the Kolmogorov-Smirnov test, and homogeneity of variance was assessed with the Levene test.

The significance of the difference among the groups in terms of nonnormally distributed continuous numeric variables was assessed using the Mann-Whitney U and Kruskal-Wallis tests when the number of independent groups were two and more than two, respectively. When the Kruskal-Wallis test showed a significant result, Conover's multiple comparison test was used. Correlation analysis between continuous variables was applied using Spearman's correlation. Unless otherwise stated, an overall 5% type I error level was used to infer statistical significance. Bonferroni correction was performed to adjust for multiple comparisons in terms of testing of significance of type I error.

RESULTS

Shear Bond Strength

The SBS values of the materials and surface-conditioning methods are presented in Table 1. Of the materials conditioned with HF acid, the feldspathic porcelain group had the significantly highest bonding resistance (8.84). The surface-conditioning method did affect the SBS on different surfaces.

Table 1 Shear Bond Strength Comparison of Tooth Group, Materials, and Surface-Conditioning Methods*
Table 1

Surface Roughness

The Ra, PV, Rsk, and Rku values of the surface-conditioning subgroups are presented in Table 2 as mean (min-max) values. Within the porcelain group, the HF acid and Cojet surface-conditioning methods resulted in significantly lower average roughness (Ra) values (0.39, 0.28) compared with roughening with Al2O3 and diamond bur (0.89, 0.92). Likewise, the Ra values were significantly higher with Al2O3 and diamond bur applications (0.75, 0.81) compared with HF acid and Cojet (0.39, 0.47) on the hybrid ceramic surface. On the other hand, the diamond bur caused significantly higher Ra values when compared with the other surface-conditioning methods on the monolithic zirconia surface (0.81 > 0.51 > 0.31 > 0.28).

Table 2 Surface Roughness Comparison of Materials and Surface-Conditioning Methods*
Table 2

Comparisons between raw materials and processed materials are presented in Table 3. The 3D oblique surface plots (interferograms) and vertical surface plots of each test group are presented in Figures 2–5.

Table 3 Surface Roughness Comparison of Unprocessed Materials and Material Subgroupsa
Table 3
Figure 2. . Three-dimensional oblique surface plots (interferograms) of a representative specimen from the Enamic group conditioned with (a) Al2O3, (b) diamond bur, (c) Cojet, (d) HF acid. In each figure, the solid plot (left upper corner) depicts the surface texture when viewed perpendicularly.Figure 2. . Three-dimensional oblique surface plots (interferograms) of a representative specimen from the Enamic group conditioned with (a) Al2O3, (b) diamond bur, (c) Cojet, (d) HF acid. In each figure, the solid plot (left upper corner) depicts the surface texture when viewed perpendicularly.Figure 2. . Three-dimensional oblique surface plots (interferograms) of a representative specimen from the Enamic group conditioned with (a) Al2O3, (b) diamond bur, (c) Cojet, (d) HF acid. In each figure, the solid plot (left upper corner) depicts the surface texture when viewed perpendicularly.
Figure 2 Three-dimensional oblique surface plots (interferograms) of a representative specimen from the Enamic group conditioned with (a) Al2O3, (b) diamond bur, (c) Cojet, (d) HF acid. In each figure, the solid plot (left upper corner) depicts the surface texture when viewed perpendicularly.

Citation: The Angle Orthodontist 89, 5; 10.2319/072918-547.1

Figure 3. . Three-dimensional oblique surface plots (interferograms) of a representative specimen from the feldspathic porcelain group conditioned with (a) Al2O3, (b) diamond bur, (c) Cojet, (d) HF acid. In each figure, the solid plot (left upper corner) depicts the surface texture when viewed perpendicularly.Figure 3. . Three-dimensional oblique surface plots (interferograms) of a representative specimen from the feldspathic porcelain group conditioned with (a) Al2O3, (b) diamond bur, (c) Cojet, (d) HF acid. In each figure, the solid plot (left upper corner) depicts the surface texture when viewed perpendicularly.Figure 3. . Three-dimensional oblique surface plots (interferograms) of a representative specimen from the feldspathic porcelain group conditioned with (a) Al2O3, (b) diamond bur, (c) Cojet, (d) HF acid. In each figure, the solid plot (left upper corner) depicts the surface texture when viewed perpendicularly.
Figure 3 Three-dimensional oblique surface plots (interferograms) of a representative specimen from the feldspathic porcelain group conditioned with (a) Al2O3, (b) diamond bur, (c) Cojet, (d) HF acid. In each figure, the solid plot (left upper corner) depicts the surface texture when viewed perpendicularly.

Citation: The Angle Orthodontist 89, 5; 10.2319/072918-547.1

Figure 4. . Three-dimensional oblique surface plots (interferograms) of a representative specimen from the monolithic-zirconia group conditioned with (a) Al2O3, (b) diamond bur, (c) Cojet, (d) HF acid. In each figure, the solid plot (left upper corner) depicts the surface texture when viewed perpendicularly.Figure 4. . Three-dimensional oblique surface plots (interferograms) of a representative specimen from the monolithic-zirconia group conditioned with (a) Al2O3, (b) diamond bur, (c) Cojet, (d) HF acid. In each figure, the solid plot (left upper corner) depicts the surface texture when viewed perpendicularly.Figure 4. . Three-dimensional oblique surface plots (interferograms) of a representative specimen from the monolithic-zirconia group conditioned with (a) Al2O3, (b) diamond bur, (c) Cojet, (d) HF acid. In each figure, the solid plot (left upper corner) depicts the surface texture when viewed perpendicularly.
Figure 4 Three-dimensional oblique surface plots (interferograms) of a representative specimen from the monolithic-zirconia group conditioned with (a) Al2O3, (b) diamond bur, (c) Cojet, (d) HF acid. In each figure, the solid plot (left upper corner) depicts the surface texture when viewed perpendicularly.

Citation: The Angle Orthodontist 89, 5; 10.2319/072918-547.1

Figure 5. . Three-dimensional oblique surface plots (interferograms) of a representative specimen of unprocessed raw material surface: (a) Enamic, (b) feldspathic porcelain, (c) monolithic zirconia. In each figure, the solid plot (left upper corner) depicts the surface texture when viewed perpendicularly.Figure 5. . Three-dimensional oblique surface plots (interferograms) of a representative specimen of unprocessed raw material surface: (a) Enamic, (b) feldspathic porcelain, (c) monolithic zirconia. In each figure, the solid plot (left upper corner) depicts the surface texture when viewed perpendicularly.Figure 5. . Three-dimensional oblique surface plots (interferograms) of a representative specimen of unprocessed raw material surface: (a) Enamic, (b) feldspathic porcelain, (c) monolithic zirconia. In each figure, the solid plot (left upper corner) depicts the surface texture when viewed perpendicularly.
Figure 5 Three-dimensional oblique surface plots (interferograms) of a representative specimen of unprocessed raw material surface: (a) Enamic, (b) feldspathic porcelain, (c) monolithic zirconia. In each figure, the solid plot (left upper corner) depicts the surface texture when viewed perpendicularly.

Citation: The Angle Orthodontist 89, 5; 10.2319/072918-547.1

DISCUSSION

Orthodontists are often obliged to bond orthodontic attachments to various dental restorations. Feldspathic is a silica-based porcelain, while zirconia is non–silica-based ceramic. Hybrid ceramic is another recently developed material that combines ceramic and composite. This study aimed to assess the bonding resistance of orthodontic attachments to porcelain, hybrid ceramic, and monolithic zirconia surfaces by different surface-roughening techniques and to determine the most appropriate method. The HF acid + porcelain combination yielded the highest SBS, while Al2O3 sandblasting + zirconia had the lowest. Roughening the surface with HF acid modifies the material surface by partial dissolution of the glassy matrix, which contains silica and results in 5–7 μm of micro porosity and a strong micromechanical connection.14,15 Silane is capable of forming a siloxane network with the silica in the ceramic surface, which leads to wetting and penetration of resin into those micro porosities. This could explain why the HF acid + silane and porcelain combination yielded a better SBS value. This chemical interaction is not applicable to zirconia, which lacks a silica phase.18–22 In previous studies, applying a diamond bur to a zirconia surface did not affect the SBS.18,19 However, sandblasting with either Al2O3 or Cojet is known to increase the surface area, creating microcracks and mechanical retention. Some studies have claimed that mechanical abrasion techniques cause a phase change on a zirconia surface.23 Other studies have reported that chemical agents are more effective than mechanical conditioning in terms of bonding resistance to a zirconia surface. In contrast to the literature, the results of this study showed that the highest SBS value was found for HF acid roughening on monolithic zirconia.24 In addition, the results of Cojet were found to be better than Al2O3 sandblasting, which might be due to silica-coated particles. Silica particles also have a chemical effect besides roughening the surface. The relatively lower SBS values of Al2O3 sandblasting might have been affected by the duration of sandblasting, the particle size of the sand, and differences in application techniques.

Regarding the biocompatibility of the surface-conditioning methods tested, HF acid acts as a metabolic toxin. When HF acid contacts the skin or mucosa, deep tissue necrosis occurs within 24 to 48 hours. Sandblasting with Al2O3 or Cojet can be considered as safe when compared with HF acid. This factor should also be taken into consideration when deciding on the surface-conditioning technique.

Another aim of the study was the evaluation of the surface characteristics of restoration and tooth surfaces with a noncontact optical profilometer. The roughest surface was obtained with the diamond bur in all groups. Representative interferograms are clearly indicative of the scratches over the material surfaces in a wavy pattern, when a diamond bur was used. Based on these findings, diamond bur, which applies a shearing force onto the surface, cannot be recommended for surface conditioning. The smoothest material surface was obtained with both HF acid and Cojet applications. Although a comparison of surface roughness parameters with other studies was not possible because of the lack of published data on 3D profilometry images of restoration surfaces, the findings obtained on the feldspathic porcelain surface were consistent with previous reports. Saraç et al.25 compared the influence of HF acid etching and sandblasting on the porcelain surface roughness and found significant values that were close to each other. It was reported that a diamond bur and Al2O3 sandblasting obtained the highest roughness values, and in another study, the lowest roughness values were obtained by silicoating and HF acid etching on a porcelain surface.26 The results of this study revealed that the highest Ra values for ceramic subgroups were obtained in the diamond bur and Al2O3 groups, followed by the HF acid group. It is crucial to state that conditioning the porcelain surface with Cojet resulted in almost the same surface roughness when compared with the unprocessed porcelain surface.

Sandblasting with either Al2O3 or Cojet did not cause excessive detrimental effects on the zirconia surface in this study. The Ra values of these applications were close to the original zirconia surface and can be considered safe. According to Sarmento et al.,27 air abrasion with 110 μm Al2O3 resulted in higher roughness, but air-abrasion protocols with SiO2 promoted better adhesion on a zirconia surface. The difference between Al2O3 and Cojet roughening on the monolithic zirconia surface was not significant in terms of the Ra value. However, the size of the sand particles and pressure of the devices may vary in different studies. Accordingly, the HF acid group had higher mean roughness values compared with Al2O3, which was consistent with other reports. When hybrid ceramic material is used, HF acid and Cojet techniques are more reliable methods in terms of occurrence of less degeneration in surface characteristics when compared with the unprocessed Enamic.

None of the applications were able to return the surface structures to their original condition. Nevertheless, comparisons between subgroups showed that surface characteristics that were most similar to their natural condition were obtained after roughening with Cojet or HF acid. Furthermore, it may be suggested that if intraoral sandblasting is to be performed for roughening, SiO2 may be preferred over Al2O3. Surface-roughening methods analyzed in this study elicited different surface roughness findings, which in turn rejected the third and fourth hypotheses of the study.

When appropriate roughening and cleaning techniques are followed, an acceptable surface structure and bonding success can be obtained throughout treatment in patients with dental restorations. When both SBS and surface roughness characteristics of conditioning methods were taken into consideration, HF acid etching seemed to be the best technique based on the results obtained within the limitations of this study. However, clinicians should be aware of the possible hazardous effects of HF acid when used improperly.

CONCLUSIONS

  • Variations of surface types of the materials affected the bonding resistance of orthodontic attachments. Comparisons of the materials with each other showed the highest bonding resistance to be for the feldspathic porcelain + HF acid group.

  • Surface-roughening techniques affected the bonding resistance of the materials. In particular, material groups in which HF acid was applied had higher bonding resistance compared with the other subgroups. This conclusion should be interpreted with caution when the biosafety of the materials is considered.

  • Variations in structures of the materials and roughening techniques affected the surface roughness findings. Examination of the surface roughness of all the unprocessed materials showed that none of the materials were able to return to their initial surface roughness values after debonding and polishing. The Ra values were significantly higher in all material groups in which a diamond bur was applied, while roughening with Cojet provided Ra values closer to the original material surface.

  • All of the null hypotheses tested in this study were rejected.

REFERENCES

  • 1

    Smith GGA,
    McInnes-Ledoux P,
    Ledoux WR,
    Weinberg R.
    Orthodontic bonding to porcelain-bond strength and refinishing. Am J Orthod Dentofac Orthop. 1988;94:245–252.

  • 2

    Bourke BM,
    Rock WP.
    Factors affecting the shear bond strength of orthodontic brackets to porcelain. Br J Orthod. 1999;26:285–290.

  • 3

    Schmage P,
    Nergiz I,
    Herrmann W,
    Ozcan M.
    Influence of various surface-conditioning methods on the bond strength of metal brackets to ceramic surfaces. Am J Orthod Dentofac Orthop. 2003;123:540–546.

  • 4

    Ozcan M.
    The use of chairside silica coating for different dental applications: a clinical report. J Prosthet Dent. 2002;87:469–472.

  • 5

    Sari F,
    Secilmis A,
    Simsek I,
    Ozsevik S.
    Shear bond strength of indirect composite material to monolithic zirconia. J Adv Prosthodont. 2016;8:267–274.

  • 6

    Bavbek NC,
    Roulet JF,
    Ozcan M.
    Evaluation of microshear bond strength of orthodontic resin cement to monolithic zirconium oxide as a function of surface conditioning method. J Adhes Dent. 2014;16:473–480.

  • 7

    Ozcan M,
    Bernasconi M.
    Adhesion to zirconia used for dental restorations: a systematic review and meta-analysis. J Adhes Dent. 2015;17:7–26.

  • 8

    Buyuk SK,
    Kucukekenci AS.
    Effects of different etching methods and bonding procedures on shear bond strength of orthodontic metal brackets applied to different CAD/CAM ceramic materials. Angle Orthod. 2018;88:221–226.

  • 9

    Schmage P,
    Nergiz I,
    Herrmann W,
    Özcan M.
    Influence of various surface-conditioning methods on the bond strength of metal brackets to ceramic surfaces. Am J Orthod Dentofac Orthop. 2003;123:540–546.

  • 10

    Girish PV,
    Dinesh U,
    Bhat CS,
    Shetty PC.
    Comparison of shear bond strength of metal brackets bonded to porcelain surface using different surface conditioning methods: an in vitro study. J Contemp Dent Pract. 2012;13:487–493.

  • 11

    Sarac YS,
    Kulunk T,
    Elekdag-Turk S,
    Turk T.
    Effects of surface conditioning methods on shear bond strength of orthodontic brackets bonded to different all-ceramic materials. Eur J Orthod. 2011;33:667–672.

  • 12

    Hosseini MH,
    Sobouti F,
    Etemadi A,
    Chiniforush N,
    Shariati M.
    Shear bond strength of metal brackets to feldspathic porcelaintreated by Nd:YAG laser and hydrofloric acid. Lasers Med Sci. 2015;30:837–41.

  • 13

    Zarif Najafi H, Oshagh M, Torkan S, Yousefipour B, Salehi R. Evaluation of the effect of four surface conditioning methods on the shear bond strength of metal bracket to porcelain surface. Photomed Laser Surg. 2014;32:694–699.

  • 14

    Zachrisson YØ,
    Zachrisson BU,
    Büyükyilmaz T.
    Surface preparation for orthodontic bonding to porcelain. Am J Orthod Dentofac Orthop. 1996;109:420–430.

  • 15

    Blatz MB,
    Sadan A,
    Kern M.
    Resin-ceramic bonding: a review of the literature. J Prosthet Dent. 2003;89:268–274.

  • 16

    Eslamian L,
    Borzabadi-Farahani A,
    Mousavi N,
    Ghasemi A.
    A comparative study of shear bond strength between metal and ceramic brackets and artificially aged composite restorations using different surface treatments. Eur J Orthod. 2012;34:610–617.

  • 17

    Bayram M,
    Yesilyurt C,
    Kusgöz A,
    Ulker M,
    Nur M.
    Shear bond strength of orthodontic brackets to aged resin composite surfaces: effect of surface conditioning. Eur J Orthod. 2011;33:174–179.

  • 18

    Manicone PF,
    Iommetti PR,
    Raffaelli L.
    An overview of zirconia ceramics: basic properties and clinical applications. J Dent. 2007;35:819–826.

  • 19

    Beuer F,
    Stimmelmayr M,
    Gueth J-F,
    Edelhoff D,
    Naumann M.
    In vitro performance of full-contour zirconia single crowns. Dent Mater. 2012;28:449–456.

  • 20

    Denry I,
    Kelly JR.
    State of the art of zirconia for dental applications. Dent Mater. 2008;24:299–307.

  • 21

    Al-Amleh B,
    Lyons K,
    Swain M.
    Clinical trials in zirconia: a systematic review. J Oral Rehabil. 2010;37:641–652.

  • 22

    Kontos L,
    Schille C,
    Schweizer E,
    Geis-Gerstorfer J.
    Influence of surface treatment on the wear of solid zirconia. Acta Odontol Scand. 2013;71:482–487.

  • 23

    Guazzato M,
    Quach L,
    Albakry M,
    Swain MV.
    Influence of surface and heat treatments on the flexural strength of y-tzp dental ceramic. J Dent. 2005;33:9–18.

  • 24

    Amaral R,
    Ozcan M,
    Bottino MA,
    Valandro LF.
    Microtensile bond strength of a resin cement to glass infiltrated zirconia-reinforced ceramic: the effect of surface conditioning. Dent Mater. 2006;22:283–290.

  • 25

    Saraç YS,
    Elekdag-Turk S,
    Saraç D,
    Turk T.
    Surface conditioning methods and polishing techniques effect on surface roughness of a feldspar ceramic. Angle Orthod. 2007;77:723–728.

  • 26

    Schmage P,
    Nergiz I,
    Herrmann W,
    Özcan M.
    Influence of various surface-conditioning methods on the bond strength of metal brackets to ceramic surfaces. Am J Orthod Dentofac Orthop. 2003;123:540–546.

  • 27

    Sarmento HR,
    Campos F,
    Sousa RS,
    Machado JPB,
    Souza ROA,
    Bottino MA.
    Influence of air-particle deposition protocols on the surface topography and adhesion of resin cement to zirconia. Acta Odontol Scand. 2014;72:346–353.

Copyright: © 2019 by The EH Angle Education and Research Foundation, Inc.
<bold>Figure 1</bold>
Figure 1

Equations used by image analysis software for calculation of the selected surface roughness parameters.

<bold>Figure 2</bold>
Figure 2

Three-dimensional oblique surface plots (interferograms) of a representative specimen from the Enamic group conditioned with (a) Al2O3, (b) diamond bur, (c) Cojet, (d) HF acid. In each figure, the solid plot (left upper corner) depicts the surface texture when viewed perpendicularly.

<bold>Figure 3</bold>
Figure 3

Three-dimensional oblique surface plots (interferograms) of a representative specimen from the feldspathic porcelain group conditioned with (a) Al2O3, (b) diamond bur, (c) Cojet, (d) HF acid. In each figure, the solid plot (left upper corner) depicts the surface texture when viewed perpendicularly.

<bold>Figure 4</bold>
Figure 4

Three-dimensional oblique surface plots (interferograms) of a representative specimen from the monolithic-zirconia group conditioned with (a) Al2O3, (b) diamond bur, (c) Cojet, (d) HF acid. In each figure, the solid plot (left upper corner) depicts the surface texture when viewed perpendicularly.

<bold>Figure 5</bold>
Figure 5

Three-dimensional oblique surface plots (interferograms) of a representative specimen of unprocessed raw material surface: (a) Enamic, (b) feldspathic porcelain, (c) monolithic zirconia. In each figure, the solid plot (left upper corner) depicts the surface texture when viewed perpendicularly.

Contributor Notes

Corresponding author: Dr Çağla Şar, Istanbul Okan Üniversitesi, Diş Hekimliği Fakültesi, Ortodonti Anabilim Dalı, Mecidiyeköy-İstanbul, Turkey (e-mail: caglasar@yahoo.com)
Received: 01 Jul 2018
Accepted: 01 Jan 2019
  • Download PDF