Comparative in-vivo bond failure rate of orthodontic brackets when bracket base is treated with micro-abrasive blasting vs. acid etching: eighteen month randomized control trial and scanning electron microscope study.

Background: The aim of this study was threefold. Firstly, it aimed to introduce and detail a novel method for chemically etching the bases of stainless-steel orthodontic brackets. Secondly, the study sought to investigate the structural alterations within the brackets' microstructure following chemical etching compared to those with sandblasted bases, using electron microscopy analysis. Lastly, the study aimed to evaluate and compare the long-term durability and survivability of orthodontic brackets with chemically etched bases versus those with sandblasted bases, both bonded using the conventional acid etch technique with Transbond XT adhesive, over an 18-month follow-up period. Methods: The study was a randomized clinical control trial with triple blinding and split-mouth study design and consisted of two groups. The brackets in the sandblasted group were prepared by sandblasting the intaglio surface of the base of the bracket with 50 µm SiO2 particles. Hydrofluoric acid was used to roughen the base in the acid-etched group. The bases of the brackets were viewed under an electron microscope to analyze the topographical changes. Results: A total of 5,803 brackets (3,006 acid-etch, 2,797 sandblasted) in 310 patients were bonded, in a split-mouth design by the same operator. The patients were followed for 18 months. The failure rate of 2.59% and 2.7% was noted in an acid-etched and sandblasted group, respectively. There was a close approximation of curves in the Kaplan-Meier plot, and the survival distribution of the two groups in the log-rank (Mantel-Cox) test was insignificant; x2 = 0.062 (P value = 0.804). Conclusion: Acid etching if the bases of the brackets can be used as an alternative to sandblasting furthermore acid etching can be performed on the chair side.

EFFECTS OF ACID ETCHING ON COLOR CHANGES AND SURFACE MORPHOLOGY OF ENAMEL TO BE BLEACHED WITH DIFFERENT TECHNIQUES.

Aims - to compare the color changes, the surface roughness and morphology of the enamel bleached with two different bleaching solutions (chemical and laser activated), preceded or not with acid etching. Thirty teeth of bovine prepared and haphazardly assigned to 2 groups (n=15) depending on bleaching technique. Each group subdivided to 3 subgroup (n=5) consistent with acid etching by 37% phosphoric acid. Atomic force microscopy and VITA easy shade spectrophotometer were performed twice for all the specimens before and after bleaching. ANOVA, the Paired sample t-test, and the independent sample t-test used for statistical analysis. As for the color changes, the groups that were bleached by the chemical method, the difference among the three subgroups was statistically significant. This also applies to the groups bleached with the laser method. When comparing the results of the chemical bleaching subgroups with the laser bleaching ones, the difference was not significant. Roughness results showed significant differences between certain subgroups and non-significant differences among others. However, the difference was statistically significant between the chemical and laser groups, laser technique resulted in less surface roughness than the chemical one. Acid etching before bleaching produced better colour change in both the chemical and laser assisted bleaching. In chemical bleaching, surface roughness was higher when acid etching was used. This was also true for laser bleaching technique. In general, laser assisted bleaching produced less surface roughness than chemical bleaching.

The Selective Enamel Etch Technique.

Adhesive dentistry is an essential component in the delivery of direct and indirect restorations. Ongoing discussions among scientists and clinicians have focused on whether or not current self-etch and universal adhesives adequately prepare enamel surfaces to achieve optimal bond strengths. To address these concerns, a selective enamel etch technique has been recommended. The definition of a selective enamel etch technique is as its name suggests. The clinician selectively etches the enamel of a cavity preparation by applying phosphoric acid etchant to the enamel surfaces of the preparation while refraining from applying the etchant to the dentin. This article explores the current research to help guide clinicians to achieve ideal outcomes when using dental adhesives. With few exceptions, the current scientific evidence recommends a selective enamel etch technique in conjunction with the clinician's adhesive system of choice.

Reduction of surface treatment time by combination of citric acid and ascorbic acid while restoring shear bond strength of metal brackets bonded to bleached enamel: a pilot study.

BACKGROUND: To investigate the effect of a 50% ascorbic acid with 50% citric acid solution on the immediate shear bond strength (SBS) of metallic brackets after tooth bleaching. The enamel etching pattern and the required quantity of these combined acids as antioxidants following 35% hydrogen peroxide (HP) bleaching were also determined. METHODS: The stability of the solution at room temperature was assessed at various time intervals. Fifty teeth were randomly divided into five groups: non-bleached (G1), bleached then acid etched (G2), bleached followed by a 10-minute treatment with 10% sodium ascorbate and acid etched (G3), 5-minute treatment with 50% ascorbic acid (G4), and 5-minute treatment with a combination of 50% ascorbic acid and 50% citric acid (G5). Groups G2, G3, G4 and G5 were bleached by 35% HP gel for a total of 32 min. Acid etching in groups G1, G2, and G3 was performed using 37% phosphoric acid (Ormco®, Orange, CA, USA) for 15 s. In all groups, metal brackets were immediately bonded using Transbond™ XT primer and Transbond™ PLUS adhesive, with light curing for 40 s. The SBS was tested with a universal testing machine, and statistical analysis was conducted using one-way ANOVA followed by Tukey's HSD test. The level of significance was set at p < 0.05 for all statistical tests. RESULTS: Stability tests demonstrated that the combined acids remained effective for up to 21 days. Group G5 significantly increased the SBS of bleached teeth to the level of G1 (p < 0.05), while G3 did not achieve the same increase in SBS (p > 0.05). SEM analysis revealed enamel etching patterns similar to those of both control groups (G1 and G2). Kinetic studies at 6 min indicated that the antioxidation in G5 reacted 0.2 mmole lower than in G3 and G4. CONCLUSION: 5-minute application of the combined acids enhanced the SBS of bleached teeth comparable to unbleached teeth. The combined acids remain stable over two weeks, presenting a time-efficient, single-step solution for antioxidant application and enamel etching in orthodontic bracket bonding.

Comparison of Roughness, Wettability, and SEM Features between Sandblasted Acid-Etched and Oxidized Titanium Dental Implants.

The surface of dental implants has undergone multiple modifications across the timeline to enhance osseointegration, thereby enhancing the success of dental implants. This study compared the surface roughness, wettability and topography of sandblasted acid-etched, and oxidized titanium dental implants. Three commercially available implants-namely, SLA, SLActive, and TiUnite-were evaluated for surface roughness in terms of Ra, Rq, and Rz; wettability in terms of contact angle (CA); and topography using scanning electron microscopy (SEM). Roughness and wettability values were compared between the three surfaces by ANOVA and pairwise comparison by Tukey's HSD post hoc testing using SPSS Software. A p value of < 0.01 was considered to be statistically significant. The TiUnite surface exhibited the highest roughness values (Ra = 1.91 ± 0.006 µm, Rq = 2.99 ± 0.005 µm, Rz = 8.37 ± 0.003 µm) followed by the SLA and SLActive surfaces. The contact angles of the SLA, SLActive, and TiUnite dental implants were 98.44 ± 0.52°, 9 ± 0.03°, and 94.39 ± 0.08°, respectively. These data demonstrated statistically significant differences between the three surfaces (p < 0.01). There were no distinct differences in SEM features between the SLA and SLActive surfaces. However, the TiUnite surface exhibited a distinctly porous morphology. Oxidized dental implants differ from sandblasted acid-etched implants in terms of roughness, wettability, and surface topography.

A randomized controlled trial of immediate implant placement comparing hydroxyapatite nano-coated and uncoated sandblasted/acid-etched implants using a digital surgical guide.

PURPOSE: This study evaluated the implant stability, volumetric changes, and patient-reported outcome measures (PROMs) of hydroxyapatite (HA) nano-coated sandblasted/acid-etched (SLA) implants compared to uncoated SLA implants. METHODS: Forty patients were recruited and randomly allocated to HA nano-coated SLA group (test, n = 20) and uncoated SLA group (control, n = 20) using single-blinded/block randomization. Implants were immediately placed in maxillary posterior region using a digital surgical guide. Insertion torque and implant stability quotient (ISQ) were measured at implant surgery and 1, 2, 3, and 4 months postoperatively. Intraoral scans, PROMs and soft tissue inflammation data were collected, and multivariable linear regression analysis of ISQ was performed. RESULTS: In total, 48 implants (test; n = 24, control; n = 24) in 37 patients (test; n = 19, control; n = 18) were analyzed. Despite no significant between-group difference at surgery, the test group showed higher ISQ values than the control group at 2 (76.53 ± 4.17 vs. 71.32 ± 4.79, p < 0.01), 3 (77.45 ± 4.41 vs. 73.85 ± 4.69, p < 0.05), and 4 months (79.08 ± 2.96 vs. 73.43 ± 3.52, p < 0.0001) postoperatively. There were no significant differences in linear and volumetric changes, PROMs, and soft tissue inflammation analysis between two groups. The ISQ at implant surgery was influenced by age and diabetes mellitus (DM) at the implant level and DM and predicted total bone-to-implant contact area at the patient level. CONCLUSION: HA nano-coated SLA implants promoted favorable immediate implants stability during early osseointegration phase compared to uncoated SLA implants, but displayed similar dimensional changes, PROMs, and soft tissue inflammation outcomes. TRIAL REGISTRATION: Clinical Research Information Service (CRIS), KCT0006364. Registered 21 July 2021, https://cris.nih.go.kr/cris/search/detailSearch.do?seq=24221&search_page=L .

Effect of applying carbodiimide combined with a two-step self-etch adhesive durability.

BACKGROUND: This study investigated the effect of carbodiimide (EDC) combined with Clearfil SE self-etch adhesive on the shear bond strength (SBS), crosslinking degree, denaturation temperature, and enzyme activity of dentin in vitro. MATERIALS AND METHODS: Collected human sound third molars were randomly divided into different groups with or without EDC treatment (0.01-1 M). The specimens (n = 16)were stored for 24 h (immediate) or 12 months (aging) before testing the SBS. Fine dentin powder was obtained and treated with the same solutions. Then the crosslinking degree, denaturation temperature (Td), and enzyme activity were tested. Statistical analysis was performed using a one-way analysis of variance (ANOVA) to compare the differences of data between groups (α = 0.05). RESULTS: There was a significant drop in immediate SBS and more adhesive fracture of 1.0 M EDC group, while there were no significant differences among the other groups. SEM showed a homogeneous interface under all treatments. After 12 months of aging, the SBS significantly decreased. Less decreases of SBS in the 0.3 and 0.5 M groups were found. Due to thermal and enzymatical properties consideration, the 0.3 and 0.5 M treatments also showed higher cross-link degree and Td with lower enzyme activity. CONCLUSION: 0.3 and 0.5 M EDC may be favorable for delaying the aging of self-etch bond strength for 12 months. But it is still needed thoroughly study.

Ultrasonic activation of adhesive systems increases bond strength and intratubular penetration of resin cement in root dentin subjected to radiation therapy.

OBJECTIVE: This study aimed to evaluate the effect of ultrasonic activation of etch-and-rinse and self-etch adhesive systems on the bond strength of resin cement to irradiated root dentin. MATERIALS AND METHODS: Eighty human maxillary anterior teeth were distributed into 8 groups (n = 10), according to the type of adhesive system used (etch-and-rinse and self-etch), the ultrasonic activation of the adhesive systems, and the dentin condition (irradiated or non-irradiated - 70 Gy). Endodontic treatment was performed followed by fiberglass post-space preparation. After fiberglass posts' luting, the roots were transversely sectioned on dentin discs and submitted to the push-out bond strength test (0.5 mm/min). The fractured specimens were analyzed under a stereomicroscope and Scanning Electron Microscope (SEM) for failure mode classification. One of the dentin discs was analyzed under SEM to evaluate the characteristics of the adhesive interface. RESULTS: Irradiated specimens had lower bond strength than non-irradiated specimens (P < 0.0001). Ultrasonic activation of both adhesive systems increased the bond strength of the resin cement to irradiated dentin (P < 0.0001). Radiotherapy significantly affected the failure mode in the middle (P = 0.024) and apical thirds (P = 0.032) (adhesive failure). CONCLUSION: Non-irradiated specimens had a more homogeneous adhesive interface. When ultrasonically activated, both adhesive systems showed a greater number of resinous tags, regardless of the dentin condition. CLINICAL RELEVANCE: Ultrasonic activation of adhesive systems is a feasible strategy to enhance fiberglass posts retention in oncological patients.

Promotion of Dentin Biomimetic Mineralization and Bonding Efficacy by Interfacial Control of an Experimental Citric Acid Dental Etching Agent.

Resin-bonded restorations are the most important caries treatment method in clinical practice. Thus, improving the durability of dentin bonding remains a pressing issue. As a promising solution, guided tissue remineralization can induce the formation of apatite nanocrystals to repair defects in the dentin bonding interface. In this study, we present an experimental 20 wt % citric acid (CA) dental etching agent that removes the smear layer. After CA-etching, approximately 3.55 wt % residual CA formed a strong bond with collagen fibrils, reducing the interfacial energy between the remineralizing solution and dentin. CA helped achieve almost complete intrafibrillar and extrafibrillar mineralization after 24 h of mineralization. CA also significantly promoted poly(amidoamine)-induced dentin biomimetic mineralization. The elastic modulus and microhardness of remineralized dentin were restored to that of sound dentin. The remineralized interface reduced microleakage and provided a stronger, longer-lasting bond than conventional phosphate acid-etching. The newly developed CA dental etching agents promoted rapid dentin biomimetic mineralization and improved bonding efficacy through interfacial control, representing a new approach with clinical practice implications.

The Influence of Erbium Laser Pretreatment on Dentin Shear Bond Strength and Bond Failure Modes: A Systematic Review and Network Meta-Analysis.

PURPOSE: To systematically review in-vitro studies that evaluated the influence of erbium laser pretreatment on dentin shear bond strength (SBS) and bond failure modes. MATERIALS AND METHODS: Electronic databases (PubMed, Cochrane Central, Embase, and Web of Science) were searched. Only in-vitro studies involving erbium laser irradiation of the dentin surface and SBS testing of the bonded resin block were included. The three common modes of bond failure (1. adhesive, 2. cohesive, and 3. mixed) were observed and analyzed. The network meta-analysis (NMA) was performed by Stata 15.0 software, the risk of bias was evaluated, and the certainty of the evidence was assessed by the Confidence in Network Meta-analysis (CINeMA). RESULTS: Forty studies with nine pretreatments (1. blank group: BL; 2. phosphoric acid etch-and-rinse: ER; 3. self-etch adhesive: SE; 4. Er:YAG laser: EL; 5. Er,Cr:YSGG laser: ECL; 6. ER+EL; 7. ER+ECL; 8. SE+EL; 9. SE+ECL) were included in this analysis. The NMA of SBS showed that ER+EL [SMD = 0.32, 95% CI (0.11, 0.98)] had the highest SBS next to ER, especially when using one of the 3M ESPE adhesives, followed by EL, ECL, SE and SE+EL. The Ivoclar Vivadent adhesives significantly increased the SBS of the ECL [SMD = 0.37, 95% CI (0.16,0.90)] and was higher than ER+EL [SMD = 0.25,95% CI (0.07,0.85)]. Finally, the surface under the cumulative ranking curve (SUCRA) value indicated that ER+EL (SUCRA = 71.0%) and EL (SUCRA = 62.9%) were the best treatments for enhancing dentin SBS besides ER. ER+EL (SUCRA = 85.3%), ER (SUCRA = 83.7%) and ER (SUCRA = 84.3%) had the highest probability of occurring in adhesive, cohesive and mixed failure modes, respectively. CONCLUSION: Er:YAG and Er,Cr:YSGG lasers improved dentin SBS compared to the blank group, especially when the acid etch-and-rinse pretreatment was combined with Er:YAG laser. Shear bond strength and failure mode do not appear to be directly related.

Effect of hydroxyapatite nanoparticles coating of titanium surface on biofilm adhesion: An in vitro study.

AIM: To evaluate the adhesion of mono and duospecies biofilm on a commercially available dental implant surface coated with hydroxyapatite nanoparticles (nanoHA). MATERIAL AND METHODS: Titanium discs were divided into two groups: double acid-etched (AE) and AE coated with nanoHA (NanoHA). Surface characteristics evaluated were morphology, topography, and wettability. Mono and duospecies biofilms of Streptococcus sanguinis (S. sanguinis) and Candida albicans (C. albicans) were formed. Discs were exposed to fetal bovine serum (FBS) to form the pellicle. Biofilm was growth in RPMI1640 medium with 10% FBS and 10% BHI medium for 6 h. Microbial viability was evaluated using colony-forming unit and metabolic activity by a colorimetric assay of the tetrazolium salt XTT. Biofilm architecture and organization were evaluated by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). RESULTS: AE surface had more pores, while NanoHA had even nanoHA crystals distribution. Roughness was similar (AE: 0.59 ± 0.07 µm, NanoHA: 0.69 ± 0.18 µm), but wettability was different (AE: Θw= 81.79 ± 8.55°, NanoHA: Θw= 53.26 ± 11.86°; P = 0.01). NanoHA had lower S. sanguinis viability in monospecies biofilm (P = 0.007). Metabolic activity was similar among all biofilms. In SEM both surfaces on C. albicans biofilm show a similar distribution of hyphae in mono and duospecies biofilms. AE surface has more S. sanguinis than the NanoHA surface in the duospecies biofilm. CLSM showed a large proportion of live cells in all groups. CONCLUSIONS: The nanoHA surface reduced the adhesion of S. sanguinis biofilm but did not alter the adhesion of C. albicans or the biofilm formed by both species.

Does surface priming increase the bond strength of orthodontic brackets? An experimental study.

OBJECTIVE: To evaluate the effects of metal primer II (MP II) on the shear bond strength (SBS) of orthodontic brackets bonded to teeth and bis-acryl composite provisional material (Bis-Acryl). MATERIAL AND METHODS: Twenty extracted human premolars specimens and 20 premolar shaped Bis-Acryl specimens were obtained and randomly divided into two surface groups. The first group consisted of human premolars (T) bonded to brackets in the conventional way while in the second (T-MP) MP II was applied on the bracket base before bonding. Similarly, one group of provisional material (PM) was prepared according to conventional treatment and another with the application of MP-II metal bonder (PM-MP). In all cases Ortho-brackets (Victory Series, 3 M) were bonded employing Transbond XT resin cement. Then the brackets were debonded under shear and the results were statistically analyzed by two-way analysis of variance and Holm Sidak at α = .05. The debonded surfaces of all specimens were examined by light microscopy and the Adhesive Remnant Index (ARI) was recorded. RESULTS: The SBS results exhibited significant differences er (p < .001). For both the T and TM the application of MP-II increased the SBS compared to respective control groups (p < .001). The T-C group was found inferior compared to PM-C (p < .001) and the same is true for the comparison between T-MP and PM-MP (p < .001). ARI indexes demonstrated that the tooth groups were characterized by a predominantly adhesive failure at the resin-dentin interface. In contrast, the control group for provisional crowns (PM-C) showed a predominantly cohesive failure mode, which moved to predominantly adhesive after the application of MP II. CONCLUSION: The application of MP II enhances the SBS on both, human enamel and provisional crown materials.

Effect of low power Er:YAG laser irradiation of CAD-CAM resin-based composites on resin bonding.

PURPOSE: To investigate the effect of painless low-power Er:YAG laser irradiation of conventional and polymer-infiltrated ceramic network (PICN) type CAD-CAM resin-based composites (RBCs) on resin bonding. METHODS: An Er:YAG laser system, phosphoric acid etchant, universal adhesive, RBC, and two types of CAD-CAM RBC block were used. Microtensile bond strength, fracture mode, scanning electron microscopy (SEM) observations of bonding interfaces and CAD-CAM surfaces, and surface roughness of ground and pretreated surfaces were investigated. As pretreatment methods, low-power Er:YAG laser irradiation and air-abrasion with alumina particles were used. RESULTS: The effect of low-power Er:YAG laser irradiation of CAD-CAM RBCs on bonding to repair resin varied depending on the type of CAD-CAM RBCs. CLINICAL SIGNIFICANCE: The low-power Er:YAG laser irradiation of the conventional CAD-CAM RBCs was shown to be effective as a surface pretreatment for resin bonding, while the laser irradiation of PICN-type CAD-CAM RBCs was not effective.

Effect of surface treatment and resin cement type on the bond strength of polyetheretherketone to lithium disilicate ceramic.

BACKGROUND: This study aims to evaluate the effect of surface treatment and resin cement on the shear bond strength (SBS) and mode of failure of polyetheretherketone (PEEK) to lithium disilicate ceramic (LDC). This is suggested to study alternative veneering of PEEK frameworks with a ceramic material. METHODS: eighty discs were prepared from PEEK blank and from lithium disilicate ceramic. Samples were divided into four groups according to surface treatment: Group (A) air abraded with 110 µm Al2O3, Group (AP) air abrasion and primer application, Group (S) 98% sulfuric acid etching for 60 s, Group (SP) Sulfuric acid and primer. Each group was subdivided into two subgroups based on resin cement type used for bonding LDC:1) subgroup (L) self- adhesive resin cement and 2) subgroup (B) conventional resin cement (n = 10). Thermocycling was done for all samples. The bond strength was assessed using the shear bond strength test (SBS). Failure mode analysis was done at 50X magnification with a stereomicroscope. Samples were chosen from each group for scanning electron microscope (SEM). The three-way nested ANOVA followed by Tukey's post hoc test were used for statistical analysis of results. Comparisons of effects were done utilizing one way ANOVA and (p < 0.05). RESULTS: The highest mean of shear bond strength values was demonstrated in Group of air abrasion with primer application using conventional resin cement (APB) (12.21 ± 2.14 MPa). Sulfuric acid groups showed lower shear bond strength values and the majority failed in thermocycling especially when no primer was applied. The failure mode analysis showed that the predominant failure type was adhesive failure between cement and PEEK, while the remaining was mixed failure between cement and PEEK. CONCLUSION: The air abrasion followed by primer application and conventional resin cement used for bonding Lithium Disilicate to PEEK achieved the best bond strength. Primer application did not have an effect when self-adhesive resin cement was used in air-abraded groups. Priming step is mandatory whenever sulfuric acid etching surface treatment is utilized for PEEK.

Evaluation of Fibrin Clot Interaction with Dental Implant after Different Surface Treatments: An In Vitro Study.

AIM: The current study was carried out to assess the interaction between fibrin clots and dental implants following various surface treatments. MATERIALS AND METHODS: In this investigation, 45 dental implants with dimensions of 16 mm in length and 5 mm in diameter were utilized. They were divided up into three groups, each consisting of fifteen samples. Group I: Control; Group II: Ultraviolet (UV) light treated; and group III: Sandblasted and acid-etching (SLA) treated. Healthy volunteers' venous blood samples were drawn into vacutainer tubes without the use of anticoagulants. The samples were centrifuged for 3 minutes at 2700 rpm in a table centrifuge. The entire implant was submerged in room-temperature liquid fibrinogen for 60 minutes. Then, scanning electronic microscopy (SEM) was used to examine each sample. The inter- and intragroup assessments were obtained using the Mann-Whitney U test and the Kruskal-Wallis test; p-values less than 0.05 were regarded as statistically significant. RESULTS: The maximum adhesion of fibrin clot was found in SLA treated group (2.42 ± 0.10) followed by the UV light-treated group (2.18 ± 0.08) and control group (1.20 ± 0.02). There was a statistically significant difference found between the three surface-treated groups (p < 0.001). CONCLUSION: All surface-treatment methods exhibit adhesion between the implant surface and the fibrin clot. However, the highest adherence of fibrin clot was found in SLA treated group compared to the UV light-treated and control group. CLINICAL SIGNIFICANCE: The physical and chemical characteristics of an implant's surface have a significant impact on the way blood clots organize. At the interface between the implant and the bone, blood clot production can initiate and facilitate the healing process. How to cite this article: Jalaluddin M, Ramanna PK, Swain M, et al. Evaluation of Fibrin Clot Interaction with Dental Implant after Different Surface Treatments: An In Vitro Study. J Contemp Dent Pract 2024;25(3):276-279.

Influence of Varied Silane Commercial Brands and Adhesive Application on Bond Strength and Stability to Lithium Disilicate Glass Ceramic.

OBJECTIVES: This study aimed to evaluate the impact of various commercial silane brands with varied chemical compositions with or without the application of an adhesive layer on the microshear bond strength and durability of a resin luting agent to lithium disilicate glass ceramic. METHODS AND MATERIALS: Lithium disilicate glass ceramic discs (EMX, IPS e.max Press, Ivoclar Vivadent) measuring 10 mm in diameter and 3 mm in thickness were fabricated (n=240). Surfaces were etched using 5% hydrofluoric acid and randomly assigned to 10 groups based on the commercial brand of silane used (n=24): [RP] RelyX Ceramic Primer (3M ESPE); [PS] Prosil (FGM); [SA] Silano (Angelus); [SM] Silano (Maquira); [SU] Silane (Ultradent); [GL] GLUMA Ceramic Primer (Kulzer); [CB] Ceramic Bond (VOCO); [MB] Monobond N (Ivoclar Vivadent); [CP] Clearfil Ceramic Primer (Kuraray); and [DE] 2-step silane (Dentsply Sirona). Half of the EMXs (n=12) received a thin adhesive layer (+) after the silane and prior to resin luting agent, while the other half (n=12) did not receive an adhesive layer (-). For the microshear bond strength test (µSBS), four light-cured resin luting agent cylinders (1 mm in diameter) were created on each EMX surface. Half of these specimens were tested after 24 hours, while the other half were stored in deionized water for 6 months. The µSBS test was conducted using a universal testing machine (DL 500, EMIC) at a crosshead speed of 1 mm/min until failure. The obtained data underwent statistical analysis using analysis of variance (ANOVA) and the Tukey test (α=0.05). RESULTS: There was significant influence of the silane commercial brand on bond strength. Notably, "universal primers" yielded lower bond strength results compared to "pure" silane solutions. Water storage had a detrimental effect on microshear bond strength for certain silane commercial brands. Additionally, the application of an adhesive layer negatively impacted bond strength results for all silanes. CONCLUSIONS: This study confirms the importance of both silane commercial brand and chemical composition in relation to bond strength of resin luting agents to lithium disilicate glass ceramic. Furthermore, the application of an adhesive layer may have an adverse effect on bond stability over time.

Effects of different primers and colouring solutions on orthodontic bonding: shear bond strength and colour change.

OBJECTIVES: This in vitro study evaluated the effect of different colouring solutions and primer systems used in the bonding of brackets on enamel colour change and bond strength. MATERIALS AND METHODS: 120 premolar teeth were divided into four main groups; brackets were bonded with 37% orthophosphoric acid + Transbond XT Primer in Group 1, 3 M Single Bond Universal in Group 2, Transbond Plus SEP in Group 3, and G-Premio Bond in Group 4. Each group was divided into three subgroups, and the teeth were placed in a cup containing coffee and tea mixture, in a cup containing cola and in distilled water. A bond strength test was applied to all teeth. Colour measurements of all teeth were performed at 2 different times: before bonding and after the bond strength test. RESULTS: The average bond strength of the 37% orthophosphoric acid group was higher than that of the other groups. The effect of primer and solution groups on colour change was statistically significant (p = 0.001 and p = 0.023, respectively). CONCLUSIONS: In this study, the bond strength was clinically sufficient in all primer groups. The highest colour change was observed when the tea-coffee solution and Transbond Plus SEP primer were used. CLINICAL RELEVANCE: This study has identified enamel discoloration and bond strength from different colouring solutions and primer systems used for bonding braces, which can be used to inform clinicians and patients to achieve better treatment results.

Effect of Salvadora persica on resin-dentin bond stability.

BACKGROUND: The stability of resin-dentin interfaces is still highly questionable. The aim of this study was to evaluate the effect of Salvadora persica on resin-dentin bond durability. MATERIALS AND METHODS: Extracted human third molars were used to provide mid-coronal dentin, which was treated with 20% Salvadora persica extract for 1 min after acid-etching. Microtensile bond strength and interfacial nanoleakage were evaluated after 24 h and 6 months. A three-point flexure test was used to measure the stiffness of completely demineralized dentin sticks before and after treatment with Salvadora persica extract. The hydroxyproline release test was also used to measure collagen degradation by endogenous dentin proteases. Statistical analysis was performed using two-way ANOVA followed by post hoc Bonferroni test and unpaired t-test. P-values < 0.05 were considered statistically significant. RESULTS: The use of Salvadora persica as an additional primer with etch-and-rinse adhesive did not affect the immediate bond strengths and nanoleakage (p > 0.05). After 6 months, the bond strength of the control group decreased (p = 0.007), and nanoleakage increased (p = 0.006), while Salvadora persica group showed no significant difference in bond strength and nanoleakage compared to their 24 h groups (p > 0.05). Salvadora persica increased dentin stiffness and decreased collagen degradation (p < 0.001) compared to their controls. CONCLUSION: Salvadora persica extract pretreatment of acid-etched dentin preserved resin-dentin bonded interface for 6 months. CLINICAL SIGNIFICANCE: Durability of resin-dentin bonded interfaces is still highly questionable. Endogenous dentinal matrix metalloproteinases play an important role in degradation of dentinal collagen within such interfaces. Salvadora persica may preserve resin-dentin interfaces for longer periods of time contributing to greater clinical success and longevity of resin composite restorations.

Influence of etching mode on bonding performance of self-adhesive flowable resin composites to bovine teeth.

This study aimed to evaluate the bonding performance of self-adhesive flowable resin composites (SARs) to bovine teeth. Three SARs, one experimental, and two commercially available products, were used. The study parameters were shear bond strength (SBS), microleakage, and scanning electron microscopy (SEM) evaluation of bonding interfaces. The SBS of the materials was 14.1-15.1 MPa to enamel, 22.2-23.2 MPa to etched enamel, and 7.4-10.7 MPa to dentin. Specimens with pre-etching showed lower microleakage scores than those without pre-etching. SEM images of the interfaces of the materials showed excellent adaptation regardless of the substrate or etching mode. The study results indicate that enamel pre-etching can improve the bonding performance of SARs.