Purpose: The shape of the head and bristles of manual toothbrushes affect the efficacy of plaque removal. The purpose of this study was to investigate the plaque removal efficiency and usability of a dome-shaped bristled toothbrush, in comparison with a standard one. Methods: Twenty patients with chronic periodontitis (9 males and 11 females, mean age 59.1) and 20 volunteer dentists who had healthy periodontium (9 males and 11 females, mean age 28.1) at the Tokyo Medical and Dental University Hospital, Faculty of Dentistry participated in the study. The subjects were asked not to perform oral hygiene for 24 hours before the experiment to allow plaque to accumulate. Dome-shaped or flat (standard) bristled toothbrushes were randomly given to the subjects with periodontitis and volunteer dentists respectively, and they were then asked to perform tooth brushing for 3 minutes. The levels of plaque present before and after brushing were recorded using the modified plaque control record developed by O'Leary, and the rate of plaque removal was calculated. Patients with periodontitis were given professional instruction on how to use the toothbrush, and two more examinations were performed, after 2 weeks and after 4 weeks. Results: The plaque accumulation rate was significantly reduced after brushing with either the dome-shaped or flat bristled toothbrushes. Dentists who used the dome-shaped bristled toothbrush showed a higher rate of plaque removal compared to the other groups, though there was no significant difference (dentists who used dome-shaped toothbrush 62.4%, dentists who used flat-shaped toothbrush 48.7%, patients who used dome-shaped toothbrush 40.0 %, patients who used flat-shaped toothbrush 40.6%). Among the dentists, the dome-shaped bristled toothbrush showed significantly higher plaque removal efficiency, especially on the buccal sites of maxillomandibular anterior teeth and lingual sites of mandibular molars. Plaque removal rates of patients with periodontitis at each examination were 40.0%, 44.7%, and 45.9% in the dome-shaped bristled toothbrush group, and 40.6 %, 45.6%, and 41.2% in the flat bristled toothbrush group respectively, and there were no significant differences. From the results of a questionnaire using the Visual Analog Scale, patients showed a high level of satisfaction with using either the dome-shaped or flat bristled toothbrush. Conclusion: The dome-shaped bristled toothbrush showed as high plaque removal efficiency as the standard flat bristled toothbrush, and showed higher plaque removal efficiency for persons having knowledge of oral hygiene.

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Purpose: The maintenance of dental implants is essential for a successful outcome. However, few studies have examined damage to the implant surface caused by hand instrumentation. This study evaluated morphological changes on titanium alloy surfaces treated with different types of hand instruments. Methods: Titanium alloy surfaces were polished and test areas (3×3 mm) were painted with a waterproof pen. Stainless steel (Stn), titanium (Ti), and poly phenylene sulfide resin (PPS) scalers were used to remove the paint. The average roughness (Ra) of each treated titanium surface was measured using a profilometer. Morphological changes were examined by scanning electron microscopy. The time required to remove all paint was also measured. Analysis of variance and Tukey's honestly significant difference test were used to analyze the data (α=0.05). Results: The Stn scaler markedly damaged the titanium surface, whereas the Ti and PPS scalers did not. The Ra value was significantly higher with the Stn scaler than with the Ti and PPS scalers. No significant difference was observed between the Ti and PPS scalers. Removal time was significantly shorter when the Stn scaler was used. Conclusion: All instruments tested increased the roughness of the polished titanium surface, but the Stn scaler caused more damage than the other scalers. Understanding the characteristics of instruments and their use is important for implant maintenance therapy.

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Purpose: It is important to maintain gingival health, which is directly influenced by periodontal disease pathogenesis, in order to prevent the development and progression of periodontal disease. There have been several reports on the effect of gingival massage. Isotropic high-density carbon has high far-infrared radiation efficiency, and is expected to be useful for various medical devices. However, there has been no report on the influence of isotropic high-density carbon on the gums. In the present study, we investigated the effect of a carbon roller made from isotropic high-density carbon on a normal human gingival fibroblast cell line (Gin-1). Methods: A carbon roller was used as a heating (37 or 42℃) and vibrating massage roller (Gum-roller, Ohgi Technological Creation). Isotropic high-density carbon (carbon ball) was used at the tip of the roller. Gin-1 was cultured in 10% FBS in DMEM. A carbon ball group, carbon ball+heating (37 or 42℃)+vibrating group, and control group (no stimulation by carbon roller) were fabricated to evaluate the effect of the carbon roller. Consequently, FGF-2, NGF, VEGF, and EGF were produced using real-time PCR and ELISA, and cell activity was evaluated by a WST assay and morphological changes were examined by microscope using Giemsa staining. Results: FGF-2 mRNA expression of Gin-1 significantly increased in the carbon roller+heating (37℃)+vibrating group compared with the control group. VEGF and EGFmRNA were not detected. FGF-2 protein production by Gin-1 also increased in the carbon roller+heating+vibrating group. Conclusion: The results suggest that the carbon roller used in the present study increased FGF-2 production by gingival fibroblasts, and contributed to the improvement of gingival wound healing.

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Purpose: Many studies have been conducted to examine the bond strength of bonding agents to dentin using shear and tensile bond strength measurements. However, the fracture patterns in these bond strength tests showed different failure modes, such as adhesional failure between the bonding agent and the dentin, cohesional failure within the dentin and resin composite, and mixed failure modes. Therefore, these bond strength tests did not solely reflect adhesional failure between the bonding agent and dentin. In this study, a scratch tester was used to examine the thin-film bond strength between the bonding agent and human dentin, and the characteristics and accuracy of measurement were clarified. Methods: Four one-step bonding agents were investigated: BeautiBond, Bond Force, Adper Easy Bond, and Clearfil tri-S Bond. The relationship between the thin-film bond strength (by scratch test) and the tensile bond strength of the bonding agents was evaluated. In addition, the influence of the contact angle to the dentin surface and the surface tension of the bonding agents on the thin-film bond strength were evaluated. Results: As a result, the thin-film bond strength of the bonding agent (Clearfil tri-S Bond) on various film thicknesses ranged from 5.29 to 8.50 N, meaning that the strengths of the bonding agents were significantly influenced by the film thickness. The thin-film bond strength of the four bonding agents ranged from 5.63 to 7.19 N and the standard deviation (SD) was less than 1.00 N. The tensile bond strength of the bonding agents ranged from 6.27 to 15.59 MPa and the SD ranged from 1.95 to 4.49 MPa. The recurrence coefficients showed a significant correlation (r=0.82) between the thin-film bond strength and the tensile bond strength of the bonding agents. The measured contact angle on the dentin surface of the bonding agents decreased with time, and water, ethanol, and acetone as solvents of the bonding agents showed the same trend. The contact angle of each bonding agent was approximately related to that of the solvent. The measured surface tension of the bonding agents, water, ethanol, and acetone did not change with time. The recurrence coefficients did not show a significant correlation between the thin-film bond strength and the contact angle or the surface tension. Conclusion: These results suggest that the thin-film bond strength test was successful in testing the bonding agent's ability to bond to dentin surfaces. The contact angle and surface tension were influenced by dilution in water, ethanol, and acetone solvents, however, the wettability of the bonding agents to dentin did not influence the thin-film bond strength.

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Purpose: The purpose of this study was to evaluate penetration of self-etching primer to human sound dentin using confocal laser scanning microscope (CLSM) with fluorescent dye. Methods: The fluorescent dye Rhodamine B was mixed into self-etching primer of Clearfil Mega Bond FA (Kuraray Noritake Dental) at the concentration of 0, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1%, or 0.2%. All dentin surfaces were treated with Clearfil Mega Bond FA. Resin composites (Clearfil AP-X) were built up incrementally according to the manufacturer's instruction. 64 specimens were subjected to the observation of the interface of resin and dentin with CLSM and SEM. The 32 specimens were then serially sectioned into multiple sliced parts and then micro-tensile bond strength (MTBS) was measured in a universal testing machine. Results: Penetration of monomer into dentin via dentinal tubules was observed as moderate in the group of 0.07, 0.08, 0.09% and 0.1%. On the other hand, in the group of 0.2%, the color of Rhodamine B was too dark to identify the details of the dentinal tubules. There was no significant difference in the MTBS between the group of 0.05, 0.06 or 0.07% and control (p>0.05). The MTBS produced by the group 0.08, 0.09, 0.1% or 0.2% were significantly different from control (p<0.05). Conclusion: This study suggested that the application of CLSM was effective to evaluate penetration of self-etching primer to dentin. A high concentration of Rhodamine B influenced the bond strength. It was suggested that the appropriate concentration of Rhodamine B was 0.07% in the Mega Bond FA Primer.

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Purpose: The purpose of this study was to evaluate the effects of low-intensity pulsed ultrasound (LIPUS) on bone formation induced by polylactate-polyglycolate-copolymer/gelatin sponge complexes (PGS) containing recombinant human bone morphogenetic protein-2 (rhBMP-2) at palatal subperiosteal sites (n=24) in 15-week-old male Wistar rats. Methods: RhBMP-2/PGS (1.0 μg/μl) was implanted into the palatal subperiosteal site and treated with LIPUS (1.0 MHz, 240 mW, 5 min) every 3 days (LI-BMP group) or without LIPUS (BMP group). In addition, rhBMP-2/PGS (1.0 μg/μl) was not implanted and rats were treated with LIPUS (LI group) or were not treated with LIPUS (Cont group). Animals were euthanized 3 weeks after surgery. Results: Thickness of new bone in LI-BMP and BMP groups was significantly higher when compared with LI and Cont groups (p<0.05). There were no significant differences in thickness of new bone between LI-BMP and BMP groups (p>0.05). Newly formed bone in the BMP group was continuous with the original bone. On the other hand, newly formed bone was largely integrated with the original bone in the LI-BMP group. Conclusion: These results suggest that LIPUS has the ability to enhance maturation of bone induced by rhBMP-2 in the case of palatal subperiosteal implantation in adult rats.

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Purpose: The purpose of this study was to monitor the main periodontopathic bacteria during the treatment of periodontal diseases and to re-evaluate the effectiveness of monitoring of bacteria. Methods: Sixteen patients (6 males and 10 females, mean age 40.6) with chronic periodontitis (CP) or aggressive periodontitis (AP) participated in this study. Probing pocket depth, clinical attachment level, bleeding on probing, Plaque Index, and suppuration of all existing teeth were undertaken for each patient. One deep pocket site (DS, PD &ge;4 mm) and one shallow pocket site (CS as control, PD<3 mm) were chosen in each patient. Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), Treponema denticola (Td) and Aggregatibacter actinomycetemcomitans (Aa) were detected in each subgingival pocket by means of the real-time PCR method. Clinical measurements and the bacterial examination were done in the baseline, before scaling and root planning (SRP), and one month and two months after SRP. Results: Seven CP and nine AP patients were examined. Of these, 7 patients completed all the examinations. At the baseline, the distribution of bacteria, except Aa, tended to be higher in the deep pocket sites of CP than in AP In CS, bacteria tended to be high when Plaque Index ≥1. Aa was only found in 1 AP patient. Pg and Tf tended to be detected even in shallow pockets and persistently existed after SRP, particularly when Pl I was higher. However, Td was detected only in deep pockets and rapidly disappeared after SRP. In addition, Pg and Tf tended to recover faster in the patients with poor oral hygiene. In the patients treated by full mouth-SRP in conjunction with systemic antimicrobial therapy, all examined bacteria became negative 2 months after SRP. Conclusion: The examination and monitoring of periodontopathic bacteria seemed to be effective to diagnose periodontal diseases and to make and re-evaluate treatment plans.

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Purpose: The Nd: YAG laser has been widely used for periodontal pocket irradiation. In a lot of cases, the bottom of the periodontal pocket was close to the alveolar bone. The purpose of this study was to investigate the morphological effect of Nd: YAG laser irradiation on the MC3T3-E1 cell by different Nd: YAG laser irradiation settings. Methods: MC3T3-E1 cells were cultured with 10% FBS α-MEM medium and were irradiated using the Nd: YAG laser. The parameters in laser delivery were 3 groups; control, 100 mJ×30 pps×10 seconds and 200 mJ×30 pps×10 seconds. Following irradiation, cells were cultured for 24 hours. The cell number and migration assay were measured. The cell cultures were analyzed by morphological examination under a phase-contrast microscope and scanning electron microscope (SEM). Results: The number of 100 mJ×30 pps×10 seconds was significantly increased (p<0.001) ; however, 200 mJ×30 pps×10 seconds was significantly decreased (p<0.001) compared with control. It was detected that the cell migration ability of 200 mJ×30 pps×10 seconds was significantly decreased compared with control and 100 mJ×30 pps×10 seconds. A significant decrease in cell numbers was detected in 200 mJ×30 pps×10 seconds (p<0.05). We observed the cellular damage of cultured MC3T3-E1 induced by Nd: YAG laser irradiation, comparable with control by SEM. However the damage could not be detected by phase-contrast microscope. Conclusion: Our study demonstrated the cell damaging effects of the Nd: YAG laser with high power irradiation. It was shown that the difference of laser irradiation settings makes the cell function worse. It proved that dentists need to understand the potential hazard of laser application in periodontal treatment.

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Purpose: Periodontopathic bacteria and inflammation in a residual periodontal pocket after periodontal therapy increase the risk for further progression of periodontitis. A tooth cleaning gel containing antibacterial and anti-inflammatory agents would be effective to inhibit such progression. The tooth cleaning gel 'Jellcoat F' contains 0.05% chlorhexidine hydrochloride as an antibacterial and β-glycyrrhetinic acid as an anti-inflammatory. We evaluated the effects of Jellcoat F on residual periodontal pockets with clinical, microbiological and biochemical analyses. Methods: The present study had a randomized, controlled, double-blinded design. Systemically healthy patients with &ge;20 teeth were enrolled if they had at least two teeth with residual pockets of 6-7 mm depth after at least a month from the completion of active periodontal therapy containing scaling and root planing. Twenty patients were randomly assigned to the test group who used Jellcoat F or the control group who used placebo. Gingival index (GI), plaque index (Pl I), probing pocket depth and bleeding on probing were recorded. In each patient, gingival crevicular fluid (GCF) was collected from one of the teeth with residual pockets, and subgingival plaque from the other. The levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in GCF and Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia and Treponema denticola in subgingival plaque were determined. After the collections, residual pockets were filled with Jellcoat F or placebo. Patients were instructed to brush their teeth with Jellcoat F or placebo and also apply the gel with a retainer for 10 minutes before sleeping. After 4 weeks, the same examinations were performed. Results: No adverse event was observed. At the baseline, no difference was observed between the test and control groups in age, sex, number of teeth, levels of periodontopathic bacteria, AST and ALT. Comparing the baseline and 4 weeks, only GI and Pl I were significantly decreased in the test group. No other change was found in both test and control groups. Changes of measurements during the 4 weeks were not statistically different between the groups. The effect of Jellcoat F to improve GI remained significant after being adjusted for age and sex. Conclusion: Application of Jellcoat F for 4 weeks on residual pockets after periodontal therapy with teeth brushing and a retainer did not significantly change the levels of periodontopathic bacteria in subgingival plaque, AST and ALT in GCF However, it might suggest the reduction of clinically evaluated supragingival plaque and gingival inflammation.

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Purpose: The purpose of the present study was to evaluate the antibacterial properties and the morphological change in oral bacteria by catechin powdered green tea (catechin). Method: Streptococcus mutans and Streptococcus sanguinis were used in this study. Both bacterial strains were inoculated in Trypticase Soy Broth containing 0.5 % yeast extract (TSBY) and adding catechin (1.9, 1.0, 0.75, 0.5 and 0.25 g/l), cultured at 37℃ for 48 hours anaerobically, and measured for minimal inhibitory concentration (MIC). In addition, each bacterial strain was dropped into 1.9 g/l solution; the morphological changes of each bacterium after 1 and 3 hours were observed under SEM and TEM with negative staining to ascertain the influence on oral bacteria of catechin. Results: Neither bacterial strains were grown with the 1.9 g/l culture medium. The MICs were found to be 1.9 g/l against S. mutans and 0.25 g/l against S. sanguinis. In the presence of catechin, the number of bacterial strains was decreased after 1 and 3 hours. Judging from the SEM and the TEM of both bacterial morphology, the bacterial strains appeared to reduce the number of bacterial cells and to change in form when dropped into 1.9 g/l solution. Conclusion: Catechin was found to have an antibacterial effect on oral bacteria. This finding suggests the usefulness of catechin for oral health care and the prevention of local and systemic disease.

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Purpose: The purpose of this study was to evaluate the mechanical properties and the bonding properties of resin cements on the assumption that a resin-retained bridge was bonded to enamel. A three points bending test was used to investigate the physical mechanical property of resin cements. Tensile bond strength (TBS) was measured after the retainer was bonded to enamel by the resin cements. The fractured surface was observed by SEM to analyze the failure mode. Materials and Methods: C & B MetaBond (CB) and Multibond II (MB) were employed as the MMA-based resin cement. Resicem (RC) was used as the composite resin cement. Self-adhesive resin cements used were RelyX TM Unicem Cliker (UC) and Clearfil SA Luting (SL) and Maxcem (MC). A metal retainer was fabricated from 12 %Au-Ag-Pd alloy. The facial surface of a bovine incisor was ground to prepare the enamel surface. The prepared enamel was either conditioned according to the manufacturer's instructions or etched with phosphoric acid for 15 seconds followed by the conditioning of the enamel. The metal retainer was adhered to the processed enamel with the resin cements. TBS was determined after storage in 37℃ water for 24 hours or 37℃ water for 24 hours followed by thermal cycles (TC). The fractured surface was observed with SEM. Results: The three points bending tests were 71.8 MPa for SB, 70.8 MPa for MB, 124.6 MPa for RC, 88.8 MPa for UC, 109.7 MPa for SL, and 84.0 MPa for MC. The TC load decreased TBS with SB, while phosphoric acid etching increased TBS with SL, MC and UC. Although there was little change in TBS with MB and RC, improved adhesion by phosphoric acid etching was suggested from the observation of the fracture surface. Conclusion: As for the resin cements of the self-adhesive type and self-etching primer type, pre-etching of enamel improved the bonding properties of resin cements. And the resin cement using the automatic mixing tip had lower degradation through the TC load than resin cement not using it.

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Purpose: There have been few reports about the inhibition of demineralization in pits and fissures with unique configurations. Surface pre-reacted glass-ionomer (S-PRG) filler can release several types of ions, mainly fluoride ion, and can therefore display anti-demineralization and remineralization effects. This study investigated the in vitro effects of S-PRG filler containing light-cured, resin-based sealants on the demineralization of the neighboring artificial enamel grooves. Methods: Enamel discs, 5 mm in diameter, from bovine incisors, were covered with dentin-bonding agent. Three grooves, 250 μm wide and 500 μm deep, perpendicular to the outer surface, were made with a diamond wire saw, with 1.0 mm distance between the groove margins. Each sealant was placed into the first groove at one end of each disc. Four sealants were tested (n=6 each): (1) CONT, Palfique Light Sealant, containing no fluoride; (2) TMT, Teethmate F-1_<2.0>, containing fluoride; (3) BTS, BeautiSealant, containing S-PRG filler; and (4) FL, Fuji III LC, a resin-modified, glass-ionomer-based sealant. The specimens with each sealant were immersed in a demineralization gel (0.1 mol/l lactic acid, pH 4.6) for 10 days at 37℃. Transverse microradiography was used to assess mineral content profiles and integrated mineral loss (IML: vol%×μm) in four regions: 1) the groove nearest the filled groove, designated Groove-1 (G1); 2) the farther as Groove-2 (G2); 3) the area near the orifice (O) of each groove; and 4) the 250 μm area below the O as the middle area (M). Statistical differences were analyzed by the Games-Howell and Mann-Whitney tests. Results: IML was significantly higher in the O than in the M area (p<0.05), except for BTS (G1) and FL (G1 and G2). This result reproduces the environment of a natural groove that retards the diffusion of hydrogen ion toward the bottoms of grooves. In G10, the IML of BTS was significantly less than that of CONT or TMT. The IML of FL showed the least among the test materials groups in all areas. Conclusion: BeautiSealant containing S-PRG filler had the anti-demineralization ability of artificial enamel grooves close to the material.

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Purpose: Surface characteristics and bacterial adhesion characteristics of tooth coating materials were investigated. Methods: In this study, using 2 types of tooth-coating material with different compositions and a 3-dimensional electron probe surface roughness analyzer, the surface roughness, gloss level, antibacterial activity against cariogenic Streptococcus mutans, and adhesion characteristics of Streptococcus oralis, which is the bacterium showing initial adhesion, were investigated. The 2 types of coating material were Beauty Coat (BC, main components: S-PRG fillers, bis-GMA, TEGDMA) and White Coat (WC, main components: silica fillers, sodium fluoride, UDMA, HEMA). Based on differences in the surface treatment method, the BC group was classified into the strip-pressure group (BCA), finishing-polishing group (BCP), and resin-hardening accelerator application group (BCG), and the WC group was classified into the strip-pressure group (WCA), finishing-polishing group (WCP), and surface-lubricant application group (WCT). Result: Although no significant differences in the surface roughness were noted between the 2 types of tooth-coating material in each surface treatment method, the gloss level significantly differed in the order of BCA, WCA>BCG, WCT>BCP, WCP. No influences of 1,000 times of thermal cycling in water at 4 and 60℃ were observed. Furthermore, although the 2 types of tooth-coating material showed no antibacterial activity against S. mutans in each surface treatment method, the adhesion characteristics of S. oralis was significantly lower in BCA and BCP, in comparison with other groups. From these results, it was speculated that the capacity for bacterial adhesion to tooth-coating materials, whose surface roughness (Ra) is less than 0.1 μm and gloss level is 40-90%, is not influenced by the surface roughness or gloss level, but is influenced by the composition of tooth-coating materials, such as S-PRG fillers and sodium fluoride, in particular. Conclusion: It was suggested that, although tooth-coating material application is a temporary treatment, the restoration surface becomes smoother and glossier with each surface treatment method, and the use of tooth-coating materials considering the bacterial adhesion characteristics will be beneficial to the prognosis after surface treatment from the perspectives of esthetics and oral hygiene.

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Objectives: Coenzyme Q10 (also called ubiquinone) is a key component of the mitochondrial respiratory chain for adenosine triphosphate synthesis. Coenzyme Q10 is recognized as an intracellular antioxidant that protects cellular components from free radical-induced oxidative damage. In nearly every tissue of the human body, coenzyme Q10 levels decline with age. Because of coenzyme Q10's ubiquitous role in the body, its decline is believed to play a role in aging and the pathogenesis of many degenerative or chronic diseases. In this study, we investigated the effect of reduced coenzyme Q10 supplementation on clinical parameters, VSC and salivary antioxidant capacity in patients with periodontitis. Material and methods: This randomized, double blind, placebo controlled parallel study involved 45 adult patients with untreated periodontitis who were randomly assigned to the placebo group (n=25) or the reduced coenzyme Q10-supplemented group (150 mg/d, n=20). Intervention was administered for 12 weeks. Clinical measurements were recorded and saliva was collected for the antioxidant capacity test. Salivary antioxidant capacity was also measured using a chemiluminescence reader based on the Fenton reaction in which antioxidants are trapped by luminol, resulting in light emission. Results: Plaque control was significantly decreased in the coenzyme Q10 group. Salivary antioxidant activity was significantly reduced in the control group at week 8, whereas that in the coenzyme Q10 group was unchanged. VSC was slightly reduced in the coenzyme Q10 group. Conclusion: Coenzyme Q10 supplementation could be beneficial for maintaining antioxidant capacity in patients with periodontitis.

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