• The Journal of Advanced Prosthodontics
• /
• 제11권2호
• /
• pp.81-87
• /
• 2019

PURPOSE. The purpose of this study was to evaluate the effects of various protocols and systems for finishing and polishing monolithic zirconia on surface topography, phase transformation, and bacterial adhesion. MATERIALS AND METHODS. Three hundred monolithic zirconia specimens were fabricated and then treated with three finishing and polishing systems (Jota [JO], Meisinger [ME], and Edenta [ED]) using four surface treatment protocols: coarse finishing alone (C); coarse finishing and medium polishing (CM); coarse finishing and fine polishing (CF); and coarse finishing, medium polishing, and fine polishing (CMF). Surface roughness, crystal phase transformation, and bacterial adhesion were evaluated using atomic force microscopy, X-ray diffraction, and streptococcal biofilm formation assay, respectively. One-way and two-way analysis of variance with Tukey post hoc tests were used to analyze the results (${\alpha}=.05$). RESULTS. In this study, the surface treatment protocols and systems had significant effects on the resulting roughness. The CMF protocol produced the lowest roughness values, followed by CM and CF. Use of the JO system produced the lowest roughness values and the smallest biofilm mass, while the ME system produced the smallest partial transformation ratio. The ED group exhibited the highest roughness values, biofilm mass, and partial transformation ratio. CONCLUSION. Stepwise surface treatment of monolithic zirconia, combined with careful polishing system selection, is essential to obtaining optimal microstructural and biological surface results.

• 한국치위생학회지
• /
• 제23권4호
• /
• pp.227-234
• /
• 2023

Objectives: Cetylpyridinium chloride CPC-based mouthwashes are well known to have no harmful ingredients in the mouth and can be used for a long time. The purpose of this study was to evaluate the effect of using CPC-based mouthwashes to suppress the biofilm formation and antibiotics for handling orthodontic appliances. Methods: To measure the antibacterial effect, Streptococcus mutans (S. mutans) cultured orthodontic appliances were precipitated in Gargreen and Polident for 5 minutes, incubated at 37℃ for 24 hours(h). In order to measure the biofilm removal effect, the degree of biofilm formation on the orthodontic appliances was stained with a methylene blue and the difference before and after was compared using image J software program (NIH Image J; NIH, Bethesda, MD). Results: The viability of S. mutans according to the concentration showed that Gargreen and Polident inhibited colony formation compared to the control, respectively (p<0.01). The degree of biofilm formation was significantly higher in the control, however both Gargreen and Polident significantly reduced it compared to the before and after condition on removable orthodontic appliances (p<0.01). Conclusions: This study suggests that the use of Gargreen, a cetylpyridinium chloride based oral cleaning cleanser, could be replaced by Polident for antibacterial effect and biofilm formation on removable orthodontic appliances.

• 대한소아치과학회지
• /
• 제50권2호
• /
• pp.131-141
• /
• 2023

치아우식증은 치아, 바이오필름(biofilm), 식이 요인의 상호작용을 기본으로 타액, 불소 등의 구강 환경요인과 생물학적, 행동적, 사회문화적, 유전적 요인이 관여하는 복잡한 다인성질환이다. 최근 치아우식증은 외부 병원체의 감염에 의한 것이 아닌 구강 미생물군의 생태적 변화에 따른 불균형(dysbiosis)의 결과로 이해되면서 전염성질병에서 비전염성 질병(non-communicable diseases, NCD)으로 전환되었다. 치아우식증은 심혈관질환이나 당뇨병과 같이 만성적으로 진행되는 비전염성 질환(NCD) 특성을 가지며, 식이섭취와 생활 습관과 환경적 요소들이 관여한다는 점에서 유사성이 있다. 높은 유병률과 함께 사람들의 건강과 삶의 질에 미치는 영향을 감안할 때 효과적인 구강 건강관리를 목표로 비전염성질환(NCD)로서 치아우식증에 대한 이해가 필요하며, 구강 미생물군의 생태적 균형을 이루기 위한 적절한 예방법과 효율적인 공중보건 정책들이 제공되어야 할 것이다.

• International Journal of Oral Biology
• /
• 제46권3호
• /
• pp.111-118
• /
• 2021

Periodontitis and periimplantitis are caused as a result of dental biofilm formation. This biofilm is composed of multiple species of pathogens. Therefore, controlling biofilm formation is critical for disease prevention. To inhibit biofilm formation, sugars can be used to interrupt lectin-involving interactions between bacteria or between bacteria and a host. In this study, we evaluated the effect of D-Arabinose on biofilm formation of putative periodontal pathogens as well as the quorum sensing activity and whole protein profiles of the pathogens. Crystal violet staining, confocal laser scanning microscopy, and scanning electron microscopy revealed that D-Arabinose inhibited biofilm formation of Porphyromonas gingivalis, Fusobacterium nucleatum, and Tannerella forsythia. D-Arabinose also significantly inhibited the activity of autoinducer 2 of F. nucleatum and the expression of representative bacterial virulence genes. Furthermore, D-Arabinose treatment altered the expression of some bacterial proteins. These results demonstrate that D-Arabinose can be used as an antibiofilm agent for the prevention of periodontal infections.

• The Journal of Advanced Prosthodontics
• /
• 제11권1호
• /
• pp.41-47
• /
• 2019

PURPOSE. Surface finishing of a zirconia restoration is essential after clinical adjustment. Herein, we investigated the effects of a surface finishing protocol for monolithic zirconia on final roughness and bacterial adherence. MATERIALS AND METHODS. Forty-eight disk-shaped monolithic zirconia specimens were fabricated and divided into four groups (n = 12) based on initial surface treatment, finishing, and polishing protocols: diamond bur+polishing bur (DP group), diamond bur+stone grinding bur+polishing bur (DSP group), no diamond bur+polishing bur (NP group), and no diamond bur+stone grinding bur+polishing bur (NSP group). Initial and final surface roughness was measured with a profilometer, and shown using scanning electron microscope. Bacterial adhesion was evaluated by quantifying Streptococcus mutans in the biofilm. Kruskal-Wallis and Mann-Whitney U tests were used to compare results among groups, and two-way analysis of variance was used to evaluate the effects of grinding burs on final roughness (${\alpha}=.05$). RESULTS. The DP group had the highest final Ra value, followed by the DSP, NP, and NSP groups. Use of the stone grinding bur as a coarse-finishing step significantly decreased final Ra values when a diamond bur was used (P<.001). Omission of the stone grinding bur increased biofilm formation on specimen surfaces. Combining a stone grinding bur with silicone polishing burs produced the smallest final biofilm values, regardless of the use of a diamond bur in initial surface treatment. CONCLUSION. Coarse finishing of monolithic zirconia with a stone grinding bur significantly decreased final Ra values and bacterial biofilm formation when surfaces had been roughened by a diamond bur.

• International Journal of Oral Biology
• /
• 제45권4호
• /
• pp.143-151
• /
• 2020

Streptococcus mutans and Streptococcus sobrinus play important roles in dental caries. Coptis chinensis is a natural product with antimicrobial activity against enterobacteria; however, its effects on oral streptococci are still unknown. Therefore, the effects of C. chinensis on the growth and biofilm formation of the representative cariogenic bacteria S. mutans and S. sobrinus were investigated for the possible use of C. chinensis as an anticaries agent. The C. chinensis extract was diluted with sterile distilled water, and 0.1-2.5% of the extract was used in the experiment. The effects of the C. chinensis extract on the growth and glucan formation of S. mutans and S. sobrinus were measured by viable cell counting and spectrophotometry at 650 nm absorbance, respectively. Crystal violet staining was also carried out to confirm the C. chinensis extract's inhibitory effect on biofilm formation. The C. chinensis extract significantly inhibited the growth of S. mutans and S. sobrinus at concentrations of ≥ 0.3% as compared with the control group. The viable cell count of colonies decreased by 1.7-fold and 1.2-fold at 2.5% and 1.25%, respectively, compared with the control group. The biofilm formation of S. mutans and S. sobrinus was inhibited by > 20-fold at C. chinensis extract concentrations of ≥ 1.25% as compared with the control group. In summary, the C. chinensis extract inhibited the growth and biofilm and glucan formation of S. mutans and S. sobrinus. Therefore, C. chinensis might be a potential candidate for controlling dental caries.

• Restorative Dentistry and Endodontics
• /
• 제40권3호
• /
• pp.195-201
• /
• 2015

Objectives: The use of chitosan nanoparticles (CNPs) in endodontics is of interest due to their antibiofilm properties. This study was to investigate the ability of bioactive CNPs to remove the smear layer and inhibit bacterial recolonization on dentin. Materials and Methods: One hundred bovine dentin sections were divided into five groups (n = 20 per group) according to the treatment. The irrigating solutions used were 2.5% sodium hypochlorite (NaOCl) for 20 min, 17% ethylenediaminetetraacetic acid (EDTA) for 3 min and 1.29 mg/mL CNPs for 3 min. The samples were irrigated with either distilled water (control), NaOCl, NaOCl-EDTA, NaOCl-EDTA-CNPs or NaOCl-CNPs. After the treatment, half of the samples (n = 50) were used to assess the chelating effect of the solutions using portable scanning electronic microscopy, while the other half (n = 50) were infected intra-orally to examine the post-treatment bacterial biofilm forming capacity. The biovolume and cellular viability of the biofilms were analysed under confocal laser scanning microscopy. The Kappa test was performed for examiner calibration, and the non-parametric Kruskal-Wallis and Dunn tests (p < 0.05) were used for comparisons among the groups. Results: The smear layer was significantly reduced in all of the groups except the control and NaOCl groups (p < 0.05). The CNPs-treated samples were able to resist biofilm formation significantly better than other treatment groups (p < 0.05). Conclusions: CNPs could be used as a final irrigant during root canal treatment with the dual benefit of removing the smear layer and inhibiting bacterial recolonization on root dentin.

• 치위생과학회지
• /
• 제16권4호
• /
• pp.284-292
• /
• 2016

DUWL에 형성된 바이오필름 제거를 위한 효과적인 소독제의 제시와 새로운 소독제의 개발을 위해 DUWL의 실험실 모델의 확립이 필요하다. 따라서 본 연구에서는 실험실에서 쉽게 구할 수 있는 장비들로 실험실 모델을 제작하여, DUWL 바이오필름을 재현하기 위한 새로운 실험실 모델을 확립하고자 하였다. 사용 중인 DUWL을 통해 수집한 물에서 세균을 모은 후, R2A 액체 배지에서 10일 동안 배양시켰다. 10일 배양시킨 세균액을 $-70^{\circ}C$에 보관하여 사용하였다. $-70^{\circ}C$에 저장한 세균 stock은 R2A 액체배지에 5일 동안 회분 배양시킨 배양액은 모델에서 바이오필름을 형성시키기 위해 사용되었다. 바이오필름 형성 모델은 실험실 내 장비인 1 L 비커에 폴리우레탄 튜빙이 부착된 20 cm 유리막대를 꽂아서 제작하였다. 모델을 멸균시킨 후 R2A 액체배지 300 ml와 5일 동안 회분 배양한 세균액 50 ml을 넣고 stir plate에서 $25^{\circ}C$로 배양시켰다. 배양 2일마다 R2A 액체배지를 교체해주었다. 임상의 상황과 유사한 조건에서 바이오필름을 형성하기 위해 와류상태는 오전 9시에서 오후 6시까지 적용시키고 그 이외의 시간에는(약 15시간) 정체상태로 배양시켰다. 바이오필름 형성은 4일 동안 진행하였으며, 그 후 바이오필름의 두께, 바이오필름을 구성하는 세균의 분포 및 형태학적 특징을 SEM과 CLSM을 사용하여 분석하였다. 4일 바이오필름 형성 후 평균 바이오필름 축적량은 $4.68{\times}10^4CFU/cm^2$였고, 바이오필름의 두께는 $10{\sim}14{\mu}m$였다. 또한 바이오필름을 구성하는 세균들이 부분적으로 응집되어 덩어리를 이루고 있는 양상을 확인할 수 있었다. 본 연구에서 제작한 실험실 모델을 대상으로 차아염소산나트륨, 과산화수소 그리고 클로르헥시딘과 같은 소독제의 효과를 확인하였다. 그 결과 적용된 소독제의 농도가 낮을수록 바이오필름 내 생존한 세균의 수가 많았다. 따라서 우리의 실험실 모델에서 형성시킨 바이오필름은 소독제의 효과를 비교하기 위해 적절한 것으로 판단된다. 우리의 실험실 모델은 향후 DUWL 소독을 위한 새로운 방법의 개발을 위해 유용하게 사용될 것으로 예상된다.

• 한국치위생학회지
• /
• 제24권2호
• /
• pp.131-139
• /
• 2024

Objectives: Oral bacterial samples included subgingival, supragingival, and saliva plaques. As the diversity and number of microorganisms deffer depending on the area of the oral cavity and the method used, an appropriate and reliable collection method is important. The present study investigated oral bacterial sampling methods. Methods: Supragingival dental plaque was collected from the buccal and lingual tooth surfaces of study participants using sterilized cotton swabs. Plaques were collected from the subgingival area using a sterilized curette. Bacterial genomic DNA was extracted using MagNA Pure 96 DNA and Viral NA low-volume kits. Real-time polymerase chain reaction (PCR) was performed using the PowerCheck^TM Periodontitis Pathogens Multiplex Real-time PCR kit. Results: Aggregatibacter actinomycetemcomitans, Prevotella intermedia, and Fusobacterium nucleatum of the orange complex were not observed in the subgingival biofilms of all study participants. For Porphyromonas. gingivalis, a significant correlation was observed between supragingival, subgingival, and total tooth surface biofilms. Compared to the supragingival and subgingival biofilmss, total tooth surface biofilm exhibited the highest bacterial count when the inswabbing method was used. Conclusions: Based on these findings, the supragingival swab method is recommended for oral bacterial research.

• International Journal of Oral Biology
• /
• 제35권4호
• /
• pp.197-202
• /
• 2010

Most oral microorganisms exist as biofilms which initiate formation via the attachment of an early colonizer to host proteins on the tooth surface. Fusobacterium nucleatum act as a bridge between early and late colonizers. Dental biofilms eventually comprise dental pathogens such as Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia. To evaluate the effects of mutual interactions between oral bacteria on the growth of biofilms, periodontopathogens were co-cultured with a $0.4\;{\mu}m$ barrier. Streptococcus gordonii inhibited the growth of F. nucleatum and periodontopathogens. However, F. nucleatum, P. gingivalis and T. denticola activated the growth of other bacteria. A co-culture system of early and late colonizers could be a useful tool to further understand bacterial interactions during the development of dental biofilm.