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Maki SATO, Tomoko OHSHIMA, Nobuko MAEDA, Chikahiro OHKUBO
2013 Volume 32 Issue 3 Pages
355-360
Published: May 30, 2013
Released on J-STAGE: May 30, 2013
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The adherence of
Candida on dentures is related to diseases such as denture stomatitis and aspiration pneumonia. Mannan is a major component of the
Candida cell surface, and contributes to the cell adherence. A previous report indicated that the adherence of
C. albicans to culture dishes was inhibited by the coating them with mannan. The purpose of this study was to examine the adhesion inhibitory effect of mannan coating on acrylic denture surfaces against
C. albicans and
C. glabrata. The amount of
Candida attached on the acrylic surfaces coated with mannan was calibrated by culture methods. Mannan showed significant inhibitory effects on
Candida adhesion in both the yeast and hyphal form in a concentration-dependent manner, and the durability of the inhibitory effect continued for three days. These results suggest that mannan coating on the denture base acrylic can prevent
Candida adhesion on the denture.
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Hisako HIRAGUCHI, Masahiro KAKETANI, Hideharu HIROSE, Hisaji KIKUCHI, ...
2013 Volume 32 Issue 3 Pages
361-366
Published: May 30, 2013
Released on J-STAGE: May 30, 2013
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There is a concern that long-term immersion of impressions in disinfectant solutions may cause changes in the dimensions of the resulting stone casts. This study investigated the dimensional changes in stone casts resulting from immersion of five brands of addition-type silicone rubber impressions in disinfectant solutions for 30 min and 24 h. Impressions of a master cast designed to simulate an abutment tooth were immersed in 2% glutaraldehyde and 0.55% ortho-phthalaldehyde. The diameter of the stone cast was measured using a laser scan micrometer. For four brands of impression materials, 30-min immersion in disinfectant solutions produced no dimensional changes in the stone casts. For four brands of impression materials, 24-h immersion caused a significant decrease in the stone cast dimensions.
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Rukiye DURKAN, Elif Aydoğan AYAZ, Bora BAGIS, Ayhan GURBUZ, Nilgun OZT ...
2013 Volume 32 Issue 3 Pages
367-375
Published: May 30, 2013
Released on J-STAGE: May 30, 2013
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The purpose of this study was to evaluate the effect of denture cleansers on the surface roughness, hardness and color stability of two polyamides (Valpast, Deflex), a butadiene styrene copolymer PMMA (Rodex), and PMMA polymer as a control group (Paladent). Each material was divided into 5 sub-groups (
n=7) as two control and three test groups. Three test groups were immersed for 20 days in commercially available three denture cleansers (CO-Corega, PR-Protefix, VA-Valclean). Two-way analysis of variance and Tukey's
post hoc HSD test were used to evaluate surface roughness and hardness data (α=0.05). Δ
E, Δ
L*, Δ
a*and Δ
b* mean values were used for ANOVA, Tamhane test was used as
post hoc. Polyamides showed low hardness and high roughness before and after immersion. A significant decrease in hardness was observed for all resins except Rodex after immersion (
p<0.05). The denture cleansers changed the roughness, hardness and color of some resins.
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Kisaki SHIMAZU, Kiyokazu OGATA, Hiroyuki KARIBE
2013 Volume 32 Issue 3 Pages
376-380
Published: May 30, 2013
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This
in vitro study was undertaken to evaluate the caries-preventive effect of three orthodontic band cements (a dual-curing resinmodified glass ionomer cement [RMGIC] and two light-curing polyacid-modified composite resin [compomer] cements) in terms of fluoride release, retentiveness, and microleakage after thermocycling. The RMGIC (Ortholy Band Paste [GC Ortholy, Inc., Tokyo, Japan]) showed a significantly higher amount of cumulative fluoride release over 180 days (
p<0.001) and significantly greater tensile bond strength (
p<0.001) than the compomer cements (Transbond Plus [3M Unitek, Monrovia, CA, USA] and Ultra Band-Lok [Reliance Orthodontic Products, Inc., Itasca, IL, USA]). Its bond strength was unaffected by thermocycling (2,000 cycles), indicating good retentiveness, whereas that of the compomer cements significantly decreased after thermocycling. Moreover, it had lower dyepenetration scores, indicative of less microleakage. These findings suggest that the RMGIC may have a better caries-preventive effect than the compomer cements and is suitable for long-term orthodontic banding.
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Hidekazu OSADA, Hidemasa SHIMPO, Tohru HAYAKAWA, Chikahiro OHKUBO
2013 Volume 32 Issue 3 Pages
381-389
Published: May 30, 2013
Released on J-STAGE: May 30, 2013
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Thermoplastic resin clasps have been used for esthetic denture rehabilitation. However, details of the design of the clasps have never been thoroughly clarified. This study investigated the retentive forces of thermoplastic resin clasps for non-metal clasp dentures. The retentive forces of all thermoplastic resin clasps depended on the elastic modulus of each resin, undercuts, thickness, and widths of the tested. A clasp with more than 0.5 mm undercut and 1.0 mm thickness is needed for Valplast. Similarly, more than 0.25 mm undercut and 1.0 mm thickness and 0.5 mm undercut and 0.5 mm thickness are required for Estheshot and Reigning, respectively; thus, the recommended clasp arm thickness is 1.0 mm to 1.5 mm for Valplast and Estheshot and 0.5 mm to 1.0 mm for Reigning when the width of the retentive arm is 5.0 mm.
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Norio TAKASUSUKI, Yusuke IDA, Yukito HIROSE, Morio OCHI, Kazuhiko ENDO
2013 Volume 32 Issue 3 Pages
390-397
Published: May 30, 2013
Released on J-STAGE: May 30, 2013
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The corrosion and tarnish behaviors of two Au-based casting alloys (ISO type 1 and type 4 Au alloys) and their constituent pure metals, Au, Ag, Cu, Pt, and Pd in a polyvinylpyrrolidone-iodine solution were examined. The two Au alloys actively corroded, and the main anodic reaction for both was dissolution of Au as AuI
2−. The amount of Au released from the ISO type 1 Au alloy was significantly larger than that from the ISO type 4 Au alloy (
P<0.05). Visible light spectrophotometry revealed that the type 1 alloy exhibited higher susceptibility to tarnishing than the type 4 alloy. The corrosion forms of the two Au alloys were found to be completely different,
i.e., the type 1 alloy exhibited the corrosion attack over the entire exposed surface with a little irregularity whereas the type 4 alloy exhibited typical intergranular corrosion, which was caused by local cells produced by segregation of Pd and Pt.
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Ja-Uk GU, Nak-Sam CHOI
2013 Volume 32 Issue 3 Pages
398-404
Published: May 30, 2013
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In this study, a nondestructive method based on acoustic emission (AE) analysis was developed to evaluate the marginal failure states of dental composite restorations. Three types of ring-shaped substrates, which were modeled after a Class I cavity, were prepared from polymethyl methacrylate, stainless steel, and human molar teeth. A bonding agent and a composite resin were applied to the ring-shaped substrates and cured by light exposure. At each time-interval measurement, the tooth substrate presented a higher number of AE hits than polymethyl methacrylate and steel substrates. Marginal disintegration estimations derived from cumulative AE hits and cumulative AE energy parameters showed that a signification portion of marginal gap formation was alreadyrealized within 1 min at the initial light-curing stage. Estimation based on cumulative AE energy gave a higher level of marginal failure than that based on AE hits. It was concluded that the AE analysis method developed in this study was a viable approach in predicting the clinical survival of dental composite restorations efficiently within a short test period.
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Tokushi FUJIEDA, Mitsunori UNO, Hajime ISHIGAMI, Masakazu KURACHI, Hid ...
2013 Volume 32 Issue 3 Pages
405-408
Published: May 30, 2013
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The purpose of this study was to clarify the effect of silver nanoparticles on the behavior of subcritical crack growth (SCG) in dental porcelains. Prior to occurrence of fast fracture in dental porcelains, SCG occurs and leads to strength degradation over time. SCG in dental porcelains can be characterized by the stress corrosion susceptibility coefficient,
n. A higher
n value means a higher resistance to SCG. In this study, porcelain disks were prepared by mixing a commercial dental porcelain powder with different concentrations of silver nanoparticles, and then air-dried and fired according to manufacturer's instructions. Stress corrosion susceptibility coefficients of powder compacts were determined using a post-indentation method. A Vickers indenter was applied to the porcelain surface, and lengths of median cracks were measured at fixed time intervals over a 24-h period to calculate
n. Addition of silver nanoparticles significantly increased the stress corrosion susceptibility coefficient of dental porcelain.
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Nobuya KITAHARA, Kazuo ITOH, Mizuho KUSUNOKI, Misa OIKAWA, Takashi MIY ...
2013 Volume 32 Issue 3 Pages
409-412
Published: May 30, 2013
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The effectiveness of commercial and experimental silane coupling agents was evaluated by measuring their shear bond strengths to a ceramic disk. Experimental one-bottle silane coupling agents were prepared using 3-MPTS, 4-META, and resin monomers. The surfaces of two ceramic disks (IPS e-max, Ivoclar Vivadent AG, Schaan, Lichtenstein) were treated by a silane coupling agent to bond them to each other; this bonding was mediated by a commercial flowable resin composite (Clearfil Majesty LV, Kuraray, Tokyo, Japan). A commercial silane coupling agent (Clearfil Porcelain Bond Activator, Kuraray, Tokyo, Japan) modified by adding 4-META exhibited a significantly higher bond strength than the unmodified commercial one-bottle silane coupling agent. Among the tested materials, two experimental one-bottle silane coupling agents composed of 5% 4-META, 45% 3-MPTS, and 50% resin monomers exhibited statistically highest bond strengths.
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Noriko MUTOH, Takenori SATOH, Hirotaka WATABE, Nobuyuki TANI-ISHII
2013 Volume 32 Issue 3 Pages
413-419
Published: May 30, 2013
Released on J-STAGE: May 30, 2013
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We evaluated the biocompatibility of resin-based root canal sealers (RCSs) in the periapical tissues of rats. Wistar rats underwent tooth replantation for reproducing the response of periapical tissue with RCSs. The resin-based Epipany SE™, AH Plus Jet™, the eugenol-based sealer (Canals) and a control group were employed. The upper right first molar was extracted and applied with RCSs on apices, and then the tooth was repositioned. Histological evaluation demonstrated that mild inflammation occurred in the periapical tissue with Epiphany and AH Plus Jet sealers on day 7, whereas Canals induced severe-to-moderate inflammation. The statistical analyses demonstrated that the significant differences were observed between Canals and the other groups on day 7 regarding inflammatory response. On day 14, the lesions induced by all sealers were healed and replaced predominantly by fibrous connective tissue. Our results suggest that Epiphany SE and AH Plus Jet are good biocompatible materials.
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Yoshihiro NISHITANI, Keiichi HOSAKA, Tomohiro HOSHIKA, Masahiro YOSHIY ...
2013 Volume 32 Issue 3 Pages
420-424
Published: May 30, 2013
Released on J-STAGE: May 30, 2013
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It is known that chlorhexidine (CHX) does not inhibit micro-tensile bond strengths (MTBS) when it is used in etch-and-rinse adhesives. In that technique, CHX is applied to dentin as a primer after phosphoric acid-etching before bonding with Single Bond. It would be more convenient if it is possible to incorporate CHX into the adhesive. The purpose of this study was to compare the MTBS and the FT-IR percent conversion of an all-in-one self-etching adhesives contained varying concentration of CHX. Extracted human third molars were bonded with a control all-in-one adhesive or experimental versions containing 0.5, 1, 2 or 5% CHX. The MTBS and the percent conversion of experimental adhesives containing up to 1% CHX were not significantly CHX-free control adhesives. However, addition of 2 or especially 5% CHX experimental adhesives produced significant reductions in both the MTBS and the percent conversion.
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Satoru MATSUNAGA, Hiroyoshi NAITO, Yuichi TAMATSU, Naoki TAKANO, Shini ...
2013 Volume 32 Issue 3 Pages
425-432
Published: May 30, 2013
Released on J-STAGE: May 30, 2013
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The aim of this study was to clarify the influence of shear modulus on the analytical accuracy in peri-implant jaw bone simulation. A 3D finite element (FE) model was prepared based on micro-CT data obtained from images of a jawbone containing implants. A precise model that closely reproduced the trabecular architecture, and equivalent models that gave shear modulus values taking the trabecular architecture into account, were prepared. Displacement norms during loading were calculated, and the displacement error was evaluated. The model that gave shear modulus values taking the trabecular architecture into account showed an analytical error of around 10-20% in the cancellous bone region, while in the model that used incorrect shear modulus, the analytical error exceeded 40% in certain regions. The shear modulus should be evaluated precisely in addition to the Young modulus when considering the mechanics of peri-implant trabecular bone structure.
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Kenji SAKOGUCHI, Hiroyuki MINAMI, Shiro SUZUKI, Takuo TANAKA
2013 Volume 32 Issue 3 Pages
433-440
Published: May 30, 2013
Released on J-STAGE: May 30, 2013
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This study evaluated the effect of abutment materials on the fracture resistance of composite crowns for premolars. Composite crowns were fabricated using two different indirect composite resin materials (Meta Color Prime Art or Estenia C&B) and cemented onto either a metal (Castwell M.C. 12) or composite resin (Build-It FR and FibreKor) abutment with resin cement (Panavia F2.0). Twenty-four specimens were fabricated for four groups (
n=6 each) and subjected to 280-N cyclic impact loading at 1.0 Hz. The number of cycles which caused the composite crown to fracture was defined as its fracture resistance. All data were statistically analyzed using ANOVA and the Bonferroni test (α=0.05). Composite crowns cemented onto resin abutments showed higher fracture resistance than those cemented onto metal abutments.
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Bogna STAWARCZYK, Christine KEUL, Florian BEUER, Malgorzata ROOS, Patr ...
2013 Volume 32 Issue 3 Pages
441-448
Published: May 30, 2013
Released on J-STAGE: May 30, 2013
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This study tested tensile bond strength (TBS) between veneering resins and polyetheretherketone (PEEK) after pre-treatment with adhesive systems. Five-hundred-seventy-six PEEK disks were fabricated, air-abraded and divided into six pre-treatment groups (
n=96/group): Z-Prime Plus, Ambarino P60, Monobond Plus, Visio.link, Signum PEEK Bond, and control group without pre-treatment. Each group was divided into three subgroups of different veneering resins (
n=32): Sinfony, GC Gradia and VITA VM LC. After specimen preparation with a bond area of 6.6 mm
2, half of each subgroup (
n=16) was tested initially, and the other half was thermo-cycled. TBS measurements were analysed by three-way and one-way ANOVA,
t-test and Weibull statistics. Groups without pre-treatment and groups pre-treated by Z-Prime Plus and Ambarino P60 showed no TBS. Pre-treatment with Monobond Plus increased the TBS values. The highest TBS before and after thermo-cycling between PEEK and all tested veneering resins was observed for groups pre-treated with Visio.link and Signum PEEK Bond.
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Daisaku SHIOMUKI, Hiroyuki MINAMI, Takuo TANAKA, Shiro SUZUKI
2013 Volume 32 Issue 3 Pages
449-455
Published: May 30, 2013
Released on J-STAGE: May 30, 2013
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This study evaluated, by measuring Vickers hardness (Hv), the effects of these factors on the degree of polymerization of dual-cure cement (Panavia F2.0) placed under a restoration: light transmission property of restoratives materials, distance from the directly irradiated surface, and elapsed time after light irradiation. Two materials were used for the restoration: silver-palladium-copper-gold alloy (Alloy)
versus zirconia (ZR). Restorations were cemented on bovine enamel by dual-cure cement. At 30 min, 2 h, 6 h, 1 day, and 1 week after definitive irradiation, Hv values at the enamel side of cement were evaluated at three measuring points: two points at the left and right margins and one point at the center. Data were analyzed by two-way ANOVA with Bonferroni correction (α=0.05). With the Alloy restoration, Hv value at the center was significantly lower than those at the margins at 30 min after irradiation. For both Alloy and ZR restorations, Hv value at each measuring point continued to increase significantly up to 6 h.
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Hajime ENDO, Ryo KAWAMOTO, Fuminori TAKAHASHI, Hirotaka TAKENAKA, Fumi ...
2013 Volume 32 Issue 3 Pages
456-461
Published: May 30, 2013
Released on J-STAGE: May 30, 2013
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This study evaluated the effect of a calcium phosphate desensitizer on the demineralization of bovine dentin by measuring changes in transmitted ultrasonic velocity. Bovine dentin specimens with and without application of desensitizer were immersed in 0.1 M lactic-acid buffer solution (pH 4.75) 10 min twice daily throughout the test period, and stored in artificial saliva solution (pH 7.0) between treatments. The propagation time of longitudinal ultrasonic waves was measured by a pulser-receiver. Data were evaluated using one-way ANOVA followed by Tukey HSD test (α=0.05). The ultrasonic velocity decreased over time in specimens stored in demineralizing solution (3,785-3,462 m/s); however, desensitizer-applied specimens had a significantly higher sonic velocity (3,945-3,990 m/s) than those without application. The calcium phosphate desensitizer appeared to reduce the demineralization of dentin and occluded dentinal tubules.
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Mayu HIDA, Ken MIYAZAWA, Shozo TSURUTA, Masahiro KUROSAWA, Yuki HATA, ...
2013 Volume 32 Issue 3 Pages
462-467
Published: May 30, 2013
Released on J-STAGE: May 30, 2013
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β-titanium alloy is frequently used in nickel-free orthodontic wires for patients with a metal allergy. However, the Young's modulus of β-titanium alloy wires is lower than that of Co-Cr-Ni alloys, causing loss of anchorage and failure to prevent unwanted tooth movements. To improve its mechanical properties for use in anchorage appliances such as transpalatal arches, Ti-6Mo-4Sn alloy wire was heat-treated at 300, 400, 500 and 600°C for 5 min, 30 min, and 4 h in this study. Tensile testing revealed that the wire heated at 500°C/30 min had a Young's modulus of 75 GPa and a tensile strength of 1,650 MPa —the highest among all the heat treatment groups. Therefore, Ti-6Mo-4Sn alloy wire heat-treated at 500°C/30 min yielded mechanical properties approximating those of wires currently used for retainers and transpalatal arches.
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Andaç Barkın BAVBEK, Erhan DEMIR, Barış GOKTAS, Betül OZCOPUR, Benin ...
2013 Volume 32 Issue 3 Pages
468-475
Published: May 30, 2013
Released on J-STAGE: May 30, 2013
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This study tested whether exhaled humid conditions would affect the adhesion of etch-and-rinse, two-step and one-step self-etch adhesive resins to enamel. Enamel surfaces of human maxillary anterior teeth (
N=240,
n=20) were exposed to four humid conditions (H1: 63-68%, H2: 73-78%, H3: 93-98%, H4: 36-45% RH) during bonding with Adper Single Bond 2 (SB2), Clearfil SE Bond (CSE) and Adper Easy Bond (AEB). Specimens were stored in distilled water at 37ºC for 24 h and tested to failure using micro-shear bond strength (μSBS) test. Data were analyzed using two-way ANOVA and Tukey's test (
p<0.05). The μSBS to enamel with SB2, CSE and AEB was not significantly affected by humidity parameters. AEB resulted in significantly lower μSBS in all conditions. The frequency of adhesive failures was the highest at H2, H3 for SB2, H3 for CSE and H1-4 for AEB indicating that humidity conditions may decrease adhesion quality to enamel.
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Jie LIN, Minglei SUN, Zhiqiang ZHENG, Akikazu SHINYA, Jianmin HAN, Hon ...
2013 Volume 32 Issue 3 Pages
476-483
Published: May 31, 2013
Released on J-STAGE: May 30, 2013
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The objective of this study was to assess and compare the flexural strength and Vickers hardness of five nanofiller-containing composites (Filtek Supreme XT, Gradia Forte, Luna-Wing, GNH400N, GCUC) against five microhybrid composites (Meta Color Prime Art, Solidex, Estenia C&B, Ceramage, Clearfil Majesty) before and after rotating fatigue test (RFT). For each resin composite, 16 rectangular beam specimens (2 mm×2 mm×25 mm) were prepared and half of which were subjected to 1×10
4 cycles in RFT. Flexural strength was determined using a three-point bending test. Vickers hardness measurements were carried out on specimens which failed after the three-point bending test. When under the influence of rotating fatigue, the flexural strength of all composites was affected by multiple factors. In contrast, rotating fatigue had no significant influence on the Vickers hardness of both microhybrid and nanofiller-containing composites.
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Ying ZHANG, Yong WANG
2013 Volume 32 Issue 3 Pages
484-491
Published: May 30, 2013
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The study investigated the influence of reactive (enamel) and un-reactive (glass) substrates on photo-polymerization of self-etching adhesives. Two commercial adhesives Adper Prompt L-Pop (APLP, pH~0.8) and Adper Easy Bond (AEB, pH~2.5) were applied onto prepared enamel and glass substrates using the same protocol. Micro-Raman spectroscopy was employed to determine the degree of conversion (DC) and the involved mechanism. DC of APLP was dramatically enhanced from ~9.4% to ~82.0% as when changing from glass to enamel, while DC of AEB on both substrates showed no difference. The DC distributions along the adhesive layers of the APLP and AEB on enamel showed descending and constant trends, respectively. Spectral analysis disclosed that the difference in chemical reaction of the two adhesives with enamel might be associated with the results. The chemical reaction of the adhesives with enamel significantly improved the DC of the strong APLP, but not that of the mild AEB.
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Nora BÄHR, Christine KEUL, Daniel EDELHOFF, Marlis EICHBERGER, Malgorz ...
2013 Volume 32 Issue 3 Pages
492-501
Published: May 30, 2013
Released on J-STAGE: May 30, 2013
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This study tested the impact of different adhesives and resin composite cements on shear bond strength (SBS) to polymethyl methacrylate (PMMA)- and composite-based CAD/CAM materials. SBS specimens were fabricated and divided into five main groups (
n=30/group) subject to conditioning: 1. Monobond Plus/Heliobond (MH), 2. Visio.link (VL), 3. Ambarino P60 (AM), 4. exp. VP connect (VP), and 5. no conditioning-control group (CG). All cemented specimens using a. Clearfil SA Cement and b. Variolink II were stored in distilled water for 24 h at 37°C. Additionally, one half of the specimens were thermocycled for 5,000 cycles (5°C/55°C, dwell time 20 s). SBS was measured; data were analyzed using descriptive statistics, four- and one-way ANOVA, unpaired two-sample
t-test and Chi
2-test. CAD/CAM materials without additional adhesives showed no bond to resin composite cements. Highest SBS showed VL with Variolink II on composite-based material, before and after thermocycling.
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Ji-Young BAE, Kenzo ASAOKA
2013 Volume 32 Issue 3 Pages
502-507
Published: May 30, 2013
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A numerical simulation model, which was based on the setting and heating reactions of the binder phase of phosphate-bonded investment compacts, was developed to compute the porosities of set and burnout compacts. Densities and concentrations of microsilica particles in dilute suspension were measured and input into the simulation model. Validity of the model was confirmed by experimental results, that is, colloidal silica suspensions were prepared using different silica concentrations and mixed with investment powders. Porosities of these set and burnout compacts were experimentally measured. Effects of these factors on the porosity of compacts were examined using the developed simulation model: liquid/powder (L/P) ratio, concentration of microsilica particles in colloidal silica suspension, and ratio of binder component (NH
4H
2PO
4) in investment powder. It was concluded that numerical simulation is a viable tool for dental materials research.
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Juro WADACHI, Masayuki SATO, Yoshimasa IGARASHI
2013 Volume 32 Issue 3 Pages
508-511
Published: May 30, 2013
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Dentures made of 2 different types of injection-molded thermoplastic resins (polyamide resin and polyester resin) and a denture made of conventional heat-polymerized resin were used to create an experimental model of a mandibular molar region with a two-tooth gap. In the experimental model, a force of 100 N was applied onto the mesial fossa of the first molars of the dentures, and comparisons were performed by measuring the pressure applied under the denture base and the subsidence rate of the denture. The polyamide resin denture showed the highest subsidence, exerted the highest pressure on the underlying mucosa, and showed significant differences with the other types of dentures. The findings showed that polyamide resins have the lowest degree of elasticity, and that when resins with such low elasticities are used in the denture base, they should preferably be reinforced with metals.
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Xiao xian CHEN, Xing gang LIU
2013 Volume 32 Issue 3 Pages
512-518
Published: May 30, 2013
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The purpose was to compare the retention and caries preventive effect of Fuji VII and a resin-based sealant in children at high risk (HR) and low risk (LR) of caries. Fifty-seven schoolchildren (150 teeth) with completely erupted bilateral permanent first molars were included. The study was a split-mouth, randomized trial. Sealant retention and caries were evaluated after 6 months, 1 year and 2 years. After 2 years, there was no statistically significantdifference in the incidence of caries between Fuji VII and Concise in the HR and LR groups. With Concise, LR children were less likely to have dental caries than HR. With Fuji VII, there was no difference in caries incidence between LR and HR. Retention of Concise was superior to that of Fuji VII. Our results suggest that Fuji VII and Concise sealants had similar caries preventive effects in children at high and low risk of caries.
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Dawasaz Ali AZHAR, Sadatullah SYED, Master LUQMAN, Assiry A ALI
2013 Volume 32 Issue 3 Pages
519-521
Published: May 30, 2013
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Methyl methacrylate (MMA) monomer, a primary component of dental resins, is known to induce cytotoxicity, dermatitis, and neuropathy. The objective of this study was to assess the incidence of micronuclei (MN) in buccal mucosal cells of dental technicians exposed to MMA using Buccal Micronucleus Cytome (BMCyt) assay. The Risk Group (RG=13) consisted of all the technicians working in the prosthetic production laboratory of KKU-College of Dentistry. The Control Group (CG=14) consisted of healthy students and doctors matching the age of RG subjects. Buccal mucosa scrapes obtained from all the 27 RG and CG subjects were stained with Papanicolaou stain and observed under oil immersion lens (100×) for the presence of MN. There were no significant differences in the incidence of MN between RG and CG (
p>0.05).
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