PURPOSE: Surface finishing of a zirconia restoration is essential after clinical adjustment. Herein, we investigated the effects of a surface finishing protocol for monolithic zirconia on final roughness and bacterial adherence. MATERIALS AND METHODS: Forty-eight disk-shaped monolithic zirconia specimens were fabricated and divided into four groups (n = 12) based on initial surface treatment, finishing, and polishing protocols: diamond bur+polishing bur (DP group), diamond bur+stone grinding bur+polishing bur (DSP group), no diamond bur+polishing bur (NP group), and no diamond bur+stone grinding bur+polishing bur (NSP group). Initial and final surface roughness was measured with a profilometer, and shown using scanning electron microscope. Bacterial adhesion was evaluated by quantifying Streptococcus mutans in the biofilm. Kruskal-Wallis and Mann-Whitney U tests were used to compare results among groups, and two-way analysis of variance was used to evaluate the effects of grinding burs on final roughness (α=.05). RESULTS: The DP group had the highest final Ra value, followed by the DSP, NP, and NSP groups. Use of the stone grinding bur as a coarse-finishing step significantly decreased final Ra values when a diamond bur was used (P < .001). Omission of the stone grinding bur increased biofilm formation on specimen surfaces. Combining a stone grinding bur with silicone polishing burs produced the smallest final biofilm values, regardless of the use of a diamond bur in initial surface treatment. CONCLUSION: Coarse finishing of monolithic zirconia with a stone grinding bur significantly decreased final Ra values and bacterial biofilm formation when surfaces had been roughened by a diamond bur.
Bacterial Adhesion ; Biofilms ; Dental Instruments ; Dental Polishing ; Diamond ; Silicon ; Silicones ; Streptococcus mutans

PURPOSE: The aim of this study was to compare the effect of different finishing and polishing techniques on water absorption, water solubility, and microhardness of ceramic or glass-polymer based computer-aided design and computer-aided manufacturing (CAD/CAM) materials following thermocycling. MATERIALS AND METHODS: 150 disc-shaped specimens were prepared from three different hybrid materials and divided into five subgroups according to the applied surface polishing techniques. All specimens were subjected up to #4000 grit SiC paper grinding. No additional polishing has been done to the control group (Group I). Other polishing procedures were as follows: Group II: two-stage diamond impregnated polishing discs; Group III: yellow colored rubber based silicone discs; Group IV: diamond polishing paste; and Group V: Aluminum oxide polishing discs. Subsequently, 5000-cycles of thermocycling were applied. The analyses were conducted after 24 hours, 7 days, and 30 days of water immersion. Water absorption and water solubility results were analyzed by two-way ANOVA and Tukey post-hoc tests. Besides, microhardness data were compared by Kruskal-Wallis and Mann-Whitney U tests (P<.05). RESULTS: Surface polishing procedures had significant effects on water absorption and solubility and surface microhardness of resin ceramics (P<.05). Group IV exhibited the lowest water absorption and the highest microhardness values (P<.05). Immersion periods had no effect on the microhardness of hybrid ceramic materials (P>.05). CONCLUSION: Surface finishing and polishing procedures might negatively affect physical properties of hybrid ceramic materials. Nevertheless, immersion periods do not affect the microhardness of the materials. Final polishing by using diamond polishing paste can be recommended for all CAD/CAM materials.
Absorption ; Aluminum Oxide ; Ceramics ; Computer-Aided Design ; Dental Polishing ; Diamond ; Immersion ; Rubber ; Silicon ; Silicones ; Solubility ; Water

PURPOSE: The purpose of this study was to evaluate the effects of various protocols and systems for finishing and polishing monolithic zirconia on surface topography, phase transformation, and bacterial adhesion. MATERIALS AND METHODS: Three hundred monolithic zirconia specimens were fabricated and then treated with three finishing and polishing systems (Jota [JO], Meisinger [ME], and Edenta [ED]) using four surface treatment protocols: coarse finishing alone (C); coarse finishing and medium polishing (CM); coarse finishing and fine polishing (CF); and coarse finishing, medium polishing, and fine polishing (CMF). Surface roughness, crystal phase transformation, and bacterial adhesion were evaluated using atomic force microscopy, X-ray diffraction, and streptococcal biofilm formation assay, respectively. One-way and two-way analysis of variance with Tukey post hoc tests were used to analyze the results (α=.05). RESULTS: In this study, the surface treatment protocols and systems had significant effects on the resulting roughness. The CMF protocol produced the lowest roughness values, followed by CM and CF. Use of the JO system produced the lowest roughness values and the smallest biofilm mass, while the ME system produced the smallest partial transformation ratio. The ED group exhibited the highest roughness values, biofilm mass, and partial transformation ratio. CONCLUSION: Stepwise surface treatment of monolithic zirconia, combined with careful polishing system selection, is essential to obtaining optimal microstructural and biological surface results.
Bacterial Adhesion ; Biofilms ; Clinical Protocols ; Dental Polishing ; Microscopy, Atomic Force ; X-Ray Diffraction

OBJECTIVES: The aim of this in vitro study was to test the effect of 2 finishing–polishing sequences (QB, combining a 12/15-fluted finishing bur and an EVO-Light polisher; QWB, adding a 30-fluted polishing bur after the 12/15-fluted finishing bur used in the QB sequence) on 5 nanotech-based resin composites (Filtek Z500, Ceram X Mono, Ceram X Duo, Tetric Evoceram, and Tetric Evoceram Bulk Fill) by comparing their final surface roughness and hardness values to those of a Mylar strip control group (MS). MATERIALS AND METHODS: Twelve specimens of each nanocomposite were prepared in Teflon moulds. The surface of each resin composite was finished with QB (5 samples), QWB (5 samples), or MS (2 samples), and then evaluated (60 samples). Roughness was analysed with an optical profilometer, microhardness was tested with a Vickers indenter, and the surfaces were examined by optical and scanning electron microscopy. Data were analysed using the Kruskal-Wallis test (p < 0.05) followed by the Dunn test. RESULTS: For the hardness and roughness of nanocomposite resin, the QWB sequence was significantly more effective than QB (p < 0.05). The Filtek Z500 showed significantly harder surfaces regardless of the finishing–polishing sequence (p < 0.05). CONCLUSIONS: QWB yielded the best values of surface roughness and hardness. The hardness and roughness of the 5 nanocomposites presented less significant differences when QWB was used.
Composite Resins ; Dental Polishing ; Hardness ; In Vitro Techniques ; Microscopy, Electron, Scanning ; Nanocomposites ; Polytetrafluoroethylene

OBJECTIVEThis study aimed to compare the polishing performance of five different glass-ceramic polishing tools on CEREC Blocs ceramic and provide evidence for clinical polishing tool selection.

METHODSSixty ceramic specimens were prepared and divided into six groups (n=10). These specimens received different surface treatments, including glazing (group G), polishing with Shofu polishing set, that is, Porcelain Adjustment Kit+CeraMaster (group SF), 3M Sof-LexTM Discs (group 3M), TobooM polishing set (group Tob), EVE DIAPRO system (group EVE), and Ivoclar Vivadent OptraFine® system (group Ivo). Polishing quality was measured with a profilometer, and we selected Ra and Rz values for statistical analysis. Qualitative surface evaluation was performed by a scanning electron microscope (SEM).

RESULTSThe mean Ra values of each group were as follows: G (0.069 µm±0.008 µm)<3M (0.073 µm±0.009 µm)0.05), and SF and Ivo groups (P>0.05), but the remaining treatment groups were significantly different from each other (P<0.05). Statistical results of Rz values were the same as the Ra values, and visual analysis of the images obtained from SEM was consistent with the statistical results.

CONCLUSIONSThe polishing performance of different polishing tools for CEREC Blocs ceramic was different. Sof-LexTM Discs achieved the most remarkable performance, which was comparable to that of glazing. 
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Acrylic Resins ; Ceramics ; Composite Resins ; Dental Polishing ; Dental Porcelain ; Humans ; Materials Testing ; Microscopy, Electron, Scanning ; Polyurethanes ; Surface Properties

PURPOSE: The purpose of this study was to evaluate the transmission of candida in denture by dental polishing lathe. MATERIALS AND METHODS: Maxillary complete dentures made from the same model were infected with Candida albicans. Polishing wheels were keep in various chlorhexidine solution and distilled water for an hour. The infected dentures were polished by prepared dental polishing lathe with sterile pumice and distilled water. And then sterile maxillary complete dentures were polished with same method. Polishing surface was wiped with a cotton swab and the sample was regrown for checking Candida albicans. RESULTS: All polishing wheel with chlorhexidine resist fungal infection. But the polishing wheel with distilled water is infected with Candida albicans. CONCLUSION: A chlorhexidine is highly efficient in fungal infection prevention on dental polishing lathe.
Candida albicans* ; Candida* ; Chlorhexidine* ; Dental Polishing* ; Denture, Complete ; Dentures ; Methods ; Water

OBJECTIVETo investigate the effect of different surface treatment of zirconia and to find the best way to reduce the wear of its antagonist.

METHODSTwenty-five plates(5 mm×10 mm×15 mm) made of zirconia were divided into five equal groups. Group A was only ground, group B was ground and polished, group C was ground and polished then polished by prophylaxis paste, group D was ground and glazed, group E was ground, polishsed, and then reglazed. Five central incisors were embedded in autopolymerizing acrylic resin with a size of 5 mm×10 mm×15 mm as the control group F. Thirty upper premolars buccal cusps were prepared as the antagonist. Cusps were embedded in autopolymerizing acrylic resin with a shape of circular column whose diameter were 3.1 mm. The wear test was performed in the universal micro-tribotester in artificial saliva. The roughness of each group was measured with rough meter before the wear test. The volume loss of the antagonist was measured using a 3D scanner. The wear surface was observed with scanning electron microscopy to determine the wear characteristics. Data were analyzed using one-way analysis of variance.

RESULTSEach group of surface roughness and mass loss of antagonist showed significant statistical difference (P<0.05). Antagonist of group D showed the maximum volume loss([0.905±0.018] mm3). Antagonist of control group showed the least volume loss([0.235±0.017] mm3). Antagonist of group C showed less volume loss than antagonist of control group did([0.413±0.017] mm3). Wear type of enamel of control group and the antagonist of the groups in which the samples were polished with prophylaxis paste was fatigue wear, and the other groups showed abrasive and adhesive wear.

CONCLUSIONSIn the surface treatment methods of zirconia, polishing is better than glazing. Ground and polishing and then polishing with prophylaxis paste can decrease the wear of the antagonist.

Bicuspid ; Dental Enamel ; Dental Polishing ; Humans ; Materials Testing ; Microscopy, Electron, Scanning ; Surface Properties ; Tooth Crown ; Tooth Wear ; Zirconium

OBJECTIVETo evaluate the influence of different polishing methods on marginal microleakage of zirconium dioxide full crown.

METHODSThirty extracted premolars were selected and randomly divided into three groups, A, B and C, with 10 in each group. Group A was prepared with MANI TF-13 bur completely without the treatment of shoulder. The shoulder of group B was polished with MANI TR13-EF bur after the preparation using MANI TF-13. The shoulder of group C was polished with the dental pneumatic ultrasonic hand-piece of KaVo SONICflex after the preparation using MANI TF-13 bur. Five specimens after preparation were selected in each group. Fifteen CAD/CAM zirconium dioxide full crowns have been made. The crowns were bonded using PULPDENT resin cement, and the root canals were sealed using nail polish, and apical foramen were closed using flow resin. The test-pieces have been immersed in a 3% solution of methylene blue for 24 h. The condition of shoulder marginal microleakage was observed using light stereomicroscopy and evaluated in classification index. The remaining specimens in each group were used for roughness test and scanning electron microscope(SEM) experiment. The marginal microleakage situations of specimens in three groups was analyzed by SPSS 17.0. The enamel surface of different polishing methods was observed using SEM.

RESULTSThe specimens in group C demonstrated the least marginal microleakage, and those in group B showed an intermediate level of marginal microleakage, and those in group A characterized the most serious marginal microleakage (total, χ2=44.610, P<0.01; among the different groups, P<0.05). The roughness experiment showed that specimens in group C achieve the smoothest results ([0.27±0.03] μm). Preparation shoulder polished using the dental pneumatic ultrasonic hand-piece demonstrated the best result under the SEM among the three groups.

CONCLUSIONSThe anti-microleakage effectiveness of dental pneumatic ultrasonic hand-piece in shoulder refinement is better than ordinary shoulder treatment.

Bicuspid ; Computer-Aided Design ; Crowns ; Dental Enamel ; Dental Instruments ; Dental Leakage ; diagnosis ; prevention & control ; Dental Polishing ; methods ; Dental Prosthesis Design ; methods ; Humans ; Pit and Fissure Sealants ; Random Allocation ; Resin Cements ; Ultrasonics ; Zirconium

The purpose of the present study was to examine dental hygienists' perception of the current national practical examination. This research was performed using 199 self-reported surveys answered by professors of dental hygiene studies and clinical dental hygienist. Frequency analysis, chi-square tests, and analysis of variance were performed by using IBM SPSS Statistics ver. 20.0. The results revealed that many of the respondents consider the current national practical examination to be neutral. They did not think that the current national practical examination questions are useful for assessing occupation-centric integrated clinical practice ability and counseling techniques for patient intervention. The professors of dental hygiene studies believed that among the research tasks required as mentioned in the national practical examination questions, dental polishing and tooth brushing education are of paramount importance, whereas clinical dental hygienists believed that ultrasonic scaling is the most important (p<0.05). Most of the professors of dental hygiene studies reported that they conducted skills education for dental polishing and tooth brushing education, while most of the clinical dental hygienists reported that tasks actually performed in the clinic included impression taking, model fabrication, ultrasonic scaling, and explaining treatment precautions (p<0.05). Therefore, these tasks can be effectively carried out with the improvement of the national dental hygienist practical examination.
Counseling ; Dental Hygienists ; Dental Polishing ; Education ; Humans ; Oral Hygiene ; Surveys and Questionnaires ; Tooth ; Ultrasonics

Sub-gingival anaerobic pathogens can colonize an implant surface to compromise osseointegration of dental implants once the soft tissue seal around the neck of an implant is broken. In vitro evaluations of implant materials are usually done in monoculture studies involving either tissue integration or bacterial colonization. Co-culture models, in which tissue cells and bacteria battle simultaneously for estate on an implant surface, have been demonstrated to provide a better in vitro mimic of the clinical situation. Here we aim to compare the surface coverage by U2OS osteoblasts cells prior to and after challenge by two anaerobic sub-gingival pathogens in a co-culture model on differently modified titanium (Ti), titanium-zirconium (TiZr) alloys and zirconia surfaces. Monoculture studies with either U2OS osteoblasts or bacteria were also carried out and indicated significant differences in biofilm formation between the implant materials, but interactions with U2OS osteoblasts were favourable on all materials. Adhering U2OS osteoblasts cells, however, were significantly more displaced from differently modified Ti surfaces by challenging sub-gingival pathogens than from TiZr alloys and zirconia variants. Combined with previous work employing a co-culture model consisting of human gingival fibroblasts and supra-gingival oral bacteria, results point to a different material selection to stimulate the formation of a soft tissue seal as compared to preservation of osseointegration under the unsterile conditions of the oral cavity.
Acid Etching, Dental ; methods ; Alloys ; chemistry ; Bacterial Adhesion ; physiology ; Bacteriological Techniques ; Biofilms ; Cell Adhesion ; physiology ; Cell Culture Techniques ; Cell Line, Tumor ; Cell Movement ; physiology ; Ceramics ; chemistry ; Coculture Techniques ; Dental Alloys ; chemistry ; Dental Etching ; methods ; Dental Implants ; microbiology ; Dental Materials ; chemistry ; Dental Polishing ; methods ; Humans ; Osseointegration ; physiology ; Osteoblasts ; physiology ; Porphyromonas gingivalis ; physiology ; Prevotella intermedia ; physiology ; Surface Properties ; Titanium ; chemistry ; Yttrium ; chemistry ; Zirconium ; chemistry