Sadaaki Murahara’s research while affiliated with Kagoshima University and other places

What is this page?


This page lists works of an author who doesn't have a ResearchGate profile or hasn't added the works to their profile yet. It is automatically generated from public (personal) data to further our legitimate goal of comprehensive and accurate scientific recordkeeping. If you are this author and want this page removed, please let us know.

Publications (15)


Fig. 2 Tensile bond strength (MPa) of the different groups. Same lowercase letters indicate no significant difference among surface treatment groups without thermal cycling. Same uppercase letters indicate no significant difference among surface treatment groups with 10,000 thermal cycles. * indicates no significant difference within the same surface treatment group before and after thermal cycling.
Materials used in this study
Bond strength of 4META-MMA-TBB resin to a CAD/CAM composite resin block and analysis of acetone-insoluble cured resin residues at adhesive interfaces
  • Article
  • Full-text available

October 2024

·

12 Reads

Dental Materials Journal

Sadaaki MURAHARA

·

Asami UENODAN

·

Hiroaki YANAGIDA

·

Hiroyuki MINAMI

This study investigated the adhesion of 4META-MMA-TBB resin to CAD/CAM composite resin blocks. CAD/CAM composite resin blocks were subjected to alumina blasting, ceramic primer treatment, or both, and then bonded with 4META-MMA-TBB resin. The tensile bond strength of 4META-MMA-TBB resin to blocks without surface treatment was approximately 20 MPa, but with surface treatment, it significantly improved to approximately 40 MPa. Cohesive failure was observed in some blocks with surface treatment with both alumina blasting and ceramic primer. As a result of Soxhlet extraction of the adhesive interface with acetone solvent and FT-IR spectrum analysis, it was found that PMMA remained on the block surface when surface treatment with both alumina blasting and ceramic primer were performed. These results demonstrated that the bond strength of 4META-MMA-TBB resin is significantly improved when both alumina blasting and ceramic primer are applied as surface pretreatment to the CAD/CAM composite resin block.

Download

Physical properties of experimental light-curing pattern resins based on poly (n-butyl methacrylate) or poly(iso-butyl methacrylate)

July 2024

·

28 Reads

Dental Materials Journal

Akihiko KADOKAWA

·

Sadaaki MURAHARA

·

Hiroshi KONO

·

[...]

·

Hiroyuki MINAMI

Experimental light-curing pattern resins were fabricated to produce pattern resin materials with adequate dimensional stability. The light-curing pattern resins consisted of poly(n-butyl methacrylate) or poly(iso-butyl methacrylate) (PiBMA) polymers and methacrylate monomers. The physical properties, amount of residual ash after burning, Vickers hardness, flexural strength, and volumetric polymerization shrinkage of each material were determined. The data obtained for the prepared resins were compared with those of a commercially available pattern resin, Palavit G (PG). A lower amount of residual ash was observed for some of the prepared resins than for PG. The Vickers hardness and flexural strength values of all experimental resins were lower than those of PG. The volumetric polymerization shrinkage of all the experimental resins based on PiBMA was lower than that of PG. These results suggest that acrylic light-curing resin materials based on PiBMA may be useful for patterning and indexing during soldering.


A clinical case of occlusal reconstruction using a maxillary cross-arch bridge for a patient with severe periodontal disease

May 2016

·

18 Reads

Annals of Japan Prosthodontic Society

Patient: The patient, a 55-year-old woman, complained of bleeding and pus discharge from the maxillary anterior gingiva. The patient was diagnosed as having severe generalized periodontitis with a defective prosthesis. Periodontal therapy and occlusal improvement using provisional prostheses were performed together. As the final prostheses, a cross-arch bridge in the maxilla and bridges in the mandible were placed. Thereafter, she has remained satisfied without the previous complaints. Discussions: Accurate transfer of the crown shape from the provisional prostheses to the final ones and subsequent maintenance accounted for the good prognosis. Conclusion: Appropriate periodontal and occlusal therapy for this periodontally compromised patient has led to a good course for more than 5 years since the final restoration.


Effect of metal conditioner on bonding of porcelain to cobalt-chromium alloy

February 2016

·

759 Reads

·

7 Citations

The Journal of Advanced Prosthodontics

Purpose: The purpose of this study was to evaluate the efficacy of two different metal conditioners for non-precious metal alloys for the bonding of porcelain to a cobalt-chromium (Co-Cr) alloy. Materials and methods: Disk-shaped specimens (2.5×10.0 mm) were cast with Co-Cr alloy and used as adherend materials. The bonding surfaces were polished with a 600-grid silicon carbide paper and airborne-particle abraded using 110 µm alumina particles. Bonding specimens were fabricated by applying and firing either of the metal conditioners on the airborne-particle abraded surface, followed by firing porcelain into 5 mm in diameter and 3 mm in height. Specimens without metal conditioner were also fabricated. Shear bond strength for each group (n=8) were measured and compared (α=.05). Sectional view of bonding interface was observed by SEM. EDS analysis was performed to determine the chemical elements of metal conditioners and to determine the failure modes after shear test. Results: There were significant differences among three groups, and two metal conditioner-applied groups showed significantly higher values compared to the non-metal conditioner group. The SEM observation of the sectional view at bonding interface revealed loose contact at porcelain-alloy surface for non-metal conditioner group, however, close contact at both alloy-metal conditioner and metal conditioner-porcelain interfaces for both metal conditioner-applied groups. All the specimens showed mixed failures. EDS analysis showed that one metal conditioner was Si-based material, and another was Ti-based material. Si-based metal conditioner showed higher bond strengths compared to the Ti-based metal conditioner, but exhibited more porous failure surface failure. Conclusion: Based on the results of this study, it can be stated that the application of metal conditioner is recommended for the bonding of porcelain to cobalt-chromium alloys.


Effect of adherend temperature on bond strengths of resin bonding systems to denture base resin and a semi-precious alloy

March 2013

·

8 Reads

·

3 Citations

Dental Materials Journal

This study investigated the effect of adherend temperature on shear bond strengths of auto-polymerizing resin to denture base resin and 4-META/MMA-TBBO resin to silver-palladium-copper-gold (Ag-Pd-Cu-Au) alloy. Bonding procedure was carried out when adherend temperature was 10, 23, 37, or 55°C, and shear bond strengths (SBSs) were measured before and after thermocycling. Before thermocycling, there were no significant differences in bond strength among the four adherend temperatures for each adhesive resin: 31.59±6.11-32.89±2.12 MPa for auto-polymerizing resin; 35.43±2.2-38.38±0.61 MPa for 4-META/MMA-TBBO resin. After thermocycling, optimal adherend temperature to achieve the highest bond strength was 37°C for auto-polymerizing resin to denture base resin (30.02±2.29 MPa) and 10ºC for 4-META/MMA-TBBO resin to Ag-Pd-Cu-Au alloy (37.14±2.17 MPa).


Effect of adhesion promoting monomer addition to MMA-TBBO resin on bonding to pure palladium

February 2013

·

21 Reads

·

6 Citations

Dental Materials Journal

This study evaluated the effects of combined use of metal primers and modified monomers on the bonding of MMA-TBBO resins to pure palladium (Pd). Bonding surface was polished with 600-grit silicon carbide paper and primed with one of these four metal primers: V-Primer, M. L. Primer, Metaltite, or Alloy Primer. Four monomers, including three modified ones, were added to MMATBBO resin. One was a methyl methacrylate monomer containing no adhesion promoting monomers, while the other two modified monomers contained the functional monomer of either V-Primer or Alloy Primer. Bonded specimens were prepared by incremental build-up of MMA-TBBO resin on primed Pd surfaces. Shear bond strengths were measured after thermal cycling. Bonding to Pd was significantly improved when modified monomer containing the functional monomer of Alloy Primer was used in combination with M. L. Primer or Metaltite applied on the bonding surface.


Effects of metal primers on the bonding of an adhesive resin cement to noble metal ceramic alloys after thermal cycling

December 2011

·

27 Reads

·

19 Citations

Journal of Prosthetic Dentistry

Although the effectiveness of primers for resin bonding to noble alloys has been demonstrated, no effective clinical technique for bonding to noble metal ceramic alloys has been established. The purpose of this study was to evaluate the effects of metal primers on the shear bond strength of an adhesive resin to noble metal ceramic alloys after thermal cycling. Sixty-three disk-shaped specimens (10 × 2.5 mm) were cast from high-gold-content alloys (Super Metal W-85: W85 or IFK88 GR: IFK88), a high-palladium-content alloy (Super Metal N-40: N40), and an Ag-Pd-Cu-Au alloy (Castwell M.C.12: MC12). Smaller-sized disk-shaped specimens (8 × 2.5 mm) were fabricated with MC12. Bonding surfaces were finished with 600-grit SiC-paper and airborne-particle abraded with 50-μm alumina. Pairs of disks were primed (V-Primer: VP; ML Primer: ML; or Metaltite: MT) and bonded with an adhesive resin (Super-Bond C&B). The bond strengths were determined before and after 20,000 and 50,000 thermal cycles (n=7). Data were analyzed by using a 3-way ANOVA and the Bonferroni test (α=.05). Failure modes were determined by optical microscope and SEM observation. Bond strengths to high-gold-content alloys with VP and MT significantly decreased after the thermal cycling (P<.001). Bond strengths to W85 (35.27 ±4.25 MPa) and IFK88 (33.57 ±3.56 MPa) after 50,000 thermal cycles obtained by ML were the highest (P<.001), and these groups showed combination failures. Bond strengths to N40 significantly decreased after 50,000 thermal cycles (P<.001), regardless of primers. Shear bond strengths (SBS) to high-gold-content alloys were not degraded up to 50,000 thermal cycles when primed with ML. None of the primers evaluated was effective for high-palladium-content alloy.


In vitro Wear of Provisional Restorative Resins

July 2010

·

10 Reads

Objectives: The purpose of this study was to evaluate the wear rates of provisional restorative materials by in vitro system. Methods: Disk specimens (3.0mm thick, 8.0mm diameter) were fabricated with tested materials including a chemical-polymerizing acrylic resin with TMPT filler (Provista, Sun Medical), two chemical-polymerizing acrylic resins (Metafast, Sun Medical and UnifastIII, GC), two photo-polymerizing acrylic resins (Unifast LC, GC and Hardbite, Yoshida), and two chemical-polymerizing composite resins (Protemp Plus, 3M ESPE and Luxatemp, DMG). The specimens were secured to brass cups with an auto-cured acrylic and fixed to the UAB wear simulator. Localized wear test was carried out using a hemispherical steel tip and a PMMA/water slurry with 75 N at 1.2 Hz for 100,000 cycles. Wear depths were measured using a non-contact profilometer (Proscan2000, Scantron Industrial). The data (n=5) were statistically analyzed with one-way ANOVA and Tukey's test (=0.05). Results: The results of the wear tests are presented in the table below. Groups with identical letters are not significantly different (p>0.05). Conclusion: The mean wear values of composite materials were significantly lower than all other materials except Provista. The mean wear value of Provista was significantly lower compared to other chemical-polymerizing acrylics. There were no significant differences among two photo-polymerizing acrylics and two chemical-polymerizing acrylics.


In vitro Wear of a Novel Composite Crown System

March 2010

·

24 Reads

Objectives: A novel composite crown system with a fiber-reinforced composite (Metacolor Prime Art, Sun Medical) has recently been introduced. The purpose of this study was to evaluate the wear of the fiber-reinforced composite according to the change of thickness of the overlying indirect composite. Methods: Disk specimens (1.5mm thick, 8.0mm diameter) of various thicknesses (shown in the upper row of the table) of the indirect composite (Metacolor Prime Art, Sun Medical) were fabricated on top of fiber-reinforced composite (Jacket Opaque, Sun Medical). They were then cemented onto Ni-Cr alloy disks (REX4, Pentron) using a resin cement (C&B Metabond, Parkell). Those specimens were secured inside brass cups with an auto-cured acrylic and inserted into the UAB wear simulator. Localized wear was carried out using a hemispherical steel tip and a PMMA/water slurry for 200,000 cycles with 75 N of force at a 1.2 Hz loading frequency. Wear depths were measured using a non-contact profilometer (Proscan2000, Scantron Industrial). The data were statistically analyzed with one-way ANOVA and Tukey's test (a=0.05). Results: The results of the wear tests are presented in the table below. Conclusion: The wear of Metacolor Prime Art was influenced by the thickness of the overlayed indirect composite. When the thickness of indirect composite was 0.1 mm or less, the underlying fiber-reinforced composite was exposed and worn rapidly.


Effects of metal primers on bonding of adhesive resin cement to noble alloys for porcelain fusing

March 2010

·

323 Reads

·

34 Citations

Dental Materials Journal

This study evaluated the effects of metal primers on the bonding of adhesive resin to four pure metals (Au, Pd, Ag, Cu) and two noble alloys for porcelain fusing (high-gold and high-palladium content alloys). Bonding surface was polished with 600-grit silicon carbide paper and primed with one of the three metal primers (V-Primer, Metaltite, and M.L. Primer). Bonded specimens were fabricated by applying adhesive resin (Super-Bond C&B) on the primed surface. Shear bond strength (SBS) was determined both before and after thermocycling (4-60 degrees C for 2,000 cycles). The highest SBS values to each pure metal after thermocycling were 33.5 MPa for Au by M.L. Primer, 35.0 MPa for Ag by V-Primer, and 34.4 MPa for Cu by Metaltite. SBS to high-gold content alloy after thermocycling was 33.3 MPa by M.L. Primer. None of the primers was effective for pure Pd and high-palladium content alloy after thermocycling.


Citations (9)


... Another treatment described is the use of a bonding agent 12,24 , which has a higher cost and the applied layer thickness is difficult to standardize, interfering with MCBS 12,15 . Moreover, some proposed protocols require materials that are difficult to access, such as oxidation heat treatment 23,25 , *e-mail: anapaula@forp.usp.br ...

Reference:

Simplified Acid Treatment Technique in Cobalt-Chromium Alloys: Effect on Metal-Ceramic Bond Strength
Effect of metal conditioner on bonding of porcelain to cobalt-chromium alloy

The Journal of Advanced Prosthodontics

... The shear bond strengths of the acrylic resin and two types of zirconia ceramic (Y-TZP and Ce-TZP/A) were evaluated after traditional surface pretreatment, air-abrasion with 50 µm and 0.3 MPa Al 2 O 3 particles (CON) [23], and a novel pretreatment, using a laser to create microslits (MS). Despite the fact that studies on the bonding strength between acrylic resin and metal alloys [32,33] postulate that bonding strength is sufficient for clinical dentistry, the durability after thermal cycling as a means of artificial aging, requires discussing. The results confirmed that the SBS values of MS were higher than that of CON, regardless of artificial aging. ...

Effect of adherend temperature on bond strengths of resin bonding systems to denture base resin and a semi-precious alloy
  • Citing Article
  • March 2013

Dental Materials Journal

... Ever since, 20 sulfur-containing monomers due to the fact that they interact 21 directly to noble metal elements, have been used at the field of 22 clinical dentistry [2][3][4][5]. A primer including both sulfur-containing 23 and acidic adhesive monomers was developed as an effective 24 primer for noble and non-noble metals, achieving a stronger 25 adhesion to noble metals than a sulfur-containing monomer alone 26 [6][7][8][9][10][11]. 27 In recent years, metal allergy problems caused by a dental 28 metal, and problems with aesthetics have resulted in material 29 diversity for restorations and the use of FDP at dental clinics. ...

Effect of adhesion promoting monomer addition to MMA-TBBO resin on bonding to pure palladium
  • Citing Article
  • February 2013

Dental Materials Journal

... The alloy primers may be conveniently categorized based on the reactive acidic moieties present. For the description convenience, an elaborate classification system of the dental alloy primers was devised and exhibited in Table 4. Primers are carboxylic acid-based or their anhydrides, 2,3,8,18,19,[27][28][29][30][31][32][33][34][35][36][37][38][39][40][41] sulfur-containing/ thione-thiol-based, 3,8,14,17,23,24,27,30,32,38,40,[42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61] phosphoric acidbased, 3,19,[27][28][29][30][31][32][33][36][37][38]42,50,[54][55][56]58,[62][63][64][65][66] silicic acid-based, 3,35 and phosphonic acid ester-based. 35,67,68 Combinations of the above primers (binary primers: two monomers with different reactive functional groups; ternary primers: three monomers with different reactive functional groups) were also been employed in the studies. ...

Effects of metal primers on the bonding of an adhesive resin cement to noble metal ceramic alloys after thermal cycling
  • Citing Article
  • December 2011

Journal of Prosthetic Dentistry

... The alloy primers may be conveniently categorized based on the reactive acidic moieties present. For the description convenience, an elaborate classification system of the dental alloy primers was devised and exhibited in Table 4. Primers are carboxylic acid-based or their anhydrides, 2,3,8,18,19,[27][28][29][30][31][32][33][34][35][36][37][38][39][40][41] sulfur-containing/ thione-thiol-based, 3,8,14,17,23,24,27,30,32,38,40,[42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61] phosphoric acidbased, 3,19,[27][28][29][30][31][32][33][36][37][38]42,50,[54][55][56]58,[62][63][64][65][66] silicic acid-based, 3,35 and phosphonic acid ester-based. 35,67,68 Combinations of the above primers (binary primers: two monomers with different reactive functional groups; ternary primers: three monomers with different reactive functional groups) were also been employed in the studies. ...

Effects of metal primers on bonding of adhesive resin cement to noble alloys for porcelain fusing
  • Citing Article
  • March 2010

Dental Materials Journal

... We must not forget that the thickness of the incrustations plays a crucial role, because the light must reach the total of the cementing agent so that it reaches its maximum hardness. From 3 mm thick, hardness is drastically affected cement [47][48][49][50][51]. ...

Effect of fiber-premixed indirect resin composite substructure on fracture resistance of MOD composite inlays adhered with two different adhesive resin cements
  • Citing Article
  • September 2009

Dental Materials Journal

... 17,18 Lining of the pulpal cavity and axial walls A study conducted by Murahara recommended the use of adhesive resin liners to prevent marginal leakage under cast restorations. 40 In the present case, the flowable composite Filtek Z350 XT was used to line the pulpal and axial walls of the tooth preparation prior to cementation of the restoration. ...

Influence of Cavity Lining on Marginal Leakage beneath Cast Restoration
  • Citing Article
  • December 2004

Nihon Hotetsu Shika Gakkai Zasshi

... The oral environment is subject to thermal stress and pH fluctuations from food and beverage consumption, which can impact the surface properties of resin materials, leading to long-term discoloration [13]. Over time, direct dental restorations, particularly resin composites, may exhibit surface wear and filler-matrix debonding, resulting in void formation [14]. In laboratory settings, the aging of dental material is typically evaluated through factors such as increased water sorption, surface roughness, and color changes, along with reduced strength and hardness [13,15]. ...

Effects of Thermal Cycling on Surface Texture of Restorative Composite Materials
  • Citing Article
  • June 2007

Dental Materials Journal

... Durch sehr unterschiedliche Wärmeausdehnungskoeffizienten von ZrO 2 (10x10 -6 K -1 ) und Komposit (25x10 -1 K -1 ) erzeugen thermische Wechsellasten größere Spannungen der Verbundflächen als zwischen Komposit und Metallen oder Silikatkeramiken mit geringeren Differenzen der WAK-Werte (zwischen 12-16x10 -1 K 1 )(Wegner et al. 2002). Die Verwendung von phosphatmonomerhaltigen Bondern oder Silanen mit Panavia F oder Rely X liefert auch nach künstlicher Alterung signifikant höhere Haftverbundwerte(Blatz et al. 2004;Murahara et al. 2007). Alleinige Oberflächenreinigung mit Isopropanol zur Erzeugung eines dauerhaften Haftverbundes mit MDP reicht nicht aus, sondern erfordert das zusätzliche Reinigen, Anrauen und Aktivieren der Oberfläche durch Sandstrahlung mit Al 2 O 3 (Wolfart et al. 2005; Quaas et al. 2007). ...

Bonding Durability of Commercially-available Luting Systems for Ceramic Restoration to Dental Zirconia
  • Citing Article
  • November 2007

Nihon Hotetsu Shika Gakkai Zasshi