Endodontic biofilms: contemporary and future treatment options

유연지,Hiran Perinpanayagam,오소람,A Reum Kim,한승현,금기연 대한치과보존학회 2019 Restorative Dentistry & Endodontics Vol.44 No.1

Apical periodontitis is a biofilm-mediated infection. The biofilm protects bacteria from host defenses and increase their resistance to intracanal disinfecting protocols. Understanding the virulence of these endodontic microbiota within biofilm is essential for the development of novel therapeutic procedures for intracanal disinfection. Both the disruption of biofilms and the killing of their bacteria are necessary to effectively treat apical periodontitis. Accordingly, a review of endodontic biofilm types, antimicrobial resistance mechanisms, and current and future therapeutic procedures for endodontic biofilm is provided.

Effect of acidic solutions on the microhardness of dentin and set OrthoMTA and their cytotoxicity on murine macrophage

오소람,Hiran Perinpanayagam,이윤,Jae-Won Kum,유연지,임상민,장석우,손원준,이우철,백승호,금기연 대한치과보존학회 2016 Restorative Dentistry & Endodontics Vol.41 No.1

mineral trioxide aggregate (MTA) and root dentin, and cytotoxicity on murine macrophage. Materials and Methods: OrthoMTA (BioMTA) was mixed and packed into the human root dentin blocks of 1.5 mm diameter and 5 mm height. Four groups, each of ten roots, were exposed to 10% citric acid (CA), 5% glycolic acid (GA), 17% ethylenediaminetetraacetic acid (EDTA), and saline for five minutes after setting of the OrthoMTA. Vickers surface microhardness of set MTA and dentin was measured before and after exposure to solutions, and compared between groups using one-way ANOVA with Tukey test. The microhardness value of each group was analyzed using student t test. Acid-treated OrthoMTA and dentin was examined by scanning electron microscope (SEM). Cell viability of tested solutions was assessed using WST-8 assay and murine macrophage. Results: Three test solutions reduced microhardness of dentin. 17% EDTA demonstrated severe dentinal erosion, significantly reduced the dentinal microhardness compared to 10% CA (p = 0.034) or 5% GA (p = 0.006). 10% CA or 5% GA significantly reduced the surface microhardness of set MTA compared to 17% EDTA and saline (p < 0.001). Acid-treated OrthoMTA demonstrated microporous structure with destruction of globular crystal. EDTA exhibited significantly more cellular toxicity than the other acidic solutions at diluted concentrations (0.2, 0.5, 1.0%). Conclusions: Tested acidic solutions reduced microhardness of root dentin. Five minute’s application of 10% CA and 5% GA significantly reduced the microhardness of set OrthoMTA with lower cellular cytotoxicity compared to 17% EDTA.

Effect of acidic solutions on the microhardness of dentin and set OrthoMTA and their cytotoxicity on murine macrophage

Oh, Soram,Perinpanayagam, Hiran,Lee, Yoon,Kum, Jae-Won,Yoo, Yeon-Jee,Lim, Sang-Min,Chang, Seok Woo,Shon, Won-Jun,Lee, Woocheol,Baek, Seung-Ho,Kum, Kee-Yeon The Korean Academy of Conservative Dentistry 2016 Restorative Dentistry & Endodontics Vol.41 No.1

Objectives: To evaluate the effects of three acids on the microhardness of set mineral trioxide aggregate (MTA) and root dentin, and cytotoxicity on murine macrophage. Materials and Methods: OrthoMTA (BioMTA) was mixed and packed into the human root dentin blocks of 1.5 mm diameter and 5 mm height. Four groups, each of ten roots, were exposed to 10% citric acid (CA), 5% glycolic acid (GA), 17% ethylenediaminetetraacetic acid (EDTA), and saline for five minutes after setting of the OrthoMTA. Vickers surface microhardness of set MTA and dentin was measured before and after exposure to solutions, and compared between groups using one-way ANOVA with Tukey test. The microhardness value of each group was analyzed using student t test. Acid-treated OrthoMTA and dentin was examined by scanning electron microscope (SEM). Cell viability of tested solutions was assessed using WST-8 assay and murine macrophage. Results: Three test solutions reduced microhardness of dentin. 17% EDTA demonstrated severe dentinal erosion, significantly reduced the dentinal microhardness compared to 10% CA (p = 0.034) or 5% GA (p = 0.006). 10% CA or 5% GA significantly reduced the surface microhardness of set MTA compared to 17% EDTA and saline (p < 0.001). Acid-treated OrthoMTA demonstrated microporous structure with destruction of globular crystal. EDTA exhibited significantly more cellular toxicity than the other acidic solutions at diluted concentrations (0.2, 0.5, 1.0%). Conclusions: Tested acidic solutions reduced microhardness of root dentin. Five minute's application of 10% CA and 5% GA significantly reduced the microhardness of set OrthoMTA with lower cellular cytotoxicity compared to 17% EDTA.

Endodontic biofilms: contemporary and future treatment options

Yoo, Yeon-Jee,Perinpanayagam, Hiran,Oh, Soram,Kim, A-Reum,Han, Seung-Hyun,Kum, Kee-Yeon The Korean Academy of Conservative Dentistry 2019 Restorative Dentistry & Endodontics Vol.44 No.1

Apical periodontitis is a biofilm-mediated infection. The biofilm protects bacteria from host defenses and increase their resistance to intracanal disinfecting protocols. Understanding the virulence of these endodontic microbiota within biofilm is essential for the development of novel therapeutic procedures for intracanal disinfection. Both the disruption of biofilms and the killing of their bacteria are necessary to effectively treat apical periodontitis. Accordingly, a review of endodontic biofilm types, antimicrobial resistance mechanisms, and current and future therapeutic procedures for endodontic biofilm is provided.

Dentinal tubule sealing effects of 532-nm diode-pumped solid-state laser, gallic acid/Fe3+ complex, and three commercial dentin desensitizers

Oh, Soram,Gu, Yu,Perinpanayagam, Hiran,Yoo, Yeon-Jee,Lee, Yoon,Kim, Ryun Kyung,Chang, Seok Woo,Lee, Jongho,Zhu, Qiang,Kum, Kee Yeon Springer-Verlag 2018 LASERS IN MEDICAL SCIENCE Vol.33 No.6

Lactobacillus plantarum lipoteichoic acid disrupts mature Enterococcus faecalis biofilm

A Reum Kim,Minji Kang,Yeon-Jee Yoo,Cheol-Heui Yun,Hiran Perinpanayagam,Kee-Yeon Kum,Seung Hyun Han 한국미생물학회 2020 The journal of microbiology Vol.58 No.4

Apical periodontitis is caused by biofilm-mediated root canal infection. Early phase oral bacterial biofilms are inhibited by Lactobacillus plantarum lipoteichoic acid (Lp.LTA). However, mature biofilms that develop over 3 weeks are more resistant to traditional endodontic medicaments. Therefore, this study examined the effectiveness of Lp.LTA on disrupting mature Enterococcus faecalis biofilms, and on enhancing the effects of endodontic medicaments. LTA was purified from L. plantarum through butanol extraction followed by hydrophobic and ion-exchange chromatography. E. faecalis biofilms were formed over 3 weeks on glass bottom dishes and in dentin blocks obtained from human single-rooted premolars. These mature biofilms were treated with or without Lp.LTA for 1 h, followed by additional treatment with either chlorhexidine digluconate (CHX), calcium hydroxide (CH), or triple antibiotics for 24 h. Biofilms on glass were live/dead stained and quantified by ZEN through confocal laser microscopy. Biofilms in dentin were fixed, sputter coated and analyzed by ImageJ with scanning electron microscopy. Preformed E. faecalis mature biofilms on the culture dishes were dose-dependently disrupted by Lp.LTA. Lp.LTA potentiated the effects of CHX or CH on the disruption of mature biofilm. Interestingly, CHX-induced disruption of preformed E. faecalis mature biofilms was synergistically enhanced only when pretreated with Lp.LTA. Furthermore, in the dentin block model, Lp.LTA alone reduced E. faecalis mature biofilm and pre-treatment with Lp.LTA promoted the anti-biofilm activity of CHX. Lp.LTA could be an anti-biofilm or supplementary agent that can be effective for E. faecalis-biofilminduced diseases.

<i>Lactobacillus plantarum</i> Lipoteichoic Acid Inhibits Oral Multispecies Biofilm

Kim, A Reum,Ahn, Ki Bum,Yun, Cheol-Heui,Park, Ok-Jin,Perinpanayagam, Hiran,Yoo, Yeon-Jee,Kum, Kee-Yeon,Han, Seung Hyun Elsevier 2019 JOURNAL OF ENDODONTICS - Vol.45 No.3

<P><B>Abstract</B></P> <P><B>Introduction</B></P> <P>Apical periodontitis is an inflammatory disease in the periradicular region of teeth that results from infection by multispecies bacterial biofilm residing in the root canal system. In this study, we investigated whether <I>Lactobacillus plantarum</I> lipoteichoic acid (Lp.LTA) could inhibit multispecies oral pathogenic bacterial biofilm formation.</P> <P><B>Methods</B></P> <P>Highly pure and structurally intact Lp.LTA was purified from <I>L. plantarum</I>. <I>Actinomyces naeslundii</I>, <I>Lactobacillus salivarius</I>, <I>Streptococcus mutans</I>, and <I>Enterococcus faecalis</I> were co-cultured to form oral multispecies biofilm in the presence or absence of Lp.LTA on culture plates or human dentin slices. Preformed biofilm was treated with or without Lp.LTA, followed by additional treatment with intracanal medicaments such as calcium hydroxide or chlorhexidine digluconate. Confocal microscopy and crystal violet assay were performed to determine biofilm formation. Biofilm on human dentin slices was visualized with a scanning electron microscope.</P> <P><B>Results</B></P> <P>Biofilm formation of multispecies bacteria on the culture dishes was dose-dependently reduced by Lp.LTA compared with the nontreatment control group. Lp.LTA also inhibited multispecies biofilm formation on the dentin slices in a dose-dependent manner. Interestingly, Lp.LTA was shown to reduce preformed multispecies biofilm compared with the nontreatment group. Moreover, Lp.LTA potentiated the effectiveness of the intracanal medicaments in the removal of preformed multispecies biofilm.</P> <P><B>Conclusions</B></P> <P>These results suggest that Lp.LTA is a potential anti-biofilm agent for treatment or prevention of oral infectious disease, including apical periodontitis, which is mainly caused by multispecies bacterial biofilm.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>Lactobacillus plantarum</I> lipoteichoic acid (Lp.LTA) inhibits oral multispecies biofilm formation. </LI> <LI> Lp.LTA disrupts preformed multispecies biofilm. </LI> <LI> Lp.LTA and intracanal medicaments cooperatively reduce the preformed biofilm. </LI> <LI> Lp.LTA could be used for endodontic treatment against biofilm-associated diseases including apical periodontitis. </LI> </UL> </P>

Antifungal Effects of Synthetic Human Beta-defensin-3-C15 Peptide on <i>Candida albicans</i>–infected Root Dentin

Yoo, Yeon-Jee,Kwon, Ikyung,Oh, So-Ram,Perinpanayagam, Hiran,Lim, Sang-Min,Ahn, Ki-Bum,Lee, Yoon,Han, Seung-Hyun,Chang, Seok-Woo,Baek, Seung-Ho,Zhu, Qiang,Kum, Kee-Yeon Elsevier 2017 JOURNAL OF ENDODONTICS - Vol.43 No.11

<P><B>Abstract</B></P> <P><B>Introduction</B></P> <P>The aim of this study was to assess the antifungal efficacy of a synthetic human beta-defensin-3-C15 peptide (HBD3-C15) in <I>Candida albicans</I>–infected human root dentin.</P> <P><B>Methods</B></P> <P>Standardized root dentin blocks were prepared (6-mm thick, 0.7-mm-wide canal) from single-rooted human permanent premolars and infected with <I>C. albicans</I> for 3 weeks. They were randomly divided into 4 groups (<I>n</I> = 8/group), and their canals were filled with calcium hydroxide (CH), HBD3-C15 peptide, or chlorhexidine digluconate (CHX, 2%) as disinfectants or saline as control. After 1 week of disinfection, dentinal debris were harvested at depths of 200 and 400 μm from the canal lumen, and incubated in Yeast broth for 72 hours at 37°C. Then, colony-forming units (CFU) were measured to assess the antifungal efficacy of each medicament and analyzed statistically.</P> <P><B>Results</B></P> <P>All medicaments showed significantly lower CFU than saline (<I>P</I> < .05), and their antifungal efficacies were similar at both 200- and 400-μm tubular depths (<I>P</I> > .05). HBD3-C15 had similar antifungal efficacy to that of CHX at both depths (<I>P</I> > .05), and both medicaments had significantly lower CFU than CH at both depths (<I>P</I> < .05).</P> <P><B>Conclusions</B></P> <P>In this <I>ex vivo</I> model of <I>C. albicans</I>–infected human root dentin, the antifungal efficacy of synthetic HBD3-C15 was comparable with CHX.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>Candida albicans</I> biofilm is closely related to initiation and persistence of refractory apical periodontitis. </LI> <LI> Antifungal efficacy of various intracanal medicaments were assessed in <I>C. albicans</I>-infected human root dentin. </LI> <LI> In <I>C. albicans</I>-infected human dentin blocks, root canals were covered by mature biofilms with tubular penetration of 400 μm. </LI> <LI> In this standardized <I>ex vivo</I> model, chlorhexidine and synthetic human β-defensin-3-C15 peptide were similar and highly effective at reducing <I>C. albicans</I> CFU, whereas calcium hydroxide had limited efficacy. </LI> </UL> </P>

Bacterial entombment by intratubular mineralization following orthograde mineral trioxide aggregate obturation: a scanning electron microscopy study

Yoo, Jun Sang,Chang, Seok-Woo,Oh, So Ram,Perinpanayagam, Hiran,Lim, Sang-Min,Yoo, Yeon-Jee,Oh, Yeo-Rok,Woo, Sang-Bin,Han, Seung-Hyun,Zhu, Qiang,Kum, Kee-Yeon Nature Publishing Group 2014 International journal of oral science. Vol.6 No.4

<P>The time domain entombment of bacteria by intratubular mineralization following orthograde canal obturation with mineral trioxide aggregate (MTA) was studied by scanning electron microscopy (SEM). Single-rooted human premolars (<I>n</I>=60) were instrumented to an apical size #50/0.06 using ProFile and treated as follows: Group 1 (<I>n</I>=10) was filled with phosphate buffered saline (PBS); Group 2 (<I>n</I>=10) was incubated with <I>Enterococcus faecalis</I> for 3 weeks, and then filled with PBS; Group 3 (<I>n</I>=20) was obturated orthograde with a paste of OrthoMTA (BioMTA, Seoul, Korea) and PBS; and Group 4 (<I>n</I>=20) was incubated with <I>E. faecalis</I> for 3 weeks and then obturated with OrthoMTA–PBS paste. Following their treatments, the coronal openings were sealed with PBS-soaked cotton and intermediate restorative material (IRM), and the roots were then stored in PBS for 1, 2, 4, 8 or 16 weeks. After each incubation period, the roots were split and their dentin/MTA interfaces examined in both longitudinal and horizontal directions by SEM. There appeared to be an increase in intratubular mineralization over time in the OrthoMTA-filled roots (Groups 3 and 4). Furthermore, there was a gradual entombment of bacteria within the dentinal tubules in the <I>E. faecalis</I> inoculated MTA-filled roots (Group 4). Therefore, the orthograde obturation of root canals with OrthoMTA mixed with PBS may create a favorable environment for bacterial entombment by intratubular mineralization.</P>

Antifungal effects of synthetic human β-defensin 3-C15 peptide

임상민,안기범,Christine Kim,Jong-Won Kum,Hiran Perinpanayagam,구유,유연지,장석우,한승현,손원준,이우철,백승호,Qiang Zhu,금기연 대한치과보존학회 2016 Restorative Dentistry & Endodontics Vol.41 No.2

Objectives: The purpose of this ex vivo study was to compare the antifungal activity of a synthetic peptide consisting of 15 amino acids at the C-terminus of human β-defensin 3 (HBD3-C15) with calcium hydroxide (CH) and Nystatin (Nys) against Candida albicans (C. albicans) biofilm. Materials and Methods: C. albicans were grown on cover glass bottom dishes or human dentin disks for 48 hr, and then treated with HBD3-C15 (0, 12.5, 25, 50, 100, 150, 200, and 300 μg/mL), CH (100 μg/mL), and Nys (20 μg/mL) for 7 days at 37℃. On cover glass, live and dead cells in the biomass were measured by the FilmTracer Biofilm viability assay, and observed by confocal laser scanning microscopy (CLSM). On dentin, normal, diminished and ruptured cells were observed by field-emission scanning electron microscopy (FE-SEM). The results were subjected to a twotailed t-test, a one way analysis variance and a post hoc test at a significance level of p = 0.05. Results: C. albicans survival on dentin was inhibited by HBD3-C15 in a dose-dependent manner. There were fewer aggregations of C. albicans in the groups of Nys and HBD3-C15 (≥ 100 μg/mL). CLSM showed C. albicans survival was reduced by HBD3-C15 in a dose dependent manner. Nys and HBD3-C15 (≥ 100 μg/mL) showed significant fungicidal activity compared to CH group (p < 0.05). Conclusions: Synthetic HBD3-C15 peptide (≥ 100 μg/mL) and Nys exhibited significantly higher antifungal activity than CH against C. albicans by inhibiting cell survival and biofilm.