Customized Fiber Post Improves the Bond Strength and Dentinal Penetrability of Resin Cementation System to Root Dentin

SUMMARY Objective: This study aimed to evaluate the effect of fiber post customization on the bond strength (24 hours and 6 months), resin cement thickness, and dentinal penetrability of Adper Scotchbond Multi-Purpose – RelyX ARC (AS-RA), RelyX U200 (R2), and Scotchbond Universal – RelyX Ultimate (SU-RU) cementation systems to root dentin from the cervical-, middle-, and apical-thirds of the post space. Methods: One hundred twenty bovine incisors were endodontically treated. After post space preparation, the roots were divided into six groups, according to the luting protocols (AS–RA, R2, SU– RU) and the type of fiber post [noncustomized post (NC) and customized post (C)]. Customization procedures were peformed using a resin composite (Z350 XT). 24 hours (n=60) or 6 months later (n=60), specimens from the cervical-, middle-, and apical-thirds of the post space were submitted to cementation system thickness measurement, bond strength evaluation, and dentinal penetrability analysis with Confocal Laser Scanning Microscopy (CLSM). Failure mode was classified as adhesive, cohesive, or mixed. Data were submitted to ANOVA and Tukey tests (α=0.05). Results: Cementation protocols with customized fiber posts presented the lowest cementation system thickness, regardless of the cementation system or post space-third (p<0.05), and the highest bond strength values (p<0.05), regardless of the third space (p>0.05), for both periods (24 hours or 6 months). The comparison of push-out bond strength values between 24 hours and 6 months showed a reduction in all groups for the cervical-third (p<0.05). For the middle-third, only noncustomized groups showed reduction (p<0.05). For the apical-third, no reduction was observed (p>0.05). Conclusions: Anatomical customization favored both the bond strength of cements to dentin and the dentinal penetrability, but with lower cementation system thickness, regardless of cement composition and adhesive strategy.

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Relined Fiberglass Post: Effect of Luting Length, Resin Cement, and Cyclic Loading on the Bond to Weakened Root Dentin

Operative Dentistry ◽

10.2341/15-233-l ◽

2016 ◽

Vol 41 (6) ◽

pp. e174-e182 ◽

Cited By ~ 3

Author(s):

NC de Souza ◽

ML Marcondes ◽

DFF da Silva ◽

GA Borges ◽

LH Burnett Júnior ◽

...

Keyword(s):

Cyclic Loading ◽

Bond Strength ◽

Laser Scanning ◽

Testing Machine ◽

Resin Cement ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Pull Out ◽

Anterior Teeth ◽

Bond Interface

SUMMARY This study evaluated the effects of luting length of the post, the resin cement, and cyclic loading on pull-out bond strength of fiberglass posts relined with composite resin in weakened roots. The canals of 80 bovine incisors were endodontically treated and weakened with diamond burs. The teeth were randomly divided into eight groups (n=10) according to the luting procedures of the relined fiberglass post (RFP): In groups 1, 2, 3, and 4, the RFPs were luted with RelyX ARC, and in groups 5, 6, 7, and 8 they were luted with RelyX U200. In groups 1, 3, 5, and 7, the RFPs were luted at a length of 5 mm, and in groups 2, 4, 6, and 8 they were luted at a length of 10 mm. Specimens from groups 3, 4, 7, and 8 were submitted to cyclic loading. Specimens were subjected to a pull-out bond strength test in a universal testing machine. The results (MPa) were analyzed by three-way analysis of variance and the Tukey post hoc test (α=0.05). Six human upper anterior teeth were used to analyze the bond interface by confocal laser scanning microscopy (CLSM). The pull-out bond strength of RFPs luted with RelyX U200 was statistically higher than that of RelyX ARC. Cyclic loading influenced the bond strength only for the luting length of 5 mm. CLSM analysis revealed the formation of resin cement tags for both materials. Luting length is an important factor in retaining RFPs in weakened roots when they are subjected to cyclic loading, and RelyX U200 resulted in greater bond strengths to the root canal in comparison with RelyX ARC.

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Bonding Performance of Universal Adhesives Applied to Nano-Hydroxyapatite Desensitized Dentin Using Etch-and-Rinse or Self-Etch Mode

Materials ◽

10.3390/ma14164746 ◽

2021 ◽

Vol 14 (16) ◽

pp. 4746

Author(s):

Yuchen Meng ◽

Fan Huang ◽

Silin Wang ◽

Meiwen Li ◽

Yi Lu ◽

...

Keyword(s):

Bond Strength ◽

Laser Scanning ◽

Resin Composite ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Bonding Performance ◽

Etch And Rinse ◽

Significant Difference ◽

Universal Adhesives ◽

Self Etch

The study assessed the bonding performance of three universal adhesives on desensitized dentin with etch-and-rinse mode or self-etch mode after nano-hydroxyapatite (nHAp)-based desensitizers application. Simulated sensitive dentin specimens were prepared and separated into four groups: no treatment as the negative control, groups desensitized by Biorepair toothpaste, Dontodent toothpaste, or nHAp paste. Three universal adhesives of All-Bond Universal, Single Bond Universal, and Clearfil Universal Bond with etch-and-rinse or self-etch mode were bonded to the desensitized dentin specimens separately, followed by resin composite build-ups. Micro-tensile bond strength was measured using a micro-tensile tester. The wettability of desensitized dentin was evaluated by the contact angle of the adhesives. Resin infiltration was observed by confocal laser scanning microscopy. Dentin tubular occlusion and nanoleakage were observed by scanning electron microscope. The results showed that the etch-and-rinse or self-etch mode of each adhesive showed similar bond strength when bonding to nHAp-based desensitized dentin. The dentin surface was partially covered by desensitizers after desensitization. Compared with the self-etch mode, stronger demineralization and more reopened dentin tubules were observed in the etch-and-rinse mode after acid etching; longer resin tags and more nanoleakage in the resin–dentin interface were observed when using the etch-and-rinse mode. When bonding to nHAp-based desensitized dentin with universal adhesives, no significant difference in bond strength was found between self-etch mode or etch-and-rinse mode; while the latter produced more nanoleakage in the resin–dentin interfaces.

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Different biomechanical preparation protocols on the penetration and bond strength of the filling material to dentin

Brazilian Dental Journal ◽

10.1590/0103-6440202104472 ◽

2021 ◽

Vol 32 (5) ◽

pp. 12-22

Author(s):

Luciana Martins Domingues de Macedo ◽

Yara Teresinha Corrêa Silva-Sousa ◽

Orestes Olivato Junior ◽

Adrielle Fracaroli Baltazar ◽

Fuad Jacob Abi Rached-Junior

Keyword(s):

Bond Strength ◽

Laser Scanning ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Filling Material ◽

Ah Plus ◽

Irrigation Solution ◽

Ultrasonic Irrigation ◽

Root Dentin ◽

Push Out

Abstract The aim of this study was to evaluate the influence of different instruments and mechanisms of agitation of the irrigating solution on the penetration by confocal laser scanning microscopy (CLSM), and the bond strength (BS) of the filling material to the dentin by push-out test. Human premolars were distributed in two experimental groups (n=30), according to the instrumentation system: ProTaper Next (PN) or XP-endo Shaper (XS) and three irrigation protocol (n=10): NaviTip (Nv), XP-endo Finisher (XF), passive ultrasonic irrigation/ XP-endo Finisher (PUIXF). The 2.5% NaOCl and 17% EDTA were the irrigating solutions used. The filling was performed using a lateral condensation technique, with AH Plus added to 0.1% rodhamine B. The roots were sectioned, obtaining 2 slices for each third of the root. The first slice was submitted to the sealer penetration analysis and the push-out test. The second slice was submitted to qualitative analysis (SEM) of the union interface. For the penetration (%) Tukey showed that PNXF (82.38±13.48), PNPUIXF (82.48± 12.02), XSXF (82.24±11.28) and XSPUIXP (86.23±10.45) presented the highest values, different (p<0.05) from PNNv (68.29±15.12) and XSNv (71.41±16.50). The BS (MPa) test evidenced that in the cervical third, PNPF (4.92±1.04) and XPSPF (5.03±0.70) obtained the highest values differing from the others groups (p<0.05). CSLM and SEM showed greater penetration of the sealer on the entire length of the root canal when the irrigation solution was stirred. In conclusion that the association PUI and XP-endo Finisher favored the penetration and bond strength of the filling material to the root dentin.

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Micromorphological analysis and bond strength comparison of two adhesives for different degrees of dental fluorosis

10.21203/rs.3.rs-16637/v3 ◽

2020 ◽

Author(s):

Shuangfeng Liu ◽

Yanxia Zhu ◽

Tana Gegen

Keyword(s):

Shear Strength ◽

Bond Strength ◽

Bonding Strength ◽

Laser Scanning ◽

Dental Fluorosis ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Cohesive Failure ◽

Bonding System ◽

Significant Difference

Abstract The objective of this study was to analyze morphologically the all-etching bonding system and self-etching bonding system for enamel with different degrees of fluorosis and evaluate the bond strength of each system. Teeth that were indicated for extraction owing to orthodontic or periodontal problems were selected. According to Dean’s index and the Thylstrup-Fejerskov index, 180 extracted teeth were divided into three groups of mild, moderate, and severe dental fluorosis (DF), with 60 teeth in each group. The teeth in each group were randomly divided into two subgroups (n = 30), which were then subjected to the all-etching bonding system (Prime & Bond NT) and self-etching bonding system (SE-Bond). Each group of adhesives was used to bond Z350 universal resin (3M) to the etched dental enamel. Tensile and shear tests were conducted to determine the bond strength. Subsequently, the fractured specimens were investigated using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The Prime & Bond NT was statistically significant for the tensile and shear strength of enamel with mild fluorosis (P < 0.05) but did not exhibit a significant difference for moderate and severe DF (P > 0.05). The SE-Bond was not statistically significant for the tensile and shear strength of mild, moderate, or severe DF (P > 0.05). The SEM and CLSM results reveal that the mild fluorosis enamel crystals were relatively dense, and a small amount of resin remained. The moderate fluorosis enamel crystals were loosely arranged, and the gaps were widened. The severe fluorosis enamel crystals were irregularly arranged. The disorder was aggravated, and the dentinal orifice was exposed by partial enamel exfoliation. The bonding strength of mild fluorosis enamel with the Prime & Bond NT was better than that with the SE-Bond, and cohesive failure was the most common mode of failure. Because there was no difference in the bonding strength of the SE-Bond for different degrees of DF, we recommend the use of the all-etching adhesive system in the clinical treatment of teeth with mild fluorosis.

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Triacrylamide-Based Adhesives Stabilize Bonds in Physiologic Conditions

Journal of Dental Research ◽

10.1177/00220345211061736 ◽

2022 ◽

pp. 002203452110617

Author(s):

F.S. de Lucena ◽

S.H. Lewis ◽

A.P.P. Fugolin ◽

A.Y. Furuse ◽

J.L. Ferracane ◽

...

Keyword(s):

Bond Strength ◽

Cross Sections ◽

Laser Scanning ◽

Adhesive System ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Gap Formation ◽

Bond Stability ◽

Occlusal Surfaces ◽

Before And After

In this study, an acrylamide-based adhesive was combined with a thiourethane-based composite to improve bond stability and reduce polymerization stress, respectively, of simulated composite restorations. The stability testing was conducted under physiologic conditions, combining mechanical and bacterial challenges. Urethane dimethacrylate was combined with a newly synthesized triacrylamide (TMAAEA) or HEMA (2-hydroxyethyl-methacrylate; control) to produce a 2-step total-etch adhesive system. Methacrylate-based composites (70 wt% silanized filler) were formulated, containing thiourethane oligomers at 0 (control) or 20 wt%. Standardized preparations in human third molars were restored; then, epoxy replicas were obtained from the occlusal surfaces before and after 7-d storage in water or with Streptococcus mutans biofilm, which was tested after storage in an incubator (static) or the bioreactor (mechanical challenge). Images were obtained from the replicas (scanning electron microscopy) and cross sections of the samples (confocal laser scanning microscopy) and then analyzed to obtain measurements of gap, bacterial infiltration, and demineralization. Microtensile bond strength of specimens stored in water or biofilm was assessed in 1-mm2 stick specimens. Data were analyzed with analysis of variance and Tukey’s test (α = 0.05). HEMA-based materials had greater initial gap measurements, indicating more efficient bonding for the acrylamide materials. When tested in water, the triacrylamide-based adhesive had smaller gaps in the incubator or bioreactor. In the presence of biofilm, there was less difference among materials, but the acrylamide/thiourethane combination led to statistically lower gap formation in the bioreactor. HEMA and TMAAEA-based adhesives produced statistically similar microtensile bond strengths after being stored in water for 7 d, but after the same period with biofilm-challenged specimens, the TMAAEA-based adhesives were the only ones to retain the initial bond strength values. The use of a stable multiacrylamide-based adhesive led to the preservation of the resin-dentin bonded interface after a physiologically relevant challenge. Future studies will include a multispecies biofilm model.

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Analysis of Shear Bond Strength and Morphology of Er:YAG Laser-Recycled Ceramic Orthodontic Brackets

BioMed Research International ◽

10.1155/2016/7276287 ◽

2016 ◽

Vol 2016 ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

Ruo-qiao Han ◽

Kai Yang ◽

Ling-fei Ji ◽

Chen Ling

Keyword(s):

Bond Strength ◽

Shear Bond Strength ◽

Laser Scanning ◽

Er:Yag Laser ◽

Statistical Significance ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Control Group ◽

Test Machine ◽

Ceramic Brackets

Objective. The aim of this study was to compare the recycling of deboned ceramic brackets via an Er:YAG laser or via the traditional chairside processing methods of flaming and sandblasting; shear bond strength and morphological changes were evaluated in recycled brackets versus new brackets.Materials and Methods. 3M Clarity Self-Ligating Ceramic Brackets with a microcrystalline base were divided into groups subjected to flaming, sandblasting, or exposure to an Er:YAG laser. New ceramic brackets served as a control group. Shear bond strengths were determined with an Electroforce test machine and tested for statistical significance through analysis of variance. Morphological examinations of the recycled ceramic bracket bases were conducted with scanning electron microscopy and confocal laser scanning microscopy. Residue on the bracket base was analyzed with Raman spectroscopy.Results. Faded, dark adhesive was left on recycled bracket bases processed via flaming. Adhesive was thoroughly removed by both sandblasting and exposure to an Er:YAG laser. Compared with new brackets, shear bond strength was lower after sandblasting (p<0.05), but not after exposure to an Er:YAG laser. The Er:YAG laser caused no damage to the bracket.Conclusion. Er:YAG lasers effectively remove adhesive from the bases of ceramic brackets without damaging them; thus, this method may be preferred over other recycling methods.

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Influence of the Resin Cement Thickness on the Push-Out Bond Strength of Glass Fiber Posts

Brazilian Dental Journal ◽

10.1590/0103-6440201600886 ◽

2016 ◽

Vol 27 (5) ◽

pp. 592-598 ◽

Cited By ~ 7

Author(s):

Regina Maria Helen-Cot Marcos ◽

◽

Gustavo Ross Kinder ◽

Edson Alfredo ◽

Tarcisio Quaranta ◽

...

Keyword(s):

Bond Strength ◽

Glass Fiber ◽

Resin Composite ◽

Resin Cement ◽

Distilled Water ◽

Cement Layer ◽

Fiber Posts ◽

Glass Fiber Posts ◽

Post Space ◽

Push Out

Abstract The objective of the present study was to evaluate the influence of resin cement thickness on the bond strength of prefabricated and customized glass fiber posts after storage in distilled water. Thirty human uniradicular roots were treated endodontically. The roots were divided into 3 groups: THIN (thin cement layer) - post space preparation with #0.5 drill and cementation of #0.5 post; THICK (thick cement layer) - post space preparation with #1 drill and cementation of #0.5 post; and CUSTOM (customized cement layer) - post space preparation with #1 drill and cementation of a customized post (#0.5 glass fiber posts customized with resin composite). All posts were luted with self-adhesive resin cement. The push-out test was carried out after storage for 24 h and 90 days in distilled water at 37 °C. The data were analyzed with three-way ANOVA and Tukey's test (a=0.05). Bond strengths were significantly higher for CUSTOM (9.37 MPa), than for THIN (7.85 MPa) and THICK (7.07 MPa), which were statistically similar. Considering the thirds, the bond strength varied in the sequence: apical (7.13 MPa) < middle (8.22 MPa) = coronal (8.94 MPa). Bond strength for 24 h storage was significantly higher (8.80 MPa) than for 90-day storage (7.40 MPa). It may be concluded that the thickness of resin cement influenced the bond strength of glass fiber posts. The customized posts presented higher bond strength. Storage in water for 90 days affected negatively the values of bond strength, especially for thick cement layers in the apical third.

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Effect of Etching Procedures on the Adhesion of Biofilm-Coated Dentin

Materials ◽

10.3390/ma13122762 ◽

2020 ◽

Vol 13 (12) ◽

pp. 2762

Author(s):

Bo-Kyung Jeon ◽

Chang-Ha Lee ◽

A Reum Kim ◽

Seung Hyun Han ◽

Hyun-Jung Kim ◽

...

Keyword(s):

Bond Strength ◽

Biofilm Formation ◽

Laser Scanning ◽

Failure Modes ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Acid Etching ◽

Dentin Surface ◽

Biofilm Removal ◽

Oral Biofilms

Oral biofilms coat all surfaces in the oral cavity including the exposed dentin surface. This study aimed to investigate biofilm removal by acid etching procedures and the effects of the residual biofilm on dentin surfaces on composite–dentin adhesion. Dentin discs were assigned to five groups: no biofilm formation (C); biofilm formation and no surface treatment (BF); biofilm formation and acid etching (BF-E); biofilm formation and acid etching followed by chlorhexidine soaking (BF-EC); and biofilm formation and rubbing with pumice, followed by acid etching (BF-RE). Biofilms were formed on saliva-precoated dentin discs by soaking the discs in Streptococcus mutans (S. mutans) suspension. Biofilm removal from the dentin surface was evaluated quantitatively and qualitatively by confocal laser scanning microscopy and scanning electron microscopy, respectively. To compare the bond strength of the biofilm-coated dentin discs with the surface treatments, specimens were assigned to four groups: no biofilm formation and acid etching (C-E); BF-E; BF-EC; and BF-RE. Assessments of the micro-shear bond strength and subsequent failure modes were performed. BF-E and BF-EC did not remove the biofilm, whereas BF-RE partially removed the biofilm attached to the dentin (p < 0.05). The bond strength of BF-RE was significantly higher than those of BF-E and BF-EC, but lower than that of C-E (p < 0.05). In conclusion, mechanical biofilm removal is recommended before etching procedures to enhance adhesion to the biofilm-coated dentin.

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Influence of Sealer and Light-Curing Units on Push-Out Bond Strength Of Composite Resin to Weakened Roots

Brazilian Dental Journal ◽

10.1590/0103-6440201601010 ◽

2016 ◽

Vol 27 (4) ◽

pp. 430-435 ◽

Cited By ~ 4

Author(s):

Adriana Corrêa de Lima ◽

Fuad Jacob Rached-Junior ◽

Natália Spadini de Faria ◽

Danielle Cristine Messias ◽

Carolina de Andrade Lima Chaves ◽

...

Keyword(s):

Bond Strength ◽

Composite Resin ◽

Resin Composite ◽

Laser Scanning Microscopy ◽

Cervical Region ◽

Confocal Laser ◽

Filling Material ◽

Ah Plus ◽

Light Curing ◽

Push Out

Abstract The aim of this study was to assess the influence of sealer and light-curing unit on regional bond strength of resin composite to the weakened roots. Ninety roots of incisors were experimentally weakened, subjected to biomechanical preparation and filled with either Endofill, AH Plus or MTA Fillapex The roots were desobturated e reinforced with resin composite and fiber post light-activated with one of the light sources: halogen at 600 mW/ cm2 (QTH-600), LED at 800 mW/ cm2 (LED-800) and LED at 1500 mW/ cm2 (LED-1500). The roots were sectioned in slices from cervical, middle and apical root-reinforcement regions and analyzed by push out test, scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Bond strength data were analyzed using three-way ANOVA and Tukey´s test (α=0.05). Specimens filled with AH Plus had higher bond strength, followed by MTA Fillapex and Endofill (p<0.05). For light-curing unit, LED-1500 presented superior bond strength than LED-800, which was higher than QTH-600 (p<0.05). The cervical region had the greatest mean values (p<0.05) while apical part showed the lowest bond strength (p<0.05). CLMS revealed remaining filling material in the dentinal tubules for all groups. The eugenol-containing sealer (Endofill) compromised the push-out bond strength of composite resin to the root dentin. Bond strength was favored in the cervical region, and when LED-1500 was used.

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Bacterial Colonization in the Marginal Region of Ceramic Restorations: Effects of Different Cement Removal Methods and Polishing

Operative Dentistry ◽

10.2341/15-206-l ◽

2016 ◽

Vol 41 (6) ◽

pp. 642-654 ◽

Cited By ~ 5

Author(s):

SMB Pereira ◽

LC Anami ◽

CA Pereira ◽

ROA Souza ◽

KZ Kantorski ◽

...

Keyword(s):

Laser Scanning ◽

Bacterial Colonization ◽

Resin Cement ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Significant Difference ◽

Ceramic Blocks ◽

Cement Removal ◽

Ceramic Restorations ◽

Marginal Region

SUMMARY This study evaluated the effects of excess cement removal techniques, with or without subsequent polishing, on biofilm formation and micromorphology in the marginal region of the tooth/restoration. From bovine teeth, 96 dentin blocks (4 × 8 × 2 mm) were produced, molded, and reproduced in type IV gypsum, on which 96 pressed ceramic blocks (Vita PM9, Vita Zahnfabrik; 4 × 8 × 2 mm) were produced via the lost wax technique. The dentin blocks and their respective ceramic blocks were cemented with a self-adhesive resin cement (RelyX U200, 3M ESPE), and cement excess was removed from the margin using four different techniques, followed or not by polishing with silicone rubber tips: MBr, removal with microbrush and photoactivation; MBr-Pol, MBr + polishing; Br, removal with brush and photoactivation; Br-Pol, Br + polishing; Photo-Expl, 5 seconds of initial photoactivation, removal with explorer, and final curing; Photo-Expl-Pol, Photo-Expl + polishing; Photo-SB, 5 seconds of initial photoactivation, removal with scalpel, and final curing; and Photo-SB-Pol, Photo-SB + polishing. After 24 hours, the roughness in the marginal region was analyzed using a profilometer (three measurements on each sample). Micromorphological analyses of the region were performed by stereomicroscope and scanning electron microscopy (SEM). Then the samples were contaminated with sucrose broth standardized suspension with Streptococcus mutans, Staphylococcus aureus, and Candida albicans and incubated for a period of 48 hours. The samples were quantitatively analyzed for bacterial adherence in the marginal region by confocal laser scanning microscopy and counting of colony-forming units (CFUs/mL) and qualitatively analyzed using SEM. Roughness data (Ra) were submitted to two-way analysis of variance, Tukey test at a confidence level of 95%, and Student t-tests. CFU, biomass, and biothickness data were analyzed by Kruskal-Wallis, Mann-Whitney, and Dunn tests. The removing technique statistically influenced Ra (MBr, p=0.0019; Br, p=0.002; Photo-Expl, p=0.0262; Photo-SB, p=0.0196) when comparing the polished and unpolished groups. The MBr and MBr-Pol technique differed significantly for CFU/mL values (p=0.010). There was no significant difference in the amounts of biomass and biothickness comparing polished and unpolished groups and when all groups were compared (p>0.05). Different morphological patterns were observed (more regular surface for polished groups). We conclude that margin polishing after cementation of feldspar/pressed ceramic restorations is decisive for achieving smoother surfaces, as the excess cement around the edges can increase the surface roughness in these areas, influencing bacterial adhesion.

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