Bacterial reduction in sealed caries lesions is strain- and material-specific

Marggraf, Teresa; Ganas, Petra; Paris, Sebastian; Schwendicke, Falk

doi:10.1038/s41598-018-21842-8

Cited by 18 publications

(7 citation statements)

References 47 publications

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“…Our study confirms findings from in vivo studies, which demonstrated long-term survival of sealed bacteria [10,11]. Strain-specific survival was also demonstrated in vitro recently [12].…”

Section: Discussionsupporting

confidence: 91%

Effect of reduced nutritional supply on the metabolic activity and survival of cariogenic bacteriain vitro

Ganas

Schwendicke

2019

Journal of Oral Microbiology

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Sealed cariogenic bacteria are deprived from dietary carbohydrate, but could be provided with nutrients by pulpal fluids, with adaptive strain-specific activities being possible. We investigated survival and metabolic activity of the cariogenic bacteria Streptococcus sobrinus, Actinomyces naeslundii and Lactobacillus rhamnosus in different carbohydrate-limited media without carbon source (CLM), or containing glucose (CLM-G), albumin (CLM-A), or α1-acid glycoprotein (CLM-AGP) in vitro. Bacterial metabolite concentrations (lactate, pyruvate, oxaloacetate, citrate, acetate, formate, ethanol, acetoin) after 20 and 4 hours incubation, and bacterial numbers (CFU) after 24 hours incubation were analyzed using multivariate-analysis-of-variance (MANOVA). The medium (p = 0.02/MANOVA), strain and incubation-time (both p < 0.001) had significant impact on metabolite concentrations. Bacteria secreted mainly lactate (80.3 µg/10 6 bacteria S. sobrinus) and acetate (54.5 µg/10 6 bacteria A. naeslundii). Nearly all metabolites were produced in higher concentrations in S. sobrinus than in A. naeslundii or L. rhamnosus (p < 0.05/HSD). Metabolite concentration was significantly higher in CLM-G than in other media for most metabolites (p < 0.05). L. rhamnosus showed significantly lower survival than S. sobrinus and A. naeslundii (p < 0.05/HSD) regardless of the media, while S. sobrinus and A. naeslundii showed mediumspecific survival. Survival of carbon starvation was strain-and medium-specific. Sustained organic acid production was found for all strains and media.

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“…Our study confirms findings from in vivo studies, which demonstrated long-term survival of sealed bacteria [10,11]. Strain-specific survival was also demonstrated in vitro recently [12].…”

Section: Discussionsupporting

confidence: 91%

Effect of reduced nutritional supply on the metabolic activity and survival of cariogenic bacteriain vitro

Ganas

Schwendicke

2019

Journal of Oral Microbiology

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“…The significant antibacterial efficacy of SRF-CPC is most likely related to the sustained release of the CPC from the SRF, in addition to the high sensitivity of E. faecalis to CPC [17]. Furthermore, the sealing of the dentinal tubules by the SRF might have caused additional environmental stress to bacteria residing deep inside the tubules [33]. An intimate relation between the SRF and the root canal walls was confirmed using SEM.…”

Section: Discussionmentioning

confidence: 99%

Sustained-Release Fillers for Dentin Disinfection: An Ex Vivo Study

Funk

Sahar-Helft

Kirmayer

et al. 2019

International Journal of Dentistry

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Enterococcus faecalis is the most commonly recovered species from failed root canal treatments. In this study, we tested the capability of a novel intracanal sustained-release filler (SRF) containing cetylpyridinium chloride (CPC) to disinfect dentinal tubules of segmented human tooth specimens. Human dental root specimens were infected with E. faecalis V583 for 3 weeks in a static environment. The tested intracanal medicaments were SRF-CPC and calcium hydroxide (CH). Each medicament was introduced into the canal of the dental specimen and incubated for 7 days. The bacteriological samples were taken by shaving the dentine surrounding the root canal with dental burs ranging in size from ISO 014-020. The obtained dentine powder was collected in test tubes containing phosphate-buffered saline, sonicated, and plated on agar plates. Colony-forming units were counted after 48 h of incubation. Random specimens were also examined under confocal laser scanning microscopy and scanning electron microscopy. A statistical difference was found in the bacterial counts obtained from all layers of infected dentin between the control and the SRF-CPC groups. CH reduced bacterial viability significantly only in the first layer of the infected dentin, up to 150 μm into the dentinal tubules. CLSM images showed that SRF-CPC killed most bacteria throughout the infected dentin up to 700 μm of penetration. SEM images demonstrated the adhesion ability of SRF-CPC to the dentinal wall. In conclusion, SRF-CPC is a potential intracanal medicament for disinfecting dentinal tubules.

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“…From previous investigations it is known, however, that bacteria can be found within enamel lesions at an early stage of caries development, even with lesions revealing macroscopically intact surfaces [63]. Since bacteria control of deeper intralesional aspects has not been investigated up to now, at best, some positive indirect conclusions by analogy from studies referring to sealing of occlusal caries would seem permissible [64], and this would suggest that it is not necessary to remove all carious dentin prior to placing the restoration; over time, sealing of carious dentin obviously will result in lower (time-and material-specific [65]) levels of infection if compared to the traditional concepts aiming at complete dentin caries removal [66]. Certainly, additional research to elucidate the fate of microorganisms hemmed by the external resin infiltration of proximal lesions is required.…”

Section: Discussionmentioning

confidence: 99%

Ex vivo investigation on internal tunnel approach/internal resin infiltration and external nanosilver-modified resin infiltration of proximal caries exceeding into dentin

Kielbassa¹,

Leimer²,

Hartmann³

et al. 2020

PLoS ONE

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This ex vivo proof-of-concept study aimed to investigate the effect of nanosilver particles (AgNP) added to a conventional infiltrant resin (Icon) on external penetration into natural proximal enamel caries exceeding into dentin after internal tunnel preparation and internal infiltration. Carious lesions (ICDAS codes 2/3) of extracted human (pre-)molars revealing proximal caries radiographically exceeding into dentin (E2/D1 lesions) were preselected. Then, 48 of those specimens showing demineralized areas transcending the enamel-dentin border as assessed by means of near-infrared light transillumination (DIAGNOcam) were deproteinized (NaOCl, 5%). Using an internal tunnel approach, occlusal cavities central to the marginal ridge were prepared. Excavation of carious dentin, total etch procedure (H 3 PO 4 , 40%), and internal resin infiltration (FITC-labeled) followed, along with final restorations (flowable composite resin). Outer lesion surfaces were etched (HCl, 15%) prior to external infiltration (RITC-labeled). Group 1 (control; n = 24) used non-modified infiltrant, while an infiltrant/ AgNP mixture (20 nm; 5.5 wt%) was used with experimental Group 2 (n = 24). Non-infiltrated pores of cut lesions were stained (Berberine), and specimens were analyzed using confocal laser scanning microscopy. Compared to the non-filled infiltrant, incorporation of AgNP had no effect on the resin's external penetration. Between the groups, no significant differences regarding internal or external infiltration could be detected, and non-infiltrated lesion areas did not differ significantly (p>0.109; t-test). The internal tunnel preparation in combination with both an internal resin infiltration and an additional external infiltration approach using a nanosilver-modified infiltrant resin leads to increased infiltrated lesion areas, thus occluding and adhesively stabilizing the porous volume of the demineralized enamel. While exerting antimicrobial effects by the nanosilver particles, this approach should have the potential as a viable treatment alternative for proximal lesions extending into dentin, thus avoiding the sacrifice of sound enamel, postponing the frequently inevitable restoration/re-restoration cycle of conventional proximal caries treatment, and improving dental health.

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Bacterial reduction in sealed caries lesions is strain- and material-specific

Cited by 18 publications

References 47 publications

Effect of reduced nutritional supply on the metabolic activity and survival of cariogenic bacteriain vitro

Effect of reduced nutritional supply on the metabolic activity and survival of cariogenic bacteriain vitro

Sustained-Release Fillers for Dentin Disinfection: An Ex Vivo Study

Ex vivo investigation on internal tunnel approach/internal resin infiltration and external nanosilver-modified resin infiltration of proximal caries exceeding into dentin

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