Diamond Bur Research Articles

In-vitro polishing of CAD/CAM ceramic restorations: An evaluation with SEM and confocal profilometry

AimThe objective of this In-vitro investigation was to analyze and compare the surface after polishing of 63 all-ceramic restorations fabricated out of monolithic zirconium dioxide (ZIR), lithium disilicate (LS) or feldspathic ceramic (FC) under standardized laboratory conditions with different protocols. The primary outcome was defined as the roughness (Ra/Sa) of different ceramic surfaces after distinctive polishing procedures. Material and methodsThe study set-up consisted of three main groups: ZIR, LS, FC (20 crowns each), every group divided into two sub-groups (10 crowns each) depending on the polishing method. The untouched glazed surface of one crown per material served as a control. Every crown displayed a defined supra-contact at the palatal cusp which was removed with a fine grain (38–45 μm) diamond bur. Surface polishing was carried out with either a two-step system (one kit for zirconium dioxide (ZIR2), another kit for lithium disilicate (LS2) and feldspatic ceramic (FC2)), or a three-step system (ZIR3, LS3, FC3) under standardized conditions. Roughness parameters (Ra and Sa) were measured by means of confocal profilometry. Specimens were also visually inspected with scanning electron microscopy (SEM). Statistical analyses were performed using SPSS Statistics software. ResultsVisual examination of the specimens using SEM showed several inhomogeneities on the glazed surface of the control samples, i.e. pores and particles. On every test sample, the grinding curves of the diamond bur were still recognizable. Polishing revealed similar median Ra 0.491 μm (ZIR2) and 0.434 μm (LS2) after two-step polishing (p = 0.754), and 0.311 μm (ZIR3) and 0.208 μm (LS3) after three-step polishing (p = 0.917). Surface roughness in group FC measured 0.889 μm (FC2) after the two-step polishing process and 0.903 μm (FC3) following three-step surface refinement. No significant difference was detectable between surface roughness of glazed controls compared to either polished surfaces with two-step or three-step treatment within one material. ZIR and LS presented significantly lower median roughness Ra after two-step and three-step procedures than test samples of FC, measured subsequent to either of the polishing methods (p = 0.016, p = 0.009). ConclusionThe surface roughness of ZIR, LS and FC crowns after the use of chairside polishing kits was comparable with the roughness measured before occlusal adjustment. A two-step procedure showed as good results as a three-step process. A smoother surface was obtained for ZIR and LS compared to FC with both polishing protocols.

V06-09 USEFULNESS OF HIGH-SPEED SURGICAL AIR DRILL IN PARTIAL PUBECTOMY DURING DELAYED ANASTOMOTIC URETHROPLASTY FOR PELVIC FRACTURE URETHRAL INJURY

You have accessJournal of UrologyLower-Tract Reconstruction I: Sling/ Sphincter/ Penile & Urethral Reconstruction (V06)1 Apr 2020V06-09 USEFULNESS OF HIGH-SPEED SURGICAL AIR DRILL IN PARTIAL PUBECTOMY DURING DELAYED ANASTOMOTIC URETHROPLASTY FOR PELVIC FRACTURE URETHRAL INJURY Akio Horiguchi*, Kenichiro Ojima, Masayuki Shinchi, Yusuke Hirano, Koetsu Hamamoto, Keiichi Lto, Tomohiko Asano, and Ryuichi Azuma Akio Horiguchi*Akio Horiguchi* More articles by this author , Kenichiro OjimaKenichiro Ojima More articles by this author , Masayuki ShinchiMasayuki Shinchi More articles by this author , Yusuke HiranoYusuke Hirano More articles by this author , Koetsu HamamotoKoetsu Hamamoto More articles by this author , Keiichi LtoKeiichi Lto More articles by this author , Tomohiko AsanoTomohiko Asano More articles by this author , and Ryuichi AzumaRyuichi Azuma More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000885.09AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Partial pubectomy is an ancillary technique used in delayed anastomotic urethroplasty for pelvic fracture urethral injury (PFUI). This procedure widens the exposure of the disrupted urethra, and reduces anastomotic tension by shortening the urethral gap. Use of a less traumatic device for a pubectomy is optimal to avoid excessive bleeding from the venous plexus, located just behind the pubic symphysis. Surgical air drills enable delicate, precise bone resection and are widely used in spinal surgery. This video highlights our experience using an air drill in partial pubectomies for PFUI. METHODS: Between 2009 and 2019, 88 male patients underwent delayed anastomotic urethroplasty, with partial pubectomy for PFUI; performed by one surgeon (AH). Seventy-Three (83%) procedures used a high-speed surgical air drill (HiLAN HS®, Aesculap) equipped with a short, light hand piece. Operative time and blood loss in the air drill patient group (group 1) were compared with those patients who underwent pubectomy using rongeur and/or gouge in our early experience (group 2, n = 15, 17%). RESULTS: The median age was 37 years (IQR 23 to 55 years), the median urethral gap length on urethrogram was 25 mm (IQR 19 to 35 mm). In 65 of 73 (89%) patients, urethroplasty was performed via a perineal approach, with inferior partial pubectomy. After mobilizing the bulbar urethra and retracting split corporal bodies laterally, the inferior pubis was scraped by the drill using diamond burrs. In 8 (11%) patients whose proximal urethral end was displaced upward, superior to the upper border of pubic symphysis, urethroplasty was performed via a perineal and abdominal approach, with a superior partial pubectomy and supracrural urethral rerouting. After mobilizing the bulbar urethra via the perineal approach and making a lower abdominal incision extending over the pubic symphysis, a bony channel at the superior surface of the pubis was created by the drill. No difficulty was encountered in using the air drill in any of the cases. The surface of the pubic bone scraped by the air drill was flat; no sharp bony spikes remained. There was no significant difference in median operative time between the groups (256 minutes in group 1 vs. 228 minutes in group 2, p = 0.31). The median blood loss in group 1 (149 ml) was significantly smaller than that in group 2 (453 ml, p < 0.0001). CONCLUSIONS: Surgical air drills may be suitable for pubectomies even in amateur hands, and offer the advantage of delicate bone resection with reduced blood loss. Source of Funding: None © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e558-e558 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information Akio Horiguchi* More articles by this author Kenichiro Ojima More articles by this author Masayuki Shinchi More articles by this author Yusuke Hirano More articles by this author Koetsu Hamamoto More articles by this author Keiichi Lto More articles by this author Tomohiko Asano More articles by this author Ryuichi Azuma More articles by this author Expand All Advertisement PDF downloadLoading ...

Effect of Different Surface Treatments of Resin Relined Fiber Posts Cemented With Self-adhesive Resin Cement on Push-out and Microtensile Bond Strength Tests.

When luting relined fiber posts with self-adhesive cement, the surface treatment of the posts influences the adhesion of the fiber posts to root dentin. This study evaluated the effect of surface treatment and silanization of resin composite on the bond strength of relined fiber posts cemented with self-adhesive resin cement. Push-out and microtensile bond strength (MTBS) tests were performed in this study. The endodontic treatment of 80 single-rooted bovine teeth was first performed in the push- out test segment, followed by weakening the intracanal walls by diamond bur. Then, the glass fiber posts were adapted with resin composite to fill the root canals, followed by photoactivation and resin surface conditioning according to four different experimental conditions: no conditioning as control, 10% hydrofluoric acid, 35% hydrogen peroxide, or air abrasion with alumina particle (all groups were subdivided into "with silanization" or "without silanization," thus totaling eight experimental groups). Self-adhesive resin cement was used for the post cementation. Four slices per tooth were obtained for the push-out tests. Next, 160 blocks of resin composite were first produced for the MTBS tests; their bonding surfaces were conditioned (as mentioned, ie, eight treatments), and they were cemented to each other. The 80 sets (n=10/treatment) were then cut into microbars (16/set): eight were immediately tested, while the other eight were thermocycled (12,000×) and stored (120 days) before MTBS. Failure modes and topographic analyses were performed after treatments. There was no statistically significant difference for the push-out results. In MTBS, surface treatment and silanization had a significant effect (p<0.001). Aging decreased bond strength for all groups. Considering the aged groups, air abrasion promoted the highest values and silanization improved bond strength for all treatments except air abrasion. The alumina particle air abrasion of the relining resin composite promoted the highest bond strengths when luting with self-adhesive resin cement.

Grinding of composite cores using diamond burs with different grit sizes

Aim: To evaluate the retention of Y-TZP crowns cemented in aged composite cores ground with burs of different grit sizes. Methods: Sixty composite resin simplified full-crown preparations were scanned, while 60 Y-TZP crowns with occlusal retentions were milled. The composite preparations were stored for 120 days (wet environment-37°C) and randomly distributed into three groups (n=20) according to the type of composite core surface treatment. The groups were defined as: CTRL (control: No treatment), EFB (extra-fine diamond bur [25μm]), and CB (coarse diamond bur [107μm]). The grinding was performed with an adapted surveyor standardizing the speed and pressure of the grinding. The intaglio surfaces on the crowns were air-abraded with silica-coated alumina particles (30 μm) and then a silane was applied. The crowns were cemented with self-adhesive resin cement, thermocycled (12,000 cycles; 5/55°C), stored (120 days) and submitted to aretention test (0.5mm/min). The retentive strength data (MPa) were analyzed using one-way analysis of variance and Tukey test, as well as Weibull analysis. Failures were classified as 50C (above 50% of cement in the crown), 50S (above 50% of cement in the substrate) and COE (composite core cohesive failure). Results: No statistical difference was observed among the retention values (p=0.975). However, a higher Weibull modulus was observed in the CTRL group. The predominant type of failure was 50S (above 50% of cement in the substrate composite). Conclusion: The retention of zirconia crowns was not affected by grinding using diamond burs with different grit sizes (coarse/extra-fine) or when no grinding was performed.

Laser Treatment for Melanin Gingival Pigmentations: A Comparison Study for 3 Laser Wavelengths 2780, 940, and 445 nm.

The normal appearance of the gingiva is pink to light red, and this appearance may change due to many factors and might be noticeable causing aesthetic concerns. In the Gulf area, the gingival melanin pigmentation is of the main type of concern, and patients expect the pigmentation to be removed for aesthetic reasons. Many techniques have been used to remove the melanin pigmentation such as using surgical blades, diamond or ceramic burs, chemicals, and lasers. This study is comparing the results of three lasers (Er, Cr, YSGG 2780 nm, Diode 940 nm, and 445 nm) in the removal of melanin gingival depigmentation. Clinical outcome parameters including bleeding, wound healing, pain, duration of procedure, color improvement, patient satisfaction, and relapse rate after 2 years were assessed. Conclusion. Within the limitation of this study, all three wavelengths were fast, effective in peeling the pigmentations and well tolerated by the patients. The esthetical results were excellent, and the patients were highly satisfied. Suggestion. To have a bigger number of samples in future papers, and histological studies might be included to explore the different impacts of each wavelength on the gingival melanin pigmentation specifically and on the gingival tissue generally.

Surface Characterization of Monolithic Zirconia Following Treatment with Different Polishing Techniques

The purpose of this study was to evaluate the effects of different polishing techniques on the topographical features and phase transformation of monolithic zirconia. Four brands of zirconia were ground and polished using one of four systems. All zirconia specimens were ground with a fine-grit diamond bur (GB) prior to polishing procedures. The surface roughness and phase transition (XRD) were evaluated, and surface characterizations (SEM and XPS) were performed. The highest roughness was obtained with the Tob system. The strongest diffraction peak in the obtained XRD patterns was at 2θ=30.246°. No monoclinic phase change was found in any group. The XPS analysis showed that the atomic percentages of yttrium in the specimens of Cercon before and after polishing were the highest of any sample. All the polishing systems tested may not adversely affect the phase transformation of monolithic zirconia. The Tob system resulted in the highest roughness. The XPS analysis showed that grinding and polishing had some effects on the properties of zirconia from a microscopic point of view.

Spectrophotometric analysis evaluating apical microleakage in retrograde filling using GIC, MTA and biodentine: an in-vitro study

BackgroundThe present study compares the apical microleakage of three different root-end filling materials in which the retrograde cavity is prepared by two different burs.MethodsEighty extracted single rooted maxillary and mandibular premolars were taken. Root canal treatment was completed. Apical 3 mm of all the teeth were resected with diamond disk. The tooth were divided into four groups with two subgroups for each group containing 10 tooth (N = 10) as: Group IA (Negative Control and IB (Positive Control); Group IIA and IIB: Prepared with round carbide bur and round diamond bur respectively, filled with GIC; Group IIIA and IIIB: Prepared with round carbide bur and round diamond bur respectively, filled with MTA; Group IVA and IVB: Prepared with round carbide bur and round diamond bur, filled with Biodentine. After applying two coats of nail varnish leaving apical 3 mm (except for negative control group) all teeth were immersed in 2% methylene blue for 3 days and again in 65% nitric acid for next 3 days for extraction of dye. The obtained solution was then transferred to eppendorf tube and centrifuged in microcentrifuges at 14,000 revolution per minutes (RPM) for 5 min. Optical density or absorbance of the supernatant solution was measured with UV spectrophotometer at 550 nm.ResultsThe absorbance of the supernatant solution after dye extraction is decreasing in the order of positive control> GIC > MTA > Biodentine> negative control group. The significant difference was observed between GIC and MTA (p = 0.0001) and GIC and Biodentine (p = 0.0001) with two different burs but statistically non-significant difference was observed between MTA and Biodentine with Carbide bur (p = 0.127) and Diamond bur (p = 0.496) respectively.ConclusionsWithin the limitations of the present study, it can be concluded that Biodentine and MTA showed less microleakage as compared to GIC. There is no significant difference between mean microleakage of MTA and Biodentine. However, the mean OD of the Biodentine was least of all evaluated materials. Preparation of the root-end using round carbide bur as well as round diamond burs showed comparable microleakage for all three filling materials.

Experimental implantoplasty outcomes correlate with fibroblast growth in vitro

BackgroundImplantoplasty is an option in peri-implantitis treatment, but little is known about the effect on the soft tissue. The aim of the study was to characterize surface roughness following experimental implantoplasty and to examine its effect on human fibroblast growth and secretion of selected proteins.MethodsTitanium grade IV coins were mechanically treated with six different rotating bur sequences; diamond burs or carbide burs alone, or followed by either Arkansas stone bur or silicone burs. Machined and rough-surface sandblasted, acid-etched (SLA) coins were used as control. The surface topography was characterized by scanning electron microscope and profilometer. Human gingival fibroblasts from two donors were cultured on the coins to quantify the effect on cell morphology, growth, and protein secretion by confocal microscopy and multiplex immunoassay.ResultsAll surface roughness parameters were lower for the surfaces treated with experimental implantoplasty than for the SLA surface, and the sequence of carbide burs followed by silicone burs rendered the least rough surface of the test groups. The implantoplasty procedures changed the elemental composition of the titanium surface. High surface roughness showed a weak to moderate negative correlation to fibroblast growth, but induced a higher secretion of VEGF, IL-6 and MCP-3 to the cell medium compared to the least rough surfaces of the test groups. At day 30 fibronectin levels were higher in the SLA group.ConclusionsThe surface roughness following implantoplasty demonstrated a weak to moderate negative correlation with the growth of fibroblasts. The addition of Arkansas stone and silicon burs to the experimental implantoplasty bur protocol rendered an initial increase in fibroblast growth. Implantoplasty altered the elemental composition of the titanium surface, and had an effect on the fibroblast cytokine secretion and fibronectin levels.

Effect of laser application on microtensile bond strength of an orthodontic adhesive to water-aged composite.

This study evaluated the microtensile bond strength (MTBS) of an orthodontic adhesive to water-aged composite surfaces using different surface treatments. Twelve composite blocks (10 mm × 10 mm × 5 mm) were fabricated and randomly divided into two groups. Half of the specimens were stored in distilled water for 1 day, and the other specimens were stored for 30 days. The specimens were randomly assigned to six groups according to surface treatments (n = 15): Group 1, control (no treatment); Group 2, phosphoric acid; Group 3, diamond bur; Group 4, diamond bur + phosphoric acid; Group 5, laser; and Group 6, laser + phosphoric acid. One coat of orthodontic adhesive was bonded to one surface of composite blocks, and a microhybrid composite resin was bonded to the surfaces via a Teflon mold. Bond strength was evaluated using an MTBS test. Surface topography was evaluated using scanning electron microscopy (SEM) analysis. The data were analyzed using one-way analysis of variance, Tamhane post-hoc test, and independent sample t-tests (P < 0.05). Bond strength values tended to decrease in all groups (with the exception of Group 2) after storage in water for 30 days (P < 0.05). Laser and diamond bur application (with or without phosphoric acid) enhanced the bond strength. An Er,Cr:YSGG laser application may be a feasible alternative to diamond bur for enhancing the bond strength of orthodontic adhesive to composite resin.

The effect of repeated surface treatment of zirconia on its bond strength to resin cement.

PURPOSEThe aim of this study is to evaluate the influence of repeated surface treatments on wettability and surface roughness for zirconia surface and bond strength of zirconia-based ceramics to resin cement.MATERIALS AND METHODSSeventy blocks (10 × 10 × 3 mm) of zirconia-based ceramics were fabricated and divided into two groups according to the surface treatments: (A) 110 µm Al2O3 airborne-particle abrasion and (R) 110 µm silica modified Al2O3 airborne-particle abrasion. At stage 2, each group was subdivided into 5 groups according to the surface retreatments: (a) 110 µm Al2O3 airborne-particle abrasion, (r) 110 µm silica modified Al2O3 airborne-particle abrasion, (D) diamond bur, (Da) diamond bur + 110 µm Al2O3 airborne-particle abrasion, and (Dr) diamond bur + 110 µm silica modified Al2O3 airborne-particle abrasion. Cylinders of self-adhesive resin cement were cemented onto each treated ceramic surface and subjected to micro-shear bond strength test. Additional specimens were prepared for roughness and wettability analyses. The data were subjected to t-test and One-way ANOVA followed by Tukey's post hoc test (α=.05).RESULTSAt stage 1, group R presented higher bond strength values than group A (P=.000). There was a statistically significant increase of bond strength at stage 2 for group A (P=.003). The diamond bur influenced the surface roughness, increasing the values (P=.023). Group R provided better wettability. Regardless of the applied surface treatment, most of failures were adhesive.CONCLUSIONThe combination of application and reapplication of Rocatec Plus showed the best results of bond strength. Surface retreatment and recementation might be an indicated clinical strategy.

Effect of Composite Age on the Repair Bond Strength after Different Mechanical Surface Pretreatments.

To investigate the reparability of aged and fresh resin composite after different mechanical surface pretreatments. Sixty composite specimens (Filtek Supreme XTE, 3M Oral Care) were either aged by thermal cycling (5000 cycles, 5-55°C) and six months of water storage, or immediately processed within 5 min after polymerization. Both aged and fresh specimens were either ground with fine (46-µm) or coarse (100-µm) diamond burs and then silanized or sandblasted with aluminum oxide (Al2O3) and silanized. In the negative control group, no mechanical surface pretreatment or silanization was performed. Specimens (n = 6 per group) were repaired with an adhesive (OptiBond FL, Kerr) and a resin composite (Filtek Supreme XTE). Directly adhered composite-to-composite increments served as the positive control group. After thermoycling, microtensile repair bond strength was assessed and statistically analyzed (α = 0.05). Aged composite surfaces revealed significantly lower repair bond strength than immediately repaired composite. The negative control group demonstrated the significantly lowest microtensile bond strength of all groups. No significant differences in repair bond strength were observed between the different mechanical pretreatments for both aged and fresh specimens. The repair bond strength of fresh composite pretreated with a fine diamond bur + Al2O3 + silane or a coarse diamond bur with/without Al2O3 + silane did not differ significantly from the positive control group. The age of the repaired composite has a greater influence on repair bond strength than does the type of composite surface pretreatment.

Effects of Double Application of a Resin Cement Primer and Different Diamond Burs on Cement-Dentin Bond Strength.

To evaluate the effects of double application of resin cement primers to dentin prepared with different diamond burs on the cement-dentin bond strengths. Sixty flat dentin surfaces were prepared and divided into 12 groups (n = 5) according to three experimental factors: 1. resin cements: RelyX Ultimate (RU), Multilink Automix (ML), and Panavia V5 (PV); 2. resin cement primer application: single or double; 3. dentin surface preparation with regular or superfine diamond burs. Cement-dentin sticks (1 mm2) were prepared for and underwent microtensile bond strength testing (µTBS). Statistical analysis was performed using three-way ANOVA and Duncan's test (α = 0.05). Fractured surfaces and cement-dentin interfaces were observed using SEM. Additional teeth were used to observe the demineralization effect of resin cement primers with SEM and transmission electron microscopy (TEM). All tested factors demonstrated significant effects on µTBS (p < 0.001). The combination of PV with superfine-grit bur and double application yielded the highest bond strengths. Surfaces prepared with superfine-grit burs demonstrated higher µTBS than did the regular-grit group, but a significant effect was not observed for all groups. The double application of primer significantly increased the bond strength for most combinations, except for PV with superfine-grit bur-prepared dentin. PV showed higher bond strengths than other resin cements. Double application of primer improved the bond strength of all cements to dentin. Bond strengths were higher when dentin was prepared with a superfine-grit bur.

Microleakage of novel glass ionomer restoration in cavities prepared by Er,Cr:YSGG laser: An in-vitro study

Aim: To compare the microleakage of novel materials containing glass ionomer, which are applied to standard class V cavities prepared by Er,Cr:YSGG (erbium, chromium-doped yttrium, scandium, gallium, and garnet) laser and by conventional diamond bur in primary teeth. Materials and Methods: Fifty non-carious primary molar teeth were randomly divided into five main groups and restored with various materials containing glass ionomers (Group 1: Equia System; Group 2: Fuji IX GP; Group 3: Fuji II LC; Group 4: Dyract Extra; and Group 5: Giomer). Each group was divided into two subgroups according to laser and conventional preparation methods. Results: As for the gingival margin, in terms of leakage values, no statistically significant difference was observed between drill and Er,Cr:YSGG laser although less microleakage values were obtained in Er,Cr:YSGG laser groups 1 and 4 (P > 0.05). Among groups prepared by drill, the lowest leakage rates observed at the gingival margin are Equia System, Giomer, Dyract Extra, Fuji II LC, and Fuji IX GP, respectively. Among groups prepared by Er,Cr:YSGG laser, the lowest leakage rates observed in the gingival edge are Equia System, Giomer = Dyract Extra, Fuji IX GP, and Fuji II LC, respectively. Conclusion: Occlusal and gingival microleakage scores were the lowest in the groups restored with Equia system in the cavities prepared by both diamond bur and laser system. Equia system consisting of high-viscosity glass ionomer cement and nano-filled surface coat G-Coat Plus materials could be used successfully in pediatric dentistry.

Influence of the Coca-Cola Drinks on the Overall Color of Glazed or Polished Porcelain Veneers Fabricated from Different Materials and Thicknesses: An In Vitro Study

The aim of the current study is to assess the influence of Coca-Cola drinks on the overall color of glazed or polished porcelain veneers fabricated of three different porcelain systems and two different thicknesses. A total of 96 ceramic disk specimens were fabricated. The ceramic veneers were prepared to a standardized thickness of 1.0 mm ± 0.025 mm and 0.6 ± 0.025 (48 samples each group) using the following ceramic systems: Zircon, E-max press, and E-max CAD/CAM. Veneer samples from each system were divided into two subgroups (n = 8). First subgroup samples were glazed according to the manufacturer's instructions, and the other subgroup samples were adjusted with diamond burs then polished with ceramic polishing kit. Color was measured with Vita Easyshade spectrophotometer. Then all samples immersed with Cola drink, for 4 weeks, in a thermocycling machine and then the color were measured again and color change was recorded. Significant differences in color change were noticed before and after immersing with Coca-Cola and thermocycling for all materials and thicknesses used (p < 0.01). Significant differences in color changes were noticed between glazed and polished samples (p < 0.001). No significant differences in color change were noticed when using different thicknesses for all materials used (p < 0.05). Different porcelain materials have shown significant color changes after immersing and thermocycling in Coca-Cola drinks. The color changes of polished porcelain specimens were more considerable than those of polished specimens for all porcelain materials and thicknesses used. This suggests reglazing of all esthetic restoration after any adjustments might be performed and before final cementation in an attempt to maintain the color stability in oral environment. To achieve a perfect color stability of ceramic veneers, clinicians should take into consideration the possible color deviations that might result after any adjustment followed by polishing procedures to the ceramic surface. And, it is always preferable to do reglazing of porcelain restorations after any surface treatments and before final cementation.

Influence of aerated drink, mouthwash, and simulated gastric acid on the surface roughness of dental ceramics: A comparative In Vitro study

ABSTRACTBackground:Dental ceramics are known for their natural appearance and their durable chemical and optical properties, and their uses mainly reflect their excellent aesthetic properties, biocompatibility and resistance to wear. In addition, dental ceramics are considered to be chemically inert restorative material with large differences in the chemical compositions and microstructures. Although ceramics exhibit excellent physical properties and biocompatibility, the oral environment presents a series of external factors that affect its physical and mechanical properties in its long term function.Aims and Objectives:The aim of this study is to compare and evaluate the surface roughness of 2 dental ceramics (Noritake® & IPS Emax ceram) before and after exposure to an aerated drink, a mouthwash and simulated vomit solution with distilled water.Materials and Methods:128 ceramic discs were made, 16 for each of the 4 groups of 2 ceramics to be tested. It was fabricated in the form of discs of diameter 10 mm × 2 mm thickness. The test specimens were calibrated by grinding, using a medium grit diamond bur. Both the above specimens were divided into 4 groups of 16 each. They were then subjected to test solutions. Each specimen in a group was immersed in the following solutions: Coca-Cola, chlorhexidine mouthwash, simulated vomit solution and distilled water.Results:The results analyzed statistically using one way ANOVA (analysis of variance), paired t test and independent t test.Conclusion:Within the limitations of this study, it was concluded that the surface roughness of the evaluated ceramics increased upon exposure to Coca-Cola, chlorhexidine mouthwash and simulated vomit solution. Simulated vomit solution caused the maximum change in surface roughness followed by coca cola and then chlorhexidine mouthwash. No changes were observed after immersion in distilled water. Noritake® showed slightly more resistance to change in surface profile when compared to IPS e.max.

Accuracy of working length measurement with endo motor having built-in apex locator and comparison with periapical radiographs.

To determine the accuracy of working length measurement with endomotor having builtin apex locator by comparing it with periapical radiographs. The cross-sectional study was conducted at the Department of Operative Dentistry, Dr Ishrat-ul-Ibad Khan Institute of Oral Health Sciences, Dow University of Health Sciences, Karachi, from January to June 2014, and comprised permanent maxillary anterior teeth with mature apices. A preoperative radiograph was taken by using standardised paralleling technique. The access cavity was prepared by a high speed water-cooled diamond bur. After doing initial filing and drying the canal, the working length was taken with an endomotor with built-in apex locator in dual mode using the Protaper Rotary File S1. The length was measured using a millimeter scale. After attaining tentative working length from the pre-operative radiograph, 1mm was subtracted from the radiographic apex. A stainless steel K-file was placed in the canal at this length and a radiograph was taken by paralleling technique using intraoral film holder. The electronic and radiographic findings were noted. Accuracy was considered positive if the endomotor reading was 0-2mm short of the radiographic working length. Data was analysed using SPSS 16. Of the 96 cases, working length with X-Smart Dual was acceptable in 85(88.5%) cases, and unacceptable in 11(11.5%) cases. Accuracy of working length measurement with endomotor having built-in apex locator was found to be a better measuring tool compared to the conventional periapical radiographs.

Evaluation of shear bond strength of amalgam restorations repaired with composite resin by different surface treatments

Aim: Repairing amalgam restorations with composite resins is a clinical practice with many advantages. An effective adhesion is achieved between amalgam and composite by applied different surface treatment on amalgam surface. In this study, the effect of adhesive systems applied on amalgam surface on composite-amalgam connection was investigated.&#x0D; Methodology: Standard cavities were opened in 70 acrylic molds that had completed their polymerization and amalgams were placed in these cavities. Seven groups were randomly assigned to different surface treatments on amalgam. In group 1 only roughening with diamond bur , in group 2 acid etch, in group 3 acid application after roughening with diamond bur, in group 4 roughening with diamond bur and silane, in group 5 acid etch and silane, in group 6 roughening with diamond bur and Alloy Primer and finally 7. acid etch and Alloy Primer was applied in the samples. After the application of clearfil universal bond to all groups, composite resins were placed and polymerized. Shear bond strengths were tested with a Universal testing machine. Obtained data were evaluated by one way ANOVA and Tukey B tests.&#x0D; Results: In the statistical evaluation of the groups, the highest shear bond strength between amalgam-composite was seen in the 3rd group where both roughening with diamond bur and acid were applied together, and the lowest shear bond strength was seen in the first group with only roughening with diamond bur. The differences between the groups were statistically significant (p &lt;0.05).&#x0D; Conclusion: The roughening of the amalgam surface affects the shear bond strength between amalgam and composite resin. These results obtained in vitro conditions should be supported with clinical studies.&#x0D; &#x0D; How to cite this article: Cangül S, Adıgüzel Ö, Erpaçal B, Ünal M, Acartürk M, Satıcı Ö. Evaluation of shear bond strength of amalgam restorations repaired with composite resin by different surface treatments. Int Dent Res 2019;9(3):105-10.&#x0D; &#x0D; Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

The Effect of Betel Quid Extract on Wound Healing Process in Male Wistar Rats (Rattus norvegicus L.)

Wound can be occured during dental treatment. In outline, there are several phases of wound healing; inflammatory phase, proliferative phase, and maturation phase. Various drugs in various forms are used to accelerate the healing process, but mostly they have side effects. Therefore, traditional medicine, such as betel quid consisted of betel leaf, areca nut, gambier, and calcium hydroxide, is developed. The aim of this study was to investigate the effect of wound healing process in male Wistar rats. A total of 30 male Wistar rats were taken and divided into 5 groups: Group 1, 2, and 3 (K1,K2, K3) were given 5%, 10% and 15% concentrations of betel quid extract oinments; Group 4 (K4) was positive control (hyaluronic acid 0.2% oinment); Group 5 (K5) was negative control (placebo oinment). One mm- diameter of lower lip mucosal wounds on rats were created by using cylinder diamond bur. The oinments were applied twice daily for 10 days. The number of netrophils on first and third day were measured and the thickness of ephitelium on 10 days were determined. All groups of betel quid extracts exhibited the reduction of the number of neutrophils on inflammatory phase. Group 3 shown as the highest effect and had no significant different with positive control. Betel quid extracts in all groups also improved epithelial thickness on proliferative phase, in which group II and group III had no significant different with positive control. Betel quid extract had effect on wound healing process in male Wistar rats due to its ability in supressing inflamation and in increasing reepithelization.

Influence of Computer-aided Design/Computer-aided Manufacturing Diamond Bur Wear on Marginal Misfit of Two Lithium Disilicate Ceramic Systems.

Marginal misfit of monolithic lithium disilicate ceramic crowns obtained from a chairside computer-aided design/computer-aided manufacturing system is affected after successive millings using a single diamond bur set. This fact can be critical for the longevity of indirect restorations.

Effect of different repair methods on the bond strength of resin composite to CAD/CAM materials and microorganisms adhesion: An in situ study

ObjectiveTo evaluate the influence of different repair protocols andin situ aging on colony forming units (CFU) and shear bond strength (SBS) between CAD/CAM materials and resin composite. Methodology150 blocks (6 × 5 × 2.5 mm) were made out of each restorative material (CAD/CAM resin composite -RC), polymer-infiltrated ceramic - PIC and glass ceramic (VS), totaling 450 blocks. Fifty blocks of each material were submitted to a 60-day in situ aging by fixing the blocks into cavities prepared in the posterior region of the base of complete dentures. The aged and non-aged blocks were randomly divided into 30 groups of 10 (N = 300) according to the following factors: “Restorative material”, “Surface Treatment”, and “Aging”. Z350 resin composite cylinders were made on the surface of the blocks, and the specimens were submitted to thermocycling, shear test, failure mode analysis, and complementary analyses of roughness, fungal and bacterial CFUs, SEM, and EDS. The SBS (MPa) and CFU/mL data were statistically analyzed by ANOVA and Tukey’s test (5%). The other variables were analyzed by qualitative analyzes. ResultsThe "aging" factor was significant for RC and VS and the "surface treatment" factor was significant for the three restorative materials. Hydrofluoric (HF) acid etching followed by silanization was the best protocol for PIC and VS and diamond bur + SBU was the best protocol for RC. CFU/mL was similar among the restorative materials. ConclusionIn situ aging reduced the bond strength between the resin composite repair and RC and VS materials. Clinical SignificanceThe repair protocol for each restorative material is different and may be influenced by the time of clinical use.