担当区分：筆頭著者  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Antimicrobial mouthwash improves supragingival biofilm control when used in conjunction with mechanical removal as part of an oral hygiene routine. Mouthwash is intended to suppress bacterial adhesion during biofilm formation processes and is not aimed at mature biofilms. The most common evidence-based effects of mouthwash on the subgingival biofilm include the inhibition of biofilm accumulation and its anti-gingivitis property, followed by its cariostatic activities. There has been no significant change in the strength of the evidence over the last decade. A strategy for biofilm control that relies on the elimination of bacteria may cause a variety of side effects. The exposure of mature oral biofilms to mouthwash is associated with several possible adverse reactions, such as the emergence of resistant strains, the effects of the residual structure, enhanced pathogenicity following retarded penetration, and ecological changes to the microbiota. These concerns require further elucidation. This review aims to reconfirm the intended effects of mouthwash on oral biofilm control by summarizing systematic reviews from the last decade and to discuss the limitations of mouthwash and potential adverse reactions to its use. In the future, the strategy for oral biofilm control may shift to reducing the biofilm by detaching it or modulating its quality, rather than eliminating it, to preserve the benefits of the normal resident oral microflora.

DOI： 10.3390/antibiotics11060727

PubMed

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：MDPI  

The coronavirus disease pandemic has afforded dental professionals an opportunity to reconsider infection control during treatment. We investigated the efficacy of combining extraoral high-volume evacuators (eHVEs) with preprocedural mouth rinsing in reducing aerosol contamination by ultrasonic scalers. A double-masked, two-group, crossover randomized clinical trial was conducted over eight weeks. A total of 10 healthy subjects were divided into two groups; they received 0.5% povidone-iodine (PI), essential oil (EO), or water as preprocedural rinse. Aerosols produced during ultrasonic scaling were collected from the chest area (PC), dentist's mask, dentist's chest area (DC), bracket table, and assistant's area. Bacterial contamination was assessed using colony counting and adenosine triphosphate assays. With the eHVE 10 cm away from the mouth, bacterial contamination by aerosols was negligible. With the eHVE 20 cm away, more dental aerosols containing bacteria were detected at the DC and PC. Mouth rinsing decreased viable bacterial count by 31-38% (PI) and 22-33% (EO), compared with no rinsing. The eHVE prevents bacterial contamination when close to the patient's mouth. Preprocedural mouth rinsing can reduce bacterial contamination where the eHVE is positioned away from the mouth, depending on the procedure. Combining an eHVE with preprocedural mouth rinsing can reduce bacterial contamination in dental offices.

DOI： 10.3390/ijerph19106048

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PubMed

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：NATURE PORTFOLIO  

Silver diamine fluoride (SDF) has been long studied in laboratories, and its clinical effectiveness in the treatment and prevention of root caries has been reported. In the present study, we assessed the microbiological effects of SDF on dental biofilms grown on demineralized dentin in situ. Specifically, demineralized bovine root dentin slabs used as biofilm substrates were treated with 38% SDF, and the biofilms formed after this treatment were analyzed via real-time PCR, DEAD/LIVE cell staining, and SEM. Next, the viable cell count was determined, and microbial profiles were compared using 16S rRNA gene sequencing. Untreated slabs were used as controls. We observed significant decreases in viable cell counts (p < 0.05), number of biofilm-forming cells (p < 0.01), biofilm thickness (p < 0.01), and high proportion of dead cells with SDF treatment (p < 0.01). The microcolonies in the SDF-treated biofilms showed less complexity, and only a limited number of genera were differentially abundant between the groups. Microbial diversity index comparisons showed no significant differences between the groups with respect to treatments days (p = 0.362). Thus, SDF negatively influenced dental biofilm growth on demineralized root dentin in situ; however, its antimicrobial action did not target a specific oral taxon.

DOI： 10.1038/s41598-022-11477-1

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PubMed

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：MDPI  

We performed a comprehensive microbiome analysis of root caries lesions using 22 teeth extracted from patients with severe periodontitis. The carious lesions were mechanically collected and cryo-pulverized following tooth extraction. Differences in the microbiome were compared between independent lesions at the supragingival site (SG) and lesions extending beyond the gingival margin (GCB). DNA was extracted and the microbiome was characterized on the basis of the V3-V4 hypervariable region of the 16S rRNA gene using paired-end sequencing on an Illumina MiSeq device. The microbiota in root caries lesions showed compositionally distinct microbiota depending on the location. The most abundant OTUs in the SG group were Streptococcus (26.0%), Actinomyces (10.6%), and Prevotella (7.6%). GCB presented Prevotella (11.1%) as the most abundant genus, followed by Fusobacterium (9.6%) and Actinomyces (8.7%). The SG group showed a lack of uniformity in microbiota compared with the GCB group. The bacterial profiles of GCB varied considerably among patients, including periodontal pathogens such as Porphyromonas, Selenomonas, Filifactor, Peptococcus, and Tannerella. Periodontal pathogens inhabit root caries lesions that extend beyond the gingival margin. This study provides a new perspective for elucidating the microbial etiology of root caries.

DOI： 10.3390/microorganisms9112349

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PubMed

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：MDPI  

This study aimed to evaluate the anticariogenic biofilm activity of a novel zinc-containing glass ionomer cement, Caredyne Restore (CR), using a flow-cell system that reproduces Stephan responses. Streptococcus mutans biofilms were cultured on either CR or hydroxyapatite (HA) discs mounted on a modified Robbins device. The media were allowed to flow at a speed of 2 mL/min for 24 h while exposed to an acidic buffer twice for 30 min to mimic dietary uptake. Acid exposure enhanced biofilm inhibition in the CR group, which showed 2.6 log CFU/mm2 in viable cells and a 2 log copies/mL reduction in total cells compared to the untreated group after 24 h of incubation, suggesting enhanced anticariogenic activity due to the release of fluoride and zinc ions. However, there was no difference in the number of viable and total cells between the two experimental groups after 24 h of incubation in the absence of an acidic environment. The anticariogenic biofilm activity of CR occurs in acidic oral environments, for example in the transient pH drop following dietary uptake. CR restorations are recommended in patients at high risk of caries due to hyposalivation, difficulty brushing, and frequent sugar intake.

DOI： 10.3390/antibiotics10080977

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PubMed

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：MDPI AG  

Oral biofilms are associated with caries, periodontal diseases, and systemic diseases. Generally, antimicrobial therapy is used as the first line of treatment for infectious diseases; however, bacteria in biofilms eventually develop antibiotic resistance. This study aimed to apply our in situ biofilm model to verify whether an arginine preparation is useful for plaque control. Ten healthy subjects who did not show signs of caries, gingivitis, or periodontitis were recruited. The dental biofilms from the subjects were obtained using our oral device before and after gargling with arginine solution for 4 weeks. We found that 8% arginine solution significantly increased the concentration of ammonium ions (NH4+) in vitro and in vivo in saliva (p &lt; 0.05) and decreased the proportions of the genera Atopobium and Catonella in vivo. However, the viable count was unaffected by the mouthwash. Further, oral populations of the genera Streptococcus and Neisseria tended to increase with the use of arginine. Therefore, we concluded that using an 8% arginine solution decreased the NH4+ concentration in the oral cavity without affecting the number of viable bacteria, and that the diversity of oral bacterial flora changed. We suggest that arginine might help prevent mature biofilm formation.

DOI： 10.3390/pharmacy9010018

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PubMed

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：NATURE PORTFOLIO  

Dental biofilm present on the tooth surface is associated with oral diseases, such as dental caries and periodontal disease. Because bacterial numbers rapidly increase in saliva during sleep, oral care before sleeping is recommended for the prevention of chronic oral diseases. However, temporal circadian changes in the quantity and quality of dental biofilms are poorly understood. This study aimed to investigate the impacts of sleeping on dental biofilm amounts and compositions by using an in situ model. The use of this in situ model enabled us to investigate dental biofilm formed in the oral cavity and to perform a quantitative analysis. Subjects began wearing oral splints in the morning or before sleeping, and biofilm samples were collected at 8, 16, and 24 h after the subjects began wearing oral splints; these samples were then used in various experiments. No significant changes in the numbers of biofilm-forming bacteria were caused by sleep. However, the relative abundances of genera related to periodontitis (i.e., Fusobacterium and Prevotella) increased after awakening. In conclusion, the numbers of biofilm-forming bacteria were not affected by sleep, and the abundances of obligate anaerobes increased after sleep. This research may aid in defining efficacious preventive oral care.

DOI： 10.1038/s41598-020-80541-5

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PUBLIC LIBRARY SCIENCE  

Dysbiosis of the oral microbiome is associated with diseases such as periodontitis and dental caries. Because the bacterial counts in saliva increase markedly during sleep, it is broadly accepted that the mouth should be cleaned before sleep to help prevent these diseases. However, this practice does not consider oral biofilms, including the dental biofilm. This study aimed to investigate sleep-related changes in the microbiome of oral biofilms by using 16S rRNA gene sequence analysis. Two experimental schedules-post-sleep and pre-sleep biofilm collection-were applied to 10 healthy subjects. Subjects had their teeth and oral mucosa professionally cleaned 7 days and 24 h before sample collection. Samples were collected from several locations in the oral cavity: the buccal mucosa, hard palate, tongue dorsum, gingival mucosa, tooth surface, and saliva. Prevotella and Corynebacterium had higher relative abundance on awakening than before sleep in all locations of the oral cavity, whereas fluctuations in Rothia levels differed depending on location. The microbiome in different locations in the oral cavity is affected by sleep, and changes in the microbiome composition depend on characteristics of the surfaces on which oral biofilms form.

DOI： 10.1371/journal.pone.0259850

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記述言語：日本語   出版者・発行元：特定非営利活動法人 日本歯科保存学会  

<p> 目的 : 弾性係数が小さく, 形状記憶性, 超弾性, ファイルテーパーの多様化といった特徴をもつニッケルチタン (NiTi) 製ロータリーファイルは, ステンレススチールファイルと比較して高い切削効率や作業時間の短縮, 優れた根管追従性を有し現在の歯科臨床においても頻繁に用いられるようになりつつある. 本研究では, 歯学部学生の臨床前基礎実習において, FKGレイス (FKG Dentaire, Switzerland) およびJ型, S型湾曲根管模型を用いた根管形成実習を実施し, 習熟到達度を評価した.</p><p> 材料と方法 : 大阪大学歯学部3年生56名に対して, J型およびS型エポキシレジン製透明湾曲根管模型を用いてFKGレイスによる形成実習を2回ずつ行った. Kファイル#15にて穿通し, 根管長を測定後, プリレイスによる根管上部のフレアー形成とKファイル#15によるグライドパス形成を行った. 作業長は根管長から1mm引いた長さとし, レイス#30/6%, #30/4%, #25/4%, #20/4%を順に用いて, 最終拡大号数を#30/6%として根管形成を行った.</p><p> 形成前後の根管模型をマイクロCT (R_mCT2, RIGAKU) にて撮影し, 根管長軸方向に対して根尖から垂直に1, 2, 3, 4, 5mmおよび6mmの位置で内湾側および外湾側の根管幅径増加量を計測した. その後, S型根管幅径増加量および形成時間について, 学生ならびに日本歯科保存学会専門医・認定医10名がおのおの2回実施した結果を比較した.</p><p> 結果 : J型根管1回目の根管形成では, 62.5%の学生が根尖破壊, 5.4%がレッジ形成を生じ, 成功率は32.1%だった. J型根管2回目では, 30.4%が根尖破壊, 3.6%がファイル破折, 3.6%がレッジ形成を生じたものの, 成功率は62.4%と改善した. S型根管1回目は23.2%が根尖破壊, 7.1%がファイル破折を生じた. S型根管2回目では7.1%がファイル破折を生じた. 根管形成に要した時間については, 学生のS型2回目の形成時間がS型1回目と比較し有意に短縮され, 専門医・認定医によるS型1回目, 2回目の形成時間と比較して有意差を認めないレベルまで改善した. 内湾側および外湾側の根管幅径増加量については, 学生1回目, 2回目, ならびに専門医・認定医の間で統計学的有意差を認めなかった.</p><p> 結論 : NiTiファイルを用いた湾曲根管形成実習において, 特に根尖部の形成に注意して実習回数を重ねることにより, 難易度の高いS型湾曲根管であっても迅速に, 正確に根管形成ができるようになり, 習熟到達度が向上することが明らかとなった.</p>

DOI： 10.11471/shikahozon.62.263

CiNii Article

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記述言語：日本語   出版者・発行元：特定非営利活動法人 日本歯科保存学会  

<p> 目的 : ニッケルチタン (NiTi) ファイルは弾性係数が小さいため, 湾曲根管への追従性に優れており, 根管治療において必要不可欠な器材となりつつある. 本研究では, 歯学部学生の臨床前基礎実習において, FKGレイス (FKG DENTAIRE, Switzerland) による湾曲根管形成実習を実施し, 習熟到達度を評価した.</p><p> 材料と方法 : 大阪大学歯学部3年生49名に対して, J型エポキシレジン製透明湾曲根管模型を用いてFKGレイスによる形成実習を2回行った. Kファイル#15にて根管長を測定後, プリレイスによる根管上部のフレアー形成とKファイル#15によるグライドパス形成を行った. 作業長は根管長から1mm引いた長さとし, レイス#30/6%, #30/4%, #25/4%, #20/4%を用いて根管形成を行った.</p><p> 形成前後の根管模型をマイクロCT (R_mCT2, RIGAKU) にて撮影し, 根管長軸方向に対して平行に根尖から1, 2, 3, 5, 7, 10mmの位置で内湾側および外湾側の根管幅径増加量を計測した. 根管幅径増加量および形成時間を学生1回目, 2回目, ならびに日本歯科保存学会専門医・認定医10名の結果と比較検討した.</p><p> 結果 : 学生1回目の根管形成においては, 28根管で根尖破壊, 1根管でファイル破折, 1根管で目詰まりを認めた. また, 学生2回目の根管形成においては, 5根管で根尖破壊, 1根管で目詰まりを認めた. 内湾側および外湾側の根管幅径増加量および形成時間は, 学生1回目, 2回目, ならびに専門医・認定医の間で統計学的有意差を認めなかった.</p><p> 結論 : NiTiファイルを用いた湾曲根管形成実習において, 根尖部の形成に特に注意を促すことにより, 習熟到達度が向上することが明らかとなった.</p>

DOI： 10.11471/shikahozon.60.255

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ACADEMIC PRESS INC ELSEVIER SCIENCE  

We previously characterized RNA polymerase II-associated protein 3 (RPAP3) as a cell death enhancer. Here we report the identification and characterization of splicing isoform of RPAP3, isoform 1 and 2. We investigated the interaction between RPAP3 and PIH1 domain containing protein 1 (PIH1D1), and found that RPAP3 isoform 1, but not isoform 2, interacted with PIH1D1. Furthermore, knockdown of RPAP3 isoform 1 by small interfering RNA down-regulated PIH1D1 protein level without affecting PIH1D1 mRNA. RPAP3 isoform 2 potentiated doxorubicin-induced cell death in human breast cancer T-47 cells although isoform 1 showed no effect. These results suggest that R2TP complex is composed of RPAP3 isoform 1 for its stabilization, and that RPAP3 isoform 2 may have a dominant negative effect on the survival potency of R2TP complex.

DOI： 10.1016/j.bbrc.2012.11.017

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記述言語：日本語   出版者・発行元：(NPO)日本歯科保存学会  

J-GLOBAL

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J-GLOBAL

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記述言語：日本語   出版者・発行元：日本歯内療法学会  

J-GLOBAL

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記述言語：日本語   出版者・発行元：日本バイオフィルム学会  

J-GLOBAL

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記述言語：日本語   出版者・発行元：(NPO)日本歯周病学会  

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J-GLOBAL

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J-GLOBAL

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記述言語：日本語   出版者・発行元：(公社)日本薬理学会  

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