Clinical evaluation of two in-office dental bleaching agents.

PURPOSE: To evaluate the bleaching efficacy and time required for color stability immediately after dental office bleaching. METHODS: 40 subjects were randomly divided into two groups, according to the bleaching agent used:GHP - 35% hydrogen peroxide gel and GCP - 37% carbamide peroxide gel. The color was measured with a spectrophotometer before and immediately, 24 hours, 72 hours, 7 days and 15 days after the bleaching procedure. The color parameters were evaluated and the ΔE*, ΔL*, Δa* and Δb* values were calculated for each evaluation period. The data was statistically analyzed with Student's T-test, one-way ANOVA and Tukey's post hoc test (P ≤ 0.05). RESULTS: Regarding the ΔE* values, in the assessed periods there were no significant differences between groups (P≥ 0.05). However, the luminosity (ΔL*) decreased considerably in both groups in the first 72 hours (P≤ 0.05), followed by an increase at 15 days (P≤ 0.05) in the hydrogen peroxide group. Regarding the Δb* values, the GHP showed higher negative alterations in the b* axis in the first 24 hours. The 37% carbamide peroxide gel and the 35% hydrogen peroxide gel were effective and there was no reversal of tooth color within 15 days; however a more accentuated bleaching effect was observed immediately after bleaching. CLINICAL SIGNIFICANCE: Rapid bleaching was observed immediately after the in-office bleaching treatment.

CAD/CAM ceramic fragments in anterior teeth: A clinical report.

OBJECTIVE: The treatment of fractured teeth has become a great opportunity to investigate new approaches in the field of restorative dentistry. Restoring teeth with ceramic fragments is a great challenge, however, the computer aided design/computer aided manufacturing (CAD/CAM) technology allows the fabrication of both laminate veneers and ceramic fragments. MATERIALS AND METHODS: Thus, the aim of this article was to report a clinical case where anterior teeth, fractured due to a sport practice, were restored with CAD/CAM ceramic fragments. CONCLUSIONS: It was observed that with this kind of restoration optimum esthetic results might be achieved when treating anterior fractured teeth. CLINICAL SIGNIFICANCE: Ceramic fragments using CAD/CAM systems are a viable clinical alternative to composites for the reconstruction of fractured teeth. Function and esthetics can be restored with the use of this treatment quickly and efficiently.

Color stability of shade guides after autoclave sterilization.

This study evaluated the influence of 120 autoclave sterilization cycles on the color stability of two commercial shade guides (Vita Classical and Vita System 3D-Master). The specimens were evaluated by spectrophotometer before and after the sterilization cycles. The color was described using the three-dimensional CIELab system. The statistical analysis was performed in three chromaticity coordinates, before and after sterilization cycles, using the paired samples t test. All specimens became darker after autoclave sterilization cycles. However, specimens of Vita Classical became redder, while those of the Vita System 3D-Master became more yellow. Repeated cycles of autoclave sterilization caused statistically significant changes in the color coordinates of the two shade guides. However, these differences are considered clinically acceptable.

Stress amplifications in dental non-carious cervical lesions.

This study aims to investigate the influence of the presence, shape and depth of NCCLs on the mechanical response of a maxillary second premolar subjected to functional and non-functional occlusal loadings using 3-D finite element (FE) analysis. A three-dimensional model of a maxillary second premolar and its supporting bone was constructed based on the contours of their cross-sections. From the sound model, cervical defects having either V- or U-shapes, as found clinically, were subtracted in three different depths. The models were loaded with 105 N to simulate normal chewing forces according to a functional occlusal loading (F1) vertically applied and two non-functional loadings (F2 and F3) obliquely oriented. Two alveolar bone crest heights were tested. Ansys™ FE software was used to compute stress distributions and maximum principal stress for each of the models. The presence of a lesion had no effect on the overall stress distribution of the system, but affected local stress concentrations. Non-functional loadings exhibited tensile stresses concentrating at the cervical areas and root surfaces, while the functional loading resulted in homogeneous stress distributions within the tooth. V-shaped lesions showed higher stress levels concentrated at the zenith of the lesion, whereas in U-shaped defect stresses concentrated over a wider area. As the lesions advanced in depth, the stress was amplified at their deepest part. A trend of stress amplification was observed with decreasing bone height. These results suggest a non-linear lesion progression with time, with the progression rate increasing with patient's age (deeper lesions and lower bone support).

Should acid etching be performed prior to nonvital bleaching?

This study sought to measure the microtensile bond strength of a nanofilled composite resin to human dentin after phosphoric acid etching followed by nonvital bleaching. Scanning electron microscopy was used to analyze fracture modes. Twenty extracted sound human maxillary premolars were prepared for Class I defects and assigned randomly to 4 groups (n = 5): Group 1 (control group) samples were unbleached and had no previous acid etching; Group 2 samples were bleached only, Group 3 samples were acid-etched for 15 seconds prior to bleaching, and Group 4 samples were acid-etched for 30 seconds prior to bleaching. There were no statistically significant differences of bond strength values among Groups 1-3; however, the mean values of Group 4 were statistically lower compared with the other groups.

Effect of multiple coats of ultra-mild all-in-one adhesives on bond strength to dentin covered with two different smear layer thicknesses.

PURPOSE: To evaluate the effect on bond strength of 1, 2, or 3 coats of two one-step self-etching adhesives on dentin covered with two different smear layer thicknesses. MATERIALS AND METHODS: Flat dentin surfaces from recently extracted third molars were wet ground with 60- or 600-grit SiC paper to produce smear layers of different thicknesses. Adper Easy Bond (3M ESPE) and Clearfil S3 Bond (Kuraray) were applied in 1, 2, or 3 consecutive coats after air drying each coat. ScotchBond Multi Purpose (3M) and Clearfil SE Bond (Kuraray) were used as controls. Composite resin crowns (Filtek Z250, 3M ESPE) were built up, stored for 24 h, and cut in x and y directions. Eight to twelve sticks (0.65 ± 0.05 mm2 of area) from the central area of each tooth were fractured in tension (0.5 mm/min). Sticks from each group were processed for interfacial micromorphological evaluation with SEM. RESULTS: Three-way ANOVA revealed a significant interaction between factors (p < 0.05). Tukey's post-hoc test showed that only when Adper Easy Bond was applied on dentin prepared with 600-grit SiC paper, microtensile bond strength was not significantly affected by the number of coatings. However, the effect of smear layer thickness was only statistically significant when the adhesives were applied in one coat, for both adhesives. When they were applied in two or three coats, smear layer thickness did not significantly affect bond strength (p > 0.05). CONCLUSIONS: The thickness of the smear layer affected the bond strength of both all-in-one adhesives. Additional coats can be beneficial to bond strength, especially with Clearfil S3 Bond.

The influence of different placement techniques on the microtensile bond strength of low-shrink silorane composite bonded to Class I cavities.

The aim of this in vitro study was to evaluate the microtensile bond strength (µTBS) of a low-shrink silorane-based composite (Filtek Silorane) and a methacrylate-based composite (Filtek Z250) to the bottom dentin of a Class I cavity using different placement techniques. Twelve third molars were used. Standard, box-type Class I cavities (6.0 x 4.0 x 2.5 mm) were prepared at the occlusal crown center, with the pulpal floor ending approximately at the midcoronal dentin. The teeth were then randomly divided into four groups, according to each placement technique: ZI--Filtek Z250 placed incrementally; ZB--Filtek Z250 placed in bulk; SI--Filtek Silorane placed incrementally; and SB--Filtek Silorane placed in bulk. Each restored third molar was subjected to microtensile bond testing after 24 hours of storage in distilled water at 37 degrees C. After storage, each molar was longitudinally sectioned in both axes to obtain rectangular sticks with an approximate 0.49 mm2 cross-sectional area. Data were analyzed by one-way ANOVA followed by a Tukey post hoc test (P = 0.05). After debonding, the failure modes were analyzed using a stereomicroscope. The ZI group (72.6 MPa) showed the highest µTBS, followed by the ZB group (60.2 MPa), while the SI (34.4 MPa) and SB (42.6 MPa) groups demonstrated statistically significant lower bond strengths. The type of placement technique did not influence the µTBS of silorane-based composites to the bottom dentin of Class I cavities. The methacrylate-based composite showed superior performance, regardless of the placement technique.

Slow progression of dentin bond degradation during one-year water storage under simulated pulpal pressure.

OBJECTIVES: To evaluate the dentin bond durability of simplified adhesives after one-year (1 y) under water storage and simulated pulpal pressure. METHODS: Class I cavities were prepared in sixty human third molars with the pulpal wall located in mid-coronal dentin. The roots were cut off to expose the pulpal chamber, and the teeth were assembled in a pulpal pressure simulator device. A two-step etch-and-rinse adhesive (Single Bond 2/SB), a two-step self-etch adhesive (Clearfil SE Bond/CSE), a three-step self-etch adhesive (Adper Scotchbond SE/SSE) and three all-in-one adhesives (Adper Easy Bond/EB, Clearfil S(3) Bond/S3 and Adhese One/AO) were applied according to manufacturers instructions. No enamel pre-etching was used for the self-etch systems. The cavities were filled with a composite (Z250, 3M ESPE) in four to five horizontal increments and individually cured. Immediately after the final cure, pulpal pressure was set to 15 cm H(2)O. After 24 h and 1 y under simulate pulpal pressure the teeth were cut following a 'nontrimming' microtensile test technique (n=30) and tested in tension. Kruskall-Wallis and post hoc multiple comparisons were used at alpha=0.05. Weibull statistics was applied to SB, CSE and EB. Fractographic analysis of debonded specimens was performed using scanning electron microscopy. RESULTS: At 24 h and 1 y periods, SB showed higher bond strength means than all the others adhesives tested. CSE was not statistically different from EB at 24 h and from EB and SB at 1 y. EB showed bond strength statistically higher than the other three self-etch adhesives, which were not statistically different from each other at 24 h. AO showed significantly lower bond strength than all tested materials after 1 y. For all adhesives the mean bond strength at 1 y were not statistically different from the values measured at 24 h (p>0.05). Shifts in failure mode patterns and Weibull modulus decrease indicate some degree of bond degradation after the 1 y storage period. CONCLUSION: One-year of simulated pulpal pressure did not affect dentin bond strength of simplified adhesives in Class I restorations. Signs of degradation were only revealed by fractographic analysis and reliability parameters.

Fragment bonding of fractured anterior teeth: case report.

The unharmonious esthetic appearance of anterior teeth can be caused by changes in tooth color, shape, and size or by traumatic dental injury. Because the fragment bonding technique can restore functionality, morphology, and especially esthetics, it should be one of the choices in the restoration of fractured anterior teeth if the fragment is available. This article describes a clinical case of bonding of fractured anterior teeth and demonstrates how an esthetic appearance can be satisfactorily restored without wear to sound structure.

Optical influence of the type of illuminant, substrates and thickness of ceramic materials.

OBJECTIVES: The present study is an instrumental evaluation of the optical influence of the type of illuminant, substrate and different thickness on the color of dental ceramics. METHODS: Thirty ceramic disks were prepared from IPS-Empress and IPS-Empress2 in three different thicknesses (1.5, 2.0 and 2.5mm). Disks made of composite resin; silver-palladium alloy and gold were used as substrates. The disks with a 1.5mm thickness were placed on a neutral gray photographic paper and measured with a spectrophotometer under three illuminants: daylight (D65), incandescent light (A) and fluorescent light (F6). All ceramic disks were combined with the substrate disks and a spectrophotometer was used to measure the coordinates of lightness (L*) and chromaticity (a* and b*). Two-way ANOVA (p<0.05) was used to analyze the combinations of ceramics, substrates and illuminants tested considering the coordinates of lightness (L*) and chromaticity (a* and b*), and also differences of color (DeltaE), lightness (DeltaL*), chromaticity values (Deltaa* and Deltab*). RESULTS: For the illuminants tested, the results present significant differences for coordinates of chromaticity a* and b*, suggesting a metamerism effect. In combination with the substrates, the results present statistical differences in all the tested conditions, especially where there is no ceramic substructure. SIGNIFICANCE: The presence of discolored tooth remnants or metallic posts and cores can interfere with the desired aesthetic result, based on the selection of color aided by a single luminous source. Thus, the substrate color effect, thickness of the ceramic materials and type of illuminant are important factors to be considered during the clinical application of the ceramic systems.

The influence of two home-applied bleaching agents on enamel microhardness: an in situ study.

OBJECTIVE: This in situ study evaluated the influence of two home-applied bleaching agents (10% carbamide peroxide and 7.5% hydrogen peroxide) on enamel microhardness. METHODS: Ninety enamel slabs were obtained from human third molars and baseline Knoop hardness measurements were recorded under a 50 g load for 5s. The specimens were attached to intra-oral devices delivered to 10 volunteers (donor of the teeth) who used the devices 24h/day throughout the experiment. The specimens were divided in three groups, two experimental and one control; in the last group, enamel slabs were not submitted to bleaching agents, but exposed only to the action of saliva. Two custom-made trays were made for each volunteer to recover the teeth and the appliances containing the enamel slabs. The bleaching regimen was 1h/day for 21 consecutive days. Subsequently, additional hardness measurements were recorded. RESULTS: The mean values of the baseline and final microhardness were: 348 and 352.2; 346.6 and 354.5; 342 and 340.8, for control, 10% carbamide peroxide and 7.5% hydrogen peroxide groups, respectively. One-way ANOVA of the microhardness mean values revealed no statistically significant differences among groups, the specimens treated with 7.5% hydrogen peroxide has shown a tendency (p=0.056) to microhardness decrease. CONCLUSIONS: Data suggested that the tested home bleaching agents did not change the superficial enamel microhardness.

A new proposal to optimize the occlusal margin in direct resin composite restorations of posterior teeth.

Modern operative dentistry provides practitioners of esthetic dentistry the means for performing direct restorations in a virtually imperceptible way. However, this attribute of resin composite can cause difficulties because the absence of contrast between the tooth structure and the restoration can impede visualization of the cavity limits. The purpose of this article is to highlight some operative steps that, when appropriately performed, will facilitate the building of direct resin composite restorations in posterior teeth, significantly reducing the possibility of restorative overextension.

Interfacial morphology of self-etching adhesive systems in dentin.

OBJECTIVE: To portray and assess the interfacial morphology achieved with self-etching systems in dentin under observation by scanning electron microscopy. METHOD AND MATERIALS: Ten caries-free extracted erupted human third molars were used in this study. The occlusal enamel was removed, and 10 dentin disks with a thickness of 800 +/- 200 Microm were obtained by slow-speed sectioning with a diamond saw parallel to the occlusal surface. A standard smear layer was created on the occlusal surface by wet sanding with 600-grit sandpaper for 60 seconds. The dentin disks were randomly assigned to one of the systems: AdheSE (Ivoclar Vivadent), Optibond Solo Plus-Self-Etch (Kerr), Tyrian SPE (Bisco) as self-etching primers, and Adper Prompt Self-Etch (3M Espe) and One-Up Bond F (Tokuyama) as self-etching adhesives. All systems were applied according to the manufacturers' instructions. After application of the adhesive systems, a 1.0-mm-thick layer of a flowable composite resin (Filtek Flow; 3M Espe) was applied to the treated dentin surface and light cured for 40 seconds. The specimens were then processed for observation by scanning electron microscopy. RESULTS: All self-etching systems achieved the formation of sealed interfaces and hybridized areas with variable extents except for the self-etching adhesive One-Up Bond F, which showed some gap formation and poor hybridization. Optibond Solo Plus-Self-Etch presented a more consistent adhesive interface with thicker hybrid layers, numerous resin tags, and lateral branches. CONCLUSION: Regarding the micromorphology aspect, Optibond Solo Plus-Self-Etch showed the finest result, while One-Up Bond F was not able to produce a satisfactory ultrastructural morphology.

Color in natural teeth and direct resin composite restorations: essential aspects.

This article presents the essential aspects for understanding and reproducing the color of natural teeth with the use of direct resin composite. Fluorescence and opalescence are discussed, with special emphasis on counter-opalescence, which is primarily responsible for the appearance of an orange discoloration at the mamelon dentin tips and incisal edges of anterior teeth. The dynamics of color in natural teeth in relation to age is also discussed, focusing on the age-related changes that occur in enamel, dentin, and pulp. Further, it is demonstrated how to reproduce the esthetic features of natural teeth using latest-generation direct resin composites.

Dentin bond strengths of simplified adhesives: effect of dentin depth.

The objective of this study was to compare the shear bond strength of 3 simplified adhesive systems applied on shallow vs deep dentin. For superficial dentin, 30 human molars were sectioned with a diamond saw to expose dentin immediately below the dentoenamel junction. For deep dentin, 30 molars were sectioned 3 mm below the dentoenamel junction. The teeth were mounted, polished to 600-grit, and randomly assigned to 3 groups (n=10): Single Bonda and OptiBond Solo, total-etch adhesives, and Clearfil Liner Bond 2V, a self-etching primer adhesive. Adhesives were applied, the restorative material Filtek Z250 inserted in a No. 5 gelatin capsule, and light-cured. After 24 hours in water at 37 degrees C, shear bond strength was measured with an Instron at 5 mm/min. The data were analyzed with 2-way ANOVA and Duncan's post-hoc test. The results showed the following shear bond strengths (mean +/- SD in MPa): Single Bond/superficial dentin = 22.1 +/- 2.8; Single Bond/deep dentin = 14.2 +/- 7.0; OptiBond Solo/superficial dentin = 18.9 +/- 4.1; OptiBond Solo/deep dentin = 18.4 +/- 4.8; Clearfil Liner Bond 2V/superficial dentin = 21.0 +/- 7.4; Clearfil Liner Bond 2V/deep dentin = 17.6 +/- 5.9. There were no significant differences between mean shear bond strength for the factor "adhesive system" (P>.822). The Duncan's test showed that Single Bond resulted in higher shear bond strength on superficial dentin than on deep dentin. The mean shear bond strength for Clearfil Liner Bond 2V and OptiBond Solo were not influenced by dentin depth. When data were pooled for dentin depth, deep dentin resulted in statistically lower bond strengths than superficial dentin (P<.01). The influence of dentin depth on shear bond strength depends on the specific composition of the dentin adhesive.

Esthetic noncarious Class V restorations: a case report.

UNLABELLED: When restoring anterior and posterior teeth affected by noncarious cervical lesions, many clinicians overlook the etiologic factors responsible for the lesions' development, resulting in frequent restorative failures. The treatment approach for noncarious cervical lesions must not be based only on restorative procedures since a variety of causative and aggravating factors are related to their formation. This article discusses a treatment protocol and techniques for the restoration of noncarious Class V lesions and presents a clinical case in which esthetic restorations are achieved. CLINICAL SIGNIFICANCE: Treatment options for noncarious Class V lesions can range from simply eliminating the causative factors of the lesions and regularly monitoring their progression to specific restorative procedures. Resin composites are the best materials for restoring cervical defects owing to their bonding ability, physical properties, and esthetic potential. A straightforward technique for the successful restoration of noncarious Class V lesions is presented.

Clinical strategies for success in proximoincisal composite restorations. Part II: Composite application technique.

UNLABELLED: Reproducing the form, function, and optical characteristics of natural dental structures with direct composites in large and moderately large proximoincisal (Class IV) restorations represents a great challenge for clinicians in general. Understanding color is fundamental to achieving success when restoring these defects, as was discussed in Part I of this two-part article (Volume, 16, Number 6). The proper restoration of the functional lingual contour is also a challenge that cannot be overcome without close attention to the restorative technique. In this second article, the composite application technique is discussed and presented in detail. Clinical photographs illustrate the proposed technique. CLINICAL SIGNIFICANCE: The proposed clinical protocol, including a try-in of the shades in a mock-up restoration to more accurately define color and shape, and a silicone guide to transfer the lingual and proximoincisal contour of the mock-up to the final restoration, is of great help to successfully restore proximoincisal defects.

Dentin bond strength of self-etching primers/adhesives.

This study compared the shear bond strengths (SBS) to dentin achieved with six self-etching systems and one total-etch one-bottle adhesive system. Seventy freshly extracted bovine incisors were mounted in acrylic molds and the facial surfaces ground to expose middle dentin, which was polished by 600-grit sand paper. The incisors were randomly assigned to groups (n=10): Adper Prompt Self-Etch Adhesive, 3M-ESPE (ADP) and One-Up Bond F, Tokuyama (OU) as self-etching adhesives; AdheSE, Ivoclar-Vivadent (ADH), Clearfil SE Bond, Kuraray (SE), Optibond Solo Plus-Self-Etch, Kerr (OP) as self-etching primers, Tyrian SPE, BISCO (TY) as a self-priming etchant and Single Bond, 3M-ESPE (SB), a total-etch one-bottle adhesive served as a control. All adhesives were applied according to the manufacturers' instructions with the respective hybrid composites. The specimens were thermocycled for 500 cycles (5 degrees C to 55 degrees C), then loaded to failure in an Instron Universal Testing Machine at a crosshead speed of 0.5 mm/minute. Mean bond strengths were analyzed with one-way ANOVA, followed by a Duncan's post hoc test. SBS (mean +/- SD) were: ADH = 13.2 (+/- 5.3)b;ADP = 6.8 (+/- 4.4)c; OP = 18.2 (+/- 3.8)a; OU = 3.5 (+/- 1.5)c; SB = 12.2 (+/- 4.2)b; SE = 12.4 ( +/- 4.0)b; TY = 5.5 (+/- 1.4)c. Superscript letters indicate Duncan's homogeneous subsets. The self-etching adhesives OU and ADP and the self-priming etchant TY resulted in lower dentin SBS. OP resulted in the highest mean dentin SBS, while the other materials tested in this study (SE and ADH) presented similar dentin SBS to a total-etch one-bottle bonding system (SB).

Flowable composites as "filled adhesives:" a microleakage study.

OBJECTIVE: The purpose of this in vitro study was to investigate the microleakage at dentin margins of a flowable resin composite associated with an adhesive, either light cured separately or co-cured, in Class V cavities. MATERIALS AND METHODS: Twenty four recently extracted human molars were prepared with standardized box-shaped Class V cavities of 3.0 mm (mesial-distal), 2.0 mm (occlusal-gingival), and 2.0 mm depth with margins located on enamel and dentin/cementum on the buccal or lingual surfaces. The cavities were randomly assigned into three groups (n=8): Group I - Single Bond + Filtek Z250 (control); Group II - Single Bond + Filtek Flow (light cured separately) + Filtek Z250; and Group III - Single Bond + Filtek Flow co-cured (light cured simultaneously) + Filtek Z250. After being immersed in tap water for 24 h, the specimens were thermocycled (1000x, 5 degrees -55 degrees C, 30 sec dwell time) and immersed in a 0.5% basic fuchsine solution for 24 h. The restorations were sectioned longitudinally and gingival margins were evaluated for microleakage using a 0-4 scale. Data were subjected to the Kruskal-Wallis test at p<0.05. RESULTS: A statistically significant difference at p = 0.0044 between Groups 1 and 3 and Groups 2 and 3 was observed. Although Group 2 performed slightly better than Group 1, no significant difference was observed. CONCLUSION: The use of a flowable resin composite cured simultaneously with an adhesive yielded the worst results in this study. As no statistical differences were seen between Groups 1 and 2, the use of a flowable composite as a means of minimizing microleakage at dentin margins may be questioned.

Bonding to cervical sclerotic dentin: effect of acid etching time.

PURPOSE: The aim of this in vitro study was to evaluate the microtensile bond strengths (MTBS) of two total-etch one-bottle adhesive systems to natural cervical lesions with 2 different etching times (15 s vs 30 s). MATERIALS AND METHODS: Thirty-two human canines and premolars with saucer-shaped noncarious cervical defects were cleaned and randomly assigned to 4 groups. The adhesive systems - Single Bond (SB; 3M ESPE) or OptiBond Solo Plus (OP; Kerr) - were applied on cervical dentin after acid etching with the proprietary acid gel (35% or 37.5% phosphoric acid) for 15 s (manufacturer's instruction) or for 30 s. The respective hybrid composite was inserted in three increments and light cured. After 24 h water storage, the specimens were cut perpendicularly with a low-speed diamond saw (Isomet) to obtain slices with a cross section of ca 0.8 mm. After that, the slices were trimmed with a diamond bur to obtain a surface area of 0.7 +/- 0.05 mm2 (n = 12). MTBS was measured in a Bencor device with an Instron machine at a crosshead speed of 0.5 mm/min. The data were subjected to two-way ANOVA and Tukey's LSD post-hoc test (p < 0.05). RESULTS: MTBS are given in MPa (mean +/- SD), where means with the same superscript letter are not statistically different at p < 0.05: OP15 = 30.9 +/- 8.8ab, SB15 = 25.6 +/- 9.6bc, OP30 = 19.0 +/- 4.8c, SB30 = 35.9 +/- 11.0a. When data were pooled for "adhesive system", SB resulted in statistically higher bond strengths than OP (p < 0.043). "Acid etching time" had no significant effect (p < 0.766), but the interaction of the two main factors yielded significant differences (p < 0.0001). Extending etching time to 30 s resulted in a more predictable bond to noncarious cervical sclerotic dentin with SB, but resulted in lower MTBS with OP. CONCLUSION: Composite bonding to cervical sclerotic noncarious dentin may depend on acid demineralization capacity and bonding system. Knowing the etching demineralization rates of the commercially available acid etching seems to be an important factor for selecting the best acid-etching time of cervical sclerotic dentin.