Significant Difference In Surface Roughness Research Articles

The effects of different irrigation agents on root canal dentine micro-hardness and surface roughness

Aim: Successful endodontic treatments rely on sufficient mechanical preparation and irrigation of the root canal followed by an adequate three-dimensional filling. This study investigated the changes in root dentine micro-hardness and surface roughness upon treatment with different irrigating agents.
 Methodology: A total of 60 human maxillary incisors and canine teeth were used in this study. The crowns of all teeth were decoronated and roots were divided longitudinally. The samples were separated into three groups prior to irrigation. A 5% NaOCl irrigation agent was applied to the first group, a QMix agent was used for the second group, and a 2% CHX agent was used for the third group. All irrigations were performed for 15 minutes. Following irrigation, microstructural and surface-roughness measurements were taken again from all samples.
 Results: Micro-hardness was not significantly different between QMix or 5% NaOCl (p>0.05). A significant difference was observed between the QMix- and 2% CHX-treated groups, and between the 5% NaOCl- and QMix-treated groups (p<0.05). A significant difference in surface roughness was observed between the QMix and 2% CHX, and between the 5% NaOCl and QMix (p<0.05). No difference in surface roughness was observed between 5% NaOCl or 2% CHX. The 5% NaOCl and QMix agents reduced the dentine micro-hardness equal to or more than that of the 2% CHX agent. The QMix agent also increased the dentine surface roughness significantly more than the other agents. The 5% NaOCl and 2% CHX agents increased surface roughness equally.
 Conclusions: It was seen that all of the irrigation agents used in our study affected dentin microhardness and surface roughness at different rates.
 
 How to cite this article: Öztekin F, Adıgüzel Ö. The effects of different irrigation agents on root canal dentine micro-hardness and surface roughness. Int Dent Res 2019;9(1):16-21.
 
 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Active gelatin films incorporated with eugenol nanoemulsions: effect of emulsifier type on films properties

SummaryThe objective of this work was to study the impacts of the addition of eugenol nanoemulsions (NE) stabilised with two natural emulsifiers, soy lecithin (SL) or sodium caseinate (NaCas), on the properties of gelatin films for active packaging. All the films added with NE displayed higher tensile strength and elongation at break than control films. Films added with NaCas‐stabilised NE were more resistant to tension compared to films added with SL‐stabilised NE. Gelatin films added with both NE, showed significant differences in surface roughness compared to control film. Fourier‐transform infrared spectra showed that both NE achieved complete miscibility within the films. Differential scanning calorimetry analyses suggested compatibility among both NE embedded into the films. These films indicated great antioxidant activities monitored via ABTS radical scavenging activities. These findings are essential to better design active films incorporated with nanoemulsions, in order to optimise film formulation rationally towards their eventual application as food packaging.

Evaluation of Nanomechanical Properties, Surface Roughness, and Color Stability of Esthetic Nickel-Titanium Orthodontic Archwires.

Objectives:The objective of the study is to evaluate the surface roughness, nanomechancial properties the color stability of three brands of coated (rhodium, epoxy, and Teflon) nickel-titanium (NiTi) esthetic archwires.Materials and Methods:Three brands of coated (rhodium, epoxy, and Teflon) esthetic NiTi archwires and three brands of uncoated (NiTi) archwires from the same manufactures were evaluated for the surface roughness, nanomechanical properties, and color stability. The specimens with 20 mm length (n = 5) were cut from the straight buccal segments of the coated and uncoated archwires. The specimens with 20 mm length (n = 10) were subjected to color measurement after immersion in a coffee staining solution. The color measurement was evaluated after 7, 14, 21, and 28 days after immersion in staining solution using color eye 7000 spectrophotometer. The experimental data were analyzed using descriptive statistics, analyses of variance, and Tukey's post hoc test.Results:Epoxy (1.517 ± 0.071) and rhodium (0.297 ± 0.015) coated archwires showed the highest and lower value of surface roughness. All the intergroup comparisons showed a significant difference (P < 0.05) in surface roughness except between rhodium and control group (P = 0.998). There were significant differences between control and the experimental groups for both nanohardness and elastic modulus was observed. All the three NiTi-coated esthetic archwires demonstrated trace” (extremely slight change) color changes as measured by the National Bureau of Standards units after 4 weeks of immersion.Conclusion:Surface roughness of rhodium-coated archwires was almost similar to that of uncoated wires. Whereas Teflon and epoxy coated archwires showed a significant difference in surface roughness compared to uncoated archwires. Uncoated archwires showed higher nanohardness values compared to the coated archwires. Teflon-coated archwires demonstrated significantly slight color change after 4 weeks of immersion in staining solution.

Evaluation of colour change and surface roughness of two resin-based composites when exposed to beverages commonly used by children: an in-vitro study

AimTo evaluate and compare the surface roughness and colour change of microhybrid and nanocomposite after exposure to beverages commonly used by children.MethodsThirty discs were prepared using Filtek Z250 and Filtek Supreme composites. Discs were immersed in distilled water, orange juice and Coca-Cola. Colour and surface roughness were measured at baseline and on days 15 and 30.ResultsFiltek Z250 and Filtek Supreme showed no significant difference in surface roughness and colour change at all measurement times. Immersion solution had a significant effect on surface roughness as well as colour change. Specimens immersed in Coca-Cola demonstrated the highest effect, followed by those immersed in orange juice, while specimens immersed in distilled water had the least effect. There was a significant increase in surface roughness and colour change over time. The change in colour was more evident in the period between baseline measurements and after 15 days. There was a significant interaction between media type and time.ConclusionsBoth composites showed no significant difference in roughness and colour change at all measurement times. There was a significant increase in surface roughness and colour change in all immersion solutions tested over time. Coca-Cola caused unacceptable colour change.

Tribological performances of total knee prostheses: Roughness measurements on medial and lateral compartments of retrieved femoral components

BackgroundTotal replacement of the knee joint is a well-established surgical procedure performed to relieve pain and to restore the functionality of a compromised knee. Nevertheless, wear is still one of the main issues affecting joint prostheses, causing loosening and, eventually, implants failure. Surface roughness of the implant has been found to influence the mechanisms for premature wear, having relevant influence on the tribological performance. QuestionJoint load distribution have provided valuable insight into the knee loading patterns, showing that joint contact loads differ in medial and lateral condyles. We wondered if it is possible to find any alteration between surface roughness of medial and lateral sides and if the body mass index is in any way related to the in vivo roughening of the elements. MethodsFor this purpose, 11 explants of total knee replacement (mean follow up of 3.2 years), with identical design, were analysed acquiring the roughness on the femoral components. ResultsMacroscopic inspections show that lateral condyles underwent more surface damage than the medial ones. However, surface roughness was not significantly different comparing medial and lateral sides. Statistical tests outlined a significant difference in surface roughness when distinct sizes of implants, namely 3 and 4, are considered.

The quantification of surface roughness on root caries using Noncontact Optical Profilometry\u2014An in vitro study

PurposeThe aim of this study was to quantify surface roughness of carious dentine using noncontact optical profilometry (NCOP) in vitro.MethodsA total of 20 extracted teeth with root caries were examined according to clinical assessment criteria. NCOP (Proscan 2000, Scantron, Taunton, UK) was used to carry out the surface roughness measurements in vitro. Selection of sampling rate measurements were subsequently performed.ResultsResults showed that the surface roughness (Ra) values were most accurately obtained at a sampling rate of 30 Hz. All lesions had rough texture, with cavitation ranging from 0.5 to 4 mm. Most lesions were leathery, whilst remaining few were soft. There was a significant difference in surface roughness between the carious and sound dentine (p < 0.05). Pearson’s correlation coefficient tests failed to show any significant linear correlation between surface roughness measurements and cavitation (r 0.39; p > 0.05) whilst there was a significant correlation between the hardness and surface roughness (r 0.47, p = 0.04). There was an inverse relationship trend between surface roughness measurements and severity of root caries.ConclusionsThere are limitations due to the sophisticated layout of collage network within the root carious dentine especially cavitated lesions. The NCOP could be considered for the quantification of surface roughness on noncavitated carious dentine in a laboratory setting.Clinical significanceThe effect of different oral health care products on root caries using the NCOP without causing any potential damage to the noncavitated root surface could be assessed prior to the large-scale clinical studies.

Remineralizing Effectiveness of Calcium Sucrose Phosphate and Fluoride Dentifrices: An In vitro Study.

Context:Dentifrices-containing remineralizing agents are known to be effective in remineralization of early enamel lesions.Aims:This study aimed to compare and evaluate the changes in surface roughness, surface morphology, and mineral content of demineralized enamel lesion after treatment with dentifrices-containing sodium monofluorophosphate, amine fluoride, and Anticay® (calcium sucrose phosphate with inorganic amorphous calcium phosphate).Settings and Design:This was an in vitro study.Subjects and Methods:Eighteen extracted maxillary molars were decoronated and sectioned into four to obtain 72 specimens. Specimens were demineralized and randomly divided into four different test groups: Group A: no treatment (control), Group B: sodium monofluorophosphate dentifrice (Colgate), Group C: amine fluoride dentifrice (Amflor), Group D: Anticay® dentifrice (EnaFix) and subjected to pH-cycling for 4 weeks. After 4 weeks, they were assessed using a profilometer and scanning electron microscope (SEM)-energy dispersive X-ray analysis (EDAX) for changes in surface roughness, surface morphology, and mineral content.Statistical Analysis Used:Intergroup comparison was done using repeated measures ANOVA.Results:Intergroup comparison revealed no significant difference in surface roughness and mineral content after remineralization between the groups. SEM images showed mineral deposition in all the dentifrice groups obliterating the defects caused due to demineralization.Conclusions:Sodium monofluorophosphate, amine fluoride-containing dentifrices, and calcium sucrose phosphate with inorganic amorphous calcium phosphate-containing dentifrice were found equivocal in their remineralizing effectiveness of early enamel lesions.

Effect of conventional and microwave glazing on surface roughness of metal ceramics: An atomic force microscopy analysis.

This study investigated and compared the surface roughness achieved by glazing porcelain samples in a conventional and a microwave oven. Two commercial brands of metal ceramics were used, VITA VMK MASTER and IPS CLASSIC. Sixty samples were fabricated, 30 for each type of ceramic. The samples were sintered in the conventional oven and hand-polished to remove any irregularities. Samples (n = 10) from each type of ceramic were further divided into three groups as follows: hand-polished (Group A), conventional oven glazed (Group B), and microwave glazed (Group C). Each specimen was evaluated for surface roughness by atomic force microscope. Data were statistically analyzed using two-way analysis of variance (ANOVA) and Tukey's post hoc test (a = 0.05). Two-way ANOVA indicated a highly significant difference in surface roughness based on the type of glazing (P < 0.001), there was a significant difference based on the metal ceramics (P = 0.002). There was also a significant interaction between the type of glazing and metal ceramics (P = 0.009). The images obtained from the atomic force microscope corroborated the measured values. All the results indicate that microwave glazing can be a feasible option for glazing porcelain specimens. It was concluded that surface topography is influenced by surface treatment and microwave glazed ceramic is superior to conventional oven glazed ceramic and hand-polishing showed greater surface roughness when compared to glazing. IPS CLASSIC ceramic showed relatively smooth surface when compared to VITA VMK MASTER irrespective of the surface treatment.

ENAMEL SURFACE QUALITY IMPROVEMENT IN WHITE SPOT LESIONS AFTER ORTHODONTIC TREATMENT USING A MICROABRASION TECHNIQUE WITH FLUORIDE OR CALCIUM PHOSPHOPEPTIDE-AMORPHOUS CALCIUM PHOSPHATE APPLICATION

Objectives: White spot lesions after fixed orthodontic treatment will increase bacterial plaque formation due to increased enamel surface roughness. The aim of this study was to analyze the surface roughness of white spot lesions on enamel after a microabrasion technique, a microabrasion technique combined with calcium phosphopeptide-amorphous calcium phosphate (CPP-ACP) application, and a microabrasion technique combined with fluoride application.Methods: Artificially induced white spot lesions on the enamel surfaces of 42 maxillary first premolars were randomly assigned into one of three treatment groups (n=14): (a) A microabrasion technique, (b) a microabrasion technique combined with CPP-ACP application, and (c) a microabrasion technique combined with fluoride application. A Mitutoyo SJ-301 surface roughness tester was used to measure differences in surface roughness before and after treatment, and the after treatment measurements were compared among the three groups.Results: A significant difference in surface roughness was noted for the white spot lesions on enamel before and after treatment in all groups (p&lt;0.05). A significant difference was also found when comparing the after treatment surface roughness in all groups.Conclusion: The combination of the microabrasion technique with CPP-ACP application significantly reduced enamel surface roughness when compared to microabrasion alone or the combination of microabrasion and fluoride application.

Superhydrophilic co-polymer coatings on denture surfaces reduce Candida albicans adhesion—An in vitro study

ObjectiveIn this study, we aimed to investigate denture-base-resin coatings prepared with a crosslinkable co-polymer containing sulfobetaine methacrylamide (SBMAm) and the relationship between their surface characteristics and the initial adhesion of Candida albicans (C. albicans). MethodsAcrylic resin discs were coated with co-polymers containing various concentrations of SBMAm and N,N’-(4,7,10-trioxa-1,13-tridecadiamine) diacrylamide (JDA) as crosslinking agent. Uncoated discs were used as controls. An acquired pellicle was formed on each disc using artificial saliva, and the discs were immersed in a suspension of C. albicans (JCM2085) cells. After incubation, tetrazolium salt (XTT-reduction) and colony forming unit (CFU) assays were performed and the morphogenesis of C. albicans was examined using scanning electron microscopy (SEM). The surface roughness, film thickness, and the water contact angle of each disc surface were measured. ResultsAll coating groups showed significantly lower amounts of adhered C. albicans in the XTT-reduction and CFU assays than the control, confirmed by the SEM images. Many wrinkle structures were observed on the surfaces coated with co-polymers containing more than 30% SBMAm. There were no significant differences in surface roughness among all groups. The co-polymer films on the coated discs were less than 5.0 μm in thickness, and these surfaces exhibited significantly lower mean water contact angles than the control. ConclusionCrosslinkable co-polymers containing SBMAm can enhance the hydrophilicity of the surface of denture-base resins and reduce the initial adhesion of C. albicans.

Polishing of Monolithic Zirconia Crowns-Results of Different Dental Practitioner Groups.

This pilot study evaluates the surface roughness of monolithic zirconia crowns after chairside polishing by different dental practitioner groups. Four practitioner groups (group I: dental clinical students (n = 6); group II: dentists < 2 years post-qualification experience (n = 6); group III: dentists > 2 years post-qualification experience (n = 6) and group IV: dental technicians (n = 6)) were asked to polish two CAD/CAM-fabricated full-contour zirconia crowns (48 in total). A two-step zirconia polishing kit was used in both trials. The first trial (T1) was conducted without a time limitation. In the second trial (T2), the polish was restricted to 15 seconds for each polisher. Two blinded investigators (I1 and I2) analyzed the surface roughness (Ra) before and after polishing (Alicona measuring system). No statistically significant difference in surface roughness was found between the polishing results of the dental practitioner groups. Major difference in surface finish was achieved by dental technicians, with a median value of 25.4 nm (interquartile range 10.15–35.26 nm) for I1 in T1. The lowest difference was achieved by dental students, with a median value of Ra = 6.72 nm (interquartile range 4.7–17.9 nm) in T1. In T2, experienced dentists showed the highest difference in surface finish, with a median value of 41.35 nm (interquartile range 7.77–54.11). No significant correlation was found between polishing time and polishing results. The polishing of monolithic zirconium dioxide crowns can be performed with the present polishing set directly chairside after occlusal adjustment, regardless of the practitioner’s experience level.

Effect of Lowering Laser Energy on the Surface Roughness of Human Corneal Lenticules in SMILE.

To determine the effect of lowering femtosecond laser energy on the surface quality of the intrastromal interface during small incision lenticule extraction (SMILE). Forty age- and diopter-matched female patients (40 eyes) with moderate myopia received SMILE with different energy levels (100 to 150 nJ) and fixed spot separation (4.5 μm). Five human corneal lenticules from each energy group were evaluated by atomic force microscopy and scanning electron microscopy (SEM). Both anterior and posterior surface characteristics of the lenticules were assessed. All measurements of surface roughness were approximately three times higher and in the anterior and posterior surface of the lenticules with the energy level of 150 nJ than with 100 nJ (P < .001). Furthermore, atomic force microscopy analysis found that energy differences of 15 nJ or more made a significant difference in surface roughness at energy levels of 115 nJ or higher. Interestingly, there was no significant difference in all roughness values of both surfaces among the 100, 105, and 110 nJ groups. In addition, all values of surface roughness were significantly positively correlated with laser energy for both anterior and posterior surfaces of the lenticule (P < .001). Consistent with atomic force microscopy results, SEM also showed that the SMILE lenticules in the higher laser energy group had more irregular surfaces. Lowering laser energy levels can improve surface quality of the lenticule of SMILE. To achieve better visual outcomes with faster recovery after the procedure, it is recommended to reduce the laser energy to less than 115 nJ at a spot separation of 4.5 μm. [J Refract Surg. 2017;33(9):617-624.].

Differences in surface roughness of nanohybrid composites immersed in varying concentrations of citric acid

Background: The surface roughness of restoration is important in predicting the length of time it might remain in the mouth. Conditions within the oral cavity can affect the surface roughness of a restoration. Nanohybrid composite is widely used in dentistry because it can be applied to restore anterior and posterior teeth. Athletes routinely consume isotonic drinks which are acidic and even more erosive than the carbonated variety because they contain a range of acids; the highest content of which being citric acid. Purpose: The aim of the study was to analyze the surface roughness of nanohybrid composite after having been subjected to immersion in varying concentrations of citric acid. Methods: Two isotonic drinks (Pocari Sweat and Mizone) were analyzed using high performance liquid chromatography (HPLC) to quantify the respective concentrations of citric acid which they contained. A total of 27 samples of cylindrical nanohybrid composite were prepared before being divided into three groups. In Group 1, samples were immersed in citric acid solution derived from Pocari Sweat. Those of Group 2 were immersed in citric acid solution derived from Mizone; while Group 3, samples were immersed in distilled water as a control. All samples were immersed for 7 days, before their surface roughness was tested by means of a surface roughness tester (Mitutoyo SJ-201). Data was analyzed using a one-way ANOVA test. Results: The results showed that there was no significant difference in surface roughness between Groups 1, 2 and 3 (p=0.985). Conclusion: No difference in surface roughness of nanohybrid composites results from prolonged immersion in varying concentrations of citric acid.

Comparative Effect of Different Polymerization Techniques on the Flexural and Surface Properties of Acrylic Denture Bases.

Polymerization techniques have been modified to improve physical and mechanical properties of polymethylmethacrylate (PMMA) denture base, as have the laboratory procedures that facilitate denture construction techniques. The purpose of the present study was to investigate the effect of autoclave polymerization on flexural strength, elastic modulus, surface roughness, and the hardness of PMMA denture base resins. Major Base and Vertex Implacryl heat-polymerized acrylic resins were used to fabricate 180 specimens. According to the polymerization technique, tested groups were divided into: group I (water-bath polymerization), group II (short autoclave polymerization cycle, 60°C for 30 minutes, then 130°C for 10 minutes), and group III (long autoclave polymerization cycle, 60°C for 30 minutes, then 130°C for 20 minutes). Each group was divided into two subgroups based on the materials used. Flexural strength and elastic modulus were determined by a three-point bending test. Surface roughness and hardness were evaluated with a profilometer and Vickers hardness (VH) test, respectively. One-way ANOVA and the Tukey-Kramer multiple-comparison test were used for results analysis, which were statistically significant at p ≤ 0.05. Autoclave polymerization showed a significant increase in flexural strength and hardness of the two resins (p < 0.05). The elastic modulus showed a significant increase in the major base resin, while a significant decrease was seen for Vertex Implacryl in all groups (p < 0.05); however, there was no significant difference in surface roughness between autoclave polymerization and water-bath polymerization (p > 0.05). Autoclave polymerization significantly increased the flexural properties and hardness of PMMA denture bases, while the surface roughness was within acceptable clinical limits. For a long autoclave polymerization cycle, it could be used as an alternative to water-bath polymerization.

Streptococcus mutans forms xylitol-resistant biofilm on excess adhesive flash in novel ex-vivo orthodontic bracket model.

During orthodontic bonding procedures, excess adhesive is invariably left on the tooth surface at the interface between the bracket and the enamel junction; it is called excess adhesive flash (EAF). We comparatively evaluated the biofilm formation of Streptococcus mutans on EAF produced by 2 adhesives and examined the therapeutic efficacy of xylitol on S mutans formed on EAF. First, we investigated the biofilm formation of S mutans on 3 orthodontic bracket types: stainless steel preadjusted edgewise, ceramic preadjusted edgewise, and stainless steel self-ligating. Subsequently, tooth-colored Transbond XT (3M Unitek, Monrovia, Calif) and green Grengloo (Ormco, Glendora, Calif) adhesives were used for bonding ceramic brackets to extracted teeth. S mutans biofilms on EAF produced by the adhesives were studied using the crystal violet assay and scanning electron microscopy. Surface roughness and surface energy of the EAF were examined. The therapeutic efficacies of different concentrations of xylitol were tested on S mutans biofilms. Significantly higher biofilms were formed on the ceramic preadjusted edgewise brackets (P=0.003). Transbond XT had significantly higher S mutans biofilms compared with Grengloo surfaces (P=0.007). There was no significant difference in surface roughness between Transbond XT and Grengloo surfaces (P>0.05). Surface energy of Transbond XT had a considerably smaller contact angle than did Grengloo, suggesting that Transbond XT is a more hydrophilic material. Xylitol at low concentrations had no significant effect on the reduction of S mutans biofilms on orthodontic adhesives (P=0.016). Transbond XT orthodontic adhesive resulted in more S mutans biofilm compared with Grengloo adhesive on ceramic brackets. Surface energy seemedto play a more important role than surface roughness for the formation of S mutans biofilm on EAF. Xylitol does not appear to have a therapeutic effect on mature S mutans biofilm.

KEKASARAN PERMUKAAN RESIN KOMPOSIT NANOFILLER SETELAH PERENDAMAN ALAM AIR SUNGAI DAN AIR PDAM

ABSTRACT Background :One of composite resin kinds is often used for tooth restoration, it is nanofilled composite resin. Nanofilled composite resin is a restoration material containing nano size filler particle, so that it can repair the physical characteristic of composite such as reducing the surface roughness. People in Barito Kuala especially in Desa Anjir Pasar, besides using tap water, they also still use water from river for daily use. The water of river in Desa Anjir Pasar has acid characteristic with Ph range 3-5. An acidic environment causes surface roughness of nanofilled composite resin which allow the secunder caries.Purpose : The aim of this research was to know the difference in surface roughness of nanofilled composite resin after being immersed in river water, tap water, and sterile aquades. Method :This research was a true experimental research with post test only and control group design, used nanofilled composite resin disc samples with diameter of 10 mm and 2 mm thick divided into 3 groups of treatment. Each group was immersed in sterile aquades (as control group), tap water, and river water with acid Ph for 8 days (equals to 3 years of exposure), then the surface roughness was measured using surface roughness measurement. Result : Data was tested using parametric analysis one way anova 95% ( = 0,05) and it obtained p = 0,000 (p = < 0,05). Based on the result it can be concluded that there was significant difference in surface roughness on nanofilled composite resin which had been immersed in each water sample for 8 days. Conclusion : Nanofilled resin composite immersed in river water had higher mean value of surface roughness compared to immersion in sterile aquades and tap water. Keywords: Resin Nanofilled Composite, River Water, Tap Water, Surface Roughness

Effect of Anti-Erosion Toothpastes on Surface Roughness of Different Restorative Materials

Purpose: The aim of this study was to evaluate the effects of three anti-erosion toothpastes (Sensodyne Proenamel, Biorepair, and Regenerate) on surface roughness (Sa) of three tooth-colored restorative materials: Resin composite (RC), glass ionomer cement (GI), and resin-modified glass-ionomer cement (RMGI). Methods: Sixty cylindrical specimens were prepared from each material and then were finished and polished and the first surface roughness (Sa) readings (T1) were recorded. Each material was randomly divided into 4 groups according to the antierosion toothpastes or water as control. Then application of the anti-erosion toothpastes or water for one hour for each group. Brushing was performed manually using electric toothbrush for one hour which is equivalent to brushing for two minutes twice each day for 15 days and then surface roughness (T2) of each specimen was recorded using a 3D noncontact profilometer. Result: Comparing the effect of anti-erosion toothpastes on the three restorative materials using ANOVA showed a statistically significant in the Filtek Z250 XT groups (p=0.006) but not in GC Fuji II LC groups (p=0.444) nor Ketac Fil Plus Aplicap groups (p=0.166). The highest Sa (Mean±SD) at T1 was observed in Ketac Fil Plus Aplicap (0.73±0.45) followed by GC Fuji II LC (0.32±0.09) then Filtek Z250 XT (0.16±0.02). For Filtek Z250 XT, there was statistically significant difference in surface roughness between distilled water and Sensodyne Pronamel (p=0.005) and between Sensodyne Pronamel and Regenerate (p=0.036). There was no statistically significant difference in surface roughness between different surface treatments for GC Fuji II LC (p=0.942) and Ketac Fil Plus Aplicap (p=0.447). Conclusion: Brushing tested restorative materials with anti-erosion toothpastes resulted in significant changes on their surface roughness and the most toothpaste caused change on Filtek Z250 XT was Sensodyne Pronamel, for the GC Fuji II LC was Biorepair, and for and Ketac Fil Plus Aplicap was Regenerate. Surface roughness varied depending on the anti-erosion toothpastes and the restorative material used.

Effect of polishing method on surface roughness and bacterial adhesion of zirconia-porcelain veneer

The purpose of this study was to evaluate the effect of various polishing methods on surface roughness of zirconia-porcelain veneer and to correlate the findings with early bacterial adhesion. The study specimens were glazed (control group), glazed after fine polishing (glazed group) and polished with Exa Cerapol (Cerapol group) or with Shofu porcelain adjustment kit (Shofu group) (n =20). Surface roughness was then measured using profilometer and scanning electron microscope (SEM). After artificial saliva coating, the specimens were incubated in Streptococcus mitis suspension for 4h at 37°C. Adherent bacteria were quantified from SEM images. Streptococcal viability was assessed by LIVE/DEAD staining kit and fluorescent microscope. There were significant differences in surface roughness according to polishing method and surface material. Relatively smoother surfaces were found in zirconia surfaces and glazed porcelain surfaces. There were also significant differences in bacterial adhesion according to polishing method and surface material. Cerapol group showed minimal bacterial adhesion with more dead cells when compared to other groups. A positive correlation between surface roughness and bacterial adhesion was found in glazed porcelain surface and a negative correlation in zirconia surface of Cerapol group, both with no statistical significance. Within the limitations of in vitro study, surface roughness and bacteria adhesion were significantly influenced by polishing method and surface material. Also, there was a positive correlation and negative correlation between surface roughness and bacterial adhesion in glazed porcelain surface and in zirconia surface of Cerapol group, respectively.

Experimental study on quality of PCD tools machined by different electric discharge grinding processes

AbstractPolycrystalline diamond (PCD) is a promising tool material which is utilized to cut difficult-to-machine materials used in aerospace industry. Because of its ultra-hardness, electrical discharge grinding (EDG), a variation of electrical discharge machining, is often adopted to manufacture PCD tools to reduce manufacturing time. This paper investigates the quality of PCD inserts manufactured by two different EDG eroding methods: “2-step machining” and “3-step machining”. Surface roughness and residual stress were investigated after EDG process. An orthogonal cutting experiment was conducted to test the performance of each PCD insert. PCD tools machined with the two methods do not have significant difference in surface roughness. The residual stress status changed from compressive to tensile after EDG process. Also, after being eroded by 3-step EDG process, there was an over 30% declination of residual stress compared with 2-step machining. The results of the orthogonal cutting test showed that the ...

Effect of Mouth Rinses on Surface Roughness of Two Methacrylate-Based and Siloraine-Based Composite Resins

Background: Various fluids in the oral environment can affect the surface roughness of resin composites. This in vitro study was conducted to determine the influence of the mouth rinses on surface roughness of two methacrylate-based resin (nanofilled and packable composite) and siloraine-based resin composites. Materials and methods : Disc-sh aped specimens (12 mm in diameter and 2mm in height) were prepared from three types of composite resin materials: Filtek™ Z350 XT, Filtek™ P60 and Filtek™ P90.Thirty specimens were prepared from each composite type and subdivided into three subgroups (n=10 ) according to the type of treatment solution: distilled water (control), Listerine (alcohol-containing), Sensodyne Pronamel (alcohol free fluoride- containing). Each subgroup was immersed in 20 ml of treatment solutions and incubated at 37°C for 24 hr and then subjected to surface roughness test by profilometer .The resulting data were statistically analyzed using ANOVA and LSD test at0.05 significance level. Results : The results of this study showed that both mouth rinses irrespective of the presence or absence of alcohol resulted in significant increase in the surface roughness of the tested resin composite materials compared to control with no significant difference between the two mouth rinses. Comparison among the three types of resin in each treatment solution showed that there was a statistically high significant difference in surface roughness between all subgroups Conclusion : Both alcohol-containing and alcohol-free fluoride containing mouth rinses cause highly significant increase in surface roughness of composite resins. Composite changes depended on the material itself rather than the mouth rinse solution used. Key word s : Composite resin, mouth rinses, siloraine, surfaces roughness.