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Journal of Oral Microbiology Mar 2021: The side effects of present antimicrobials like chlorhexidine (CHX) and the emergence of drug resistance necessitate the development of alternative agents to control...
: The side effects of present antimicrobials like chlorhexidine (CHX) and the emergence of drug resistance necessitate the development of alternative agents to control dental caries. : This study developed a novel small molecule, namely II-6s, and investigated its antimicrobial activities against common oral streptococci associated with dental caries. : The susceptibility of streptococci to II-6s was evaluated by the microdilution method, time-kill assay and scanning electron microscopy. The exopolysaccharides, dead/live bacteria and bacterial composition of the II-6s-treated // 3-species biofilms were analyzed by confocal laser scanning microscopy, fluorescent hybridization and quantitative PCR. The anti-demineralization effect and cytotoxicity of II-6s were evaluated by transverse microradiography and CCK-8 assay, respectively. Repeated exposure of to II-6s was performed to assess if II-6s could induce drug resistance. : II-6s exhibited antimicrobial activity similar to CHX against and and significantly inhibited exopolysaccharides production, live bacteria and the demineralizing capability of the 3-species streptococcal biofilms. Besides, II-6s showed reduced cytotoxicity relative to CHX and did not induce drug resistance in after 15 passages. : - II-6s may serve as a promising part of a successful caries management plan.
PubMed: 33854741
DOI: 10.1080/20002297.2021.1909917 -
Dental Materials Journal Jul 2021We investigated the remineralization effects of Nanoseal (NS) dentin desensitizer on demineralized root dentin. Baseline lesion specimens prepared from bovine root...
We investigated the remineralization effects of Nanoseal (NS) dentin desensitizer on demineralized root dentin. Baseline lesion specimens prepared from bovine root dentin were immersed in artificial saliva (AS) or deionized water (DW) after treatment with NS or fluoride-free Nanoseal (NS(-)). Treatment and control groups comprised: 1, AS; 2, NS/AS; 3, NS(-)/AS; 4,NS/DW; 5, NS(-)/DW; and 6, baseline demineralization. Integrated mineral loss (IML) and lesion depth (LD) were determined by transverse microradiography. Fluoride concentrations in the immersion solutions were measured. AS, NS/AS and NS(-)/AS showed higher mineral volume % at the surface and lesion body than did other groups. NS/AS showed significantly lower IML than did AS. There was no significant difference in IML between NS/AS and NS(-)/AS. The highest concentration of fluoride was in the NS/AS immersion solution. The findings suggest Nanoseal facilitated remineralization of demineralized root dentin, and fluoride and other ions included may have contributed to this effect.
Topics: Animals; Cariostatic Agents; Cattle; Dentin; Fluorides; Microradiography; Nanoparticles; Tooth Demineralization; Tooth Remineralization; Tooth Root
PubMed: 33827998
DOI: 10.4012/dmj.2020-288 -
Heliyon Mar 2021To investigate the antimicrobial potential of organo-selenium compound when applied as enamel surface sealant or primer (DenteShield™ [DS]) around orthodontic brackets...
OBJECTIVES
To investigate the antimicrobial potential of organo-selenium compound when applied as enamel surface sealant or primer (DenteShield™ [DS]) around orthodontic brackets to prevent enamel demineralization.
METHODS
Human teeth were randomly assigned to seven treatment groups (15/group): control (No primer or sealant), Leopard light primer (LLP), DS Primer (DS-P), DS Enamel Surface Sealant (DS-S), Pro Seal, Opal Seal and combined DS-P/DS-S (DS-PS). Following etching, the tooth surface was coated with their respective material (except control group) and a bracket was bonded on each treated surface. All samples were subject to cariogenic challenge in a continuous flow microbial caries model at 37 °C in an incubator for 28 days. Demineralization was evaluated with Transerse microradiography to determine mineral loss (Δz) and lesion depth (LD). Data was statistically analyzed using Bonferroni protected Mann-Whitney tests (α = 0.05).
RESULTS
Demineralization was obsessrved only in Control and LLP groups. Control group had significantly (p < 0.001) greater mean LD (109.47 ± 34.22 μm) and mean Δz (2251.07 ± 514.26 vol%μm) when compared with the LLP with mean LD (44.98 ± 11.69 μm) and Δz (700.67 ± 310.66 vol%μm). All other groups did not develop any lesions.
CONCLUSIONS
Selenium-based primer and sealant used alone or in combination were effective in protecting enamel from demineralization around brackets. The combination of primer and enamel surface sealant has no added benefit.
SIGNIFICANCE
DS-S and DS-P containing antimicrobial organo-selenium compound can prevent whitespot lesions development when applied on tooth surface during orthodontic treatment. Light primer applied alone on tooth surface may not provide adequate protection for the enamel around orthodontic appliances.
PubMed: 33748508
DOI: 10.1016/j.heliyon.2021.e06490 -
Scientific Reports Mar 2021This in vitro study evaluated the protective effect of titanium tetrafluoride (TiF) varnish and silver diamine fluoride (SDF) solution on the radiation-induced dentin...
This in vitro study evaluated the protective effect of titanium tetrafluoride (TiF) varnish and silver diamine fluoride (SDF) solution on the radiation-induced dentin caries. Bovine root dentin samples were irradiated (70 Gy) and treated as follows: (6 h): 4% TiF varnish; 5.42% NaF varnish; 30% SDF solution; placebo varnish; or untreated (negative control). Microcosm biofilm was produced from human dental biofilm (from patients with head-neck cancer) mixed with McBain saliva for the first 8 h. After 16 h and from day 2 to day 5, McBain saliva (0.2% sucrose) was replaced daily (37 °C, 5% CO) (biological triplicate). Demineralization was quantified by transverse microradiography (TMR), while biofilm was analyzed by using viability, colony-forming units (CFU) counting and lactic acid production assays. The data were statistically analyzed by ANOVA (p < 0.05). TiF and SDF were able to reduce mineral loss compared to placebo and the negative control. TiF and SDF significantly reduced the biofilm viability compared to negative control. TiF significantly reduced the CFU count of total microorganism, while only SDF affected total streptococci and mutans streptococci counts. The varnishes induced a reduction in lactic acid production compared to the negative control. TiF and SDF may be good alternatives to control the development of radiation-induced dentin caries.
Topics: Animals; Cattle; Dental Caries; Dentin; Fluorides, Topical; Quaternary Ammonium Compounds; Radiation Injuries, Experimental; Radiation-Protective Agents; Silver Compounds; Titanium; X-Rays
PubMed: 33727650
DOI: 10.1038/s41598-021-85748-8 -
Materials (Basel, Switzerland) Feb 2021selective caries excavation (SE) is recommended for deep carious lesions. Bulk fill composites (BF) may be considered to restore SE-cavities. We compared the...
OBJECTIVES
selective caries excavation (SE) is recommended for deep carious lesions. Bulk fill composites (BF) may be considered to restore SE-cavities. We compared the susceptibility for secondary caries adjacent to BF versus incrementally filled composites (IF) in SE and non-selectively excavated teeth (NS) in vitro.
METHODS
in 72 extracted human premolars, artificial caries lesions were induced on pulpo-axial walls of standardized cavities. The lesions were left (SE) or removed (NS), and teeth were restored using two BF, GrandioSO x-tra/Voco (BF-Gra) and SDR/Dentsply (BF-SDR), and an IF, GrandioSO/Voco (IF-Gra) (n = 12/group for SE and NS). After thermo-mechanical cycling (5-55 °C, 8 days), teeth were submitted to a continuous-culture biofilm model with cyclic loading for 10 days. Mineral loss (ΔZ) of enamel surface lesions (ESL), dentin surface lesions (DSL), and dentin wall lesions (DWL) was analyzed using transversal microradiography.
RESULTS
ΔZ was the highest in DSL, followed by ESL, and it was significantly lower in DWL. There were no significant differences in ΔZ between groups in DSL, ESL, and DWL ( > 0.05). Regardless of lesion location, ΔZ did not differ between SE and NS ( > 0.05).
CONCLUSIONS
BF and IF both showed low risks for DWL (i.e., true secondary caries) after SE in vitro, and surface lesion risk was also not significantly different between materials. SE did not increase secondary caries risk as compared with NS.
CLINICAL SIGNIFICANCE
the risk of secondary caries was low after selective excavation in this study, regardless of whether bulk or incrementally filled composites were used.
PubMed: 33669469
DOI: 10.3390/ma14040939 -
Swiss Dental Journal May 2021This study evaluated the antimicrobial (anti-biofilm) and anti-caries (enamel demineralization prevention) effects of a new cystatin derived from sugarcane (CaneCPI-5)....
This study evaluated the antimicrobial (anti-biofilm) and anti-caries (enamel demineralization prevention) effects of a new cystatin derived from sugarcane (CaneCPI-5). Microcosm biofilm was produced on bovine enamel specimens (4 x 4 mm; n=48) from a mixture of human saliva and McBain saliva at the first 8 h. From this moment until the end of the experiment, the enamel specimens were exposed to lsaMcBain saliva containing 0.2% sucrose and, once a day, they were treated with the test solutions for 1 min. This treatment was performed for 5 days. The solutions evaluated were: PBS (negative control), 0.12% chlorhexidine (positive control), 0.1 mg/ml CaneCPI-5 and 1.0 mg/ml CaneCPI-5. The biofilm viability was determined by fluorescence using confocal microscopy and the enamel demineralization was quantified using transverse microradiography (TMR). The data were analyzed by ANOVA/Tukey or Kruskal-Wallis/Dunn tests for biofilm and enamel, respectively (p<0.05). With respect to the antimicrobial effect, all treatment solutions significantly reduced the biofilm viability compared with PBS. The best antimicrobial effect was found for 1.0 mg/ml CaneCPI-5 (82.37±10.01% dead bacteria) that significantly differed from 0.12% chlorhexidine (73.13±15.07% dead bacteria). For the anti-caries effect, only 0.12% chlorhexidine (ΔZ: 2610, 1683-4343) performed significantly better than PBS (ΔZ: 8030, 7213-9115), but 0.12% chlorhexidine did not significantly differ from 0.1 mg/ml Cane-CPI-5. Under this experimental model, CaneCPI-5 significantly reduced the biofilm viability, but this effect was not reflected on its anti-caries potential.
Topics: Animals; Anti-Infective Agents; Biofilms; Cariostatic Agents; Cattle; Cystatins; Dental Caries; Humans; Saccharum; Saliva; Streptococcus mutans; Tooth Demineralization
PubMed: 33515229
DOI: 10.61872/sdj-2021-05-730 -
Lasers in Surgery and Medicine Sep 2021Previous studies have shown that large changes in the diffuse reflectivity of caries lesions during drying with air can be used to assess lesion activity. The largest...
BACKGROUND AND OBJECTIVES
Previous studies have shown that large changes in the diffuse reflectivity of caries lesions during drying with air can be used to assess lesion activity. The largest changes occur at short wavelength infrared (SWIR) wavelengths coincident with high water absorption. The strongest water absorption in the SWIR occurs at 1950 nm. In this study changes in the reflectivity of simulated lesions with varying degrees of remineralization was measured at 1500-2340 nm and at 1950 nm as the samples were dried with air.
STUDY DESIGN/MATERIALS AND METHODS
Twenty bovine enamel surfaces each with five treatment windows were exposed to two demineralization/remineralization regimens to produce simulated lesions of varying depth, severity, and mineral gradients. An extended range tungsten-halogen lamp with a long pass filter (1500-2340 nm) and a broadband amplified spontaneous emission source centered near the peak of the water-absorption band at 1950-nm were used as light sources and an extended range InGaAs camera (1000-2340 nm) was used to acquire reflected light images as the samples were dried with air. Lesions were also assessed using digital microscopy, polarized light microscopy, optical coherence tomography, and transverse microradiography.
RESULTS
Both wavelength ranges showed extremely high lesion contrast (>0.9) for all six lesion treatment windows in both models. The change in contrast (ΔI) was significantly higher for the 1950 nm broadband source for all the intact lesion windows compared with the 1500-2340 nm wavelength range.
CONCLUSION
SWIR light at 1950 nm yields extremely high contrast of demineralization and appears to be the optimum wavelength for the assessment of lesion activity on tooth coronal surfaces. Lasers Surg. Med. 00:00-00, 2020. © 2020 Wiley Periodicals LLC.
Topics: Animals; Cattle; Dental Enamel; Microscopy, Polarization; Spectroscopy, Near-Infrared; Tomography, Optical Coherence; Tooth Demineralization
PubMed: 33442896
DOI: 10.1002/lsm.23371 -
Molecules (Basel, Switzerland) Jan 2021Developing artificial caries lesions with varying characteristics is needed to adequately study caries process in vitro. The objective of this study was to investigate...
Developing artificial caries lesions with varying characteristics is needed to adequately study caries process in vitro. The objective of this study was to investigate artificial caries lesion characteristics after secondary demineralization protocol containing theobromine and fluoride. Sixty bovine enamel slabs (4 × 3 mm) were demineralized using a Carbopol-containing protocol for 6 days. A baseline area (2 × 3 mm) was protected with acid-resistant nail varnish, after which specimens were exposed for 24 h to a secondary demineralization protocol containing acetic acid plus one of four fluoride/theobromine combinations ( = 15): theobromine (50 or 200 ppm) and fluoride (0 or 1 ppm). Specimens were sectioned and analyzed using transverse microradiography for changes in mineral content, lesion depth, and surface layer mineralization. Data was analyzed using paired t-test and analysis of variance followed by Bonferroni test at 0.05 significance level. After secondary demineralization, fluoride-containing groups had significantly deeper lesions ( = 0.002 and 0.014) compared to the group with 0 ppm fluoride and 50 ppm theobromine. Mineral content and lesion depth were significantly different compared to baseline for all groups. Theobromine did not show an added effect on mineral uptake. Theobromine-containing groups exhibited particularly deep lesions with a more uniform mineral profile in the presence of fluoride.
Topics: Animals; Bronchodilator Agents; Cattle; Dental Caries; Dental Enamel; Fluorides; Theobromine; Tooth; Tooth Demineralization
PubMed: 33435546
DOI: 10.3390/molecules26020300 -
Journal of Bone and Mineral Research :... Jun 2021Bisphosphonates (BPs) are the most widely used drugs for the treatment of osteoporosis but prolonged use of BPs might increase the risk of atypical femur fracture (AFF)....
Bisphosphonates (BPs) are the most widely used drugs for the treatment of osteoporosis but prolonged use of BPs might increase the risk of atypical femur fracture (AFF). There are only a few studies that address the bone material quality in patients on long-term BP treatment with or without AFFs. We analyzed 52 trans-iliac bone biopsies from patients on long-term BP therapy with (n = 26) and without (n = 26) AFF. At the microscopic level, the degree of mineralization of bone (DMB) was assessed on whole bone by X-ray digitized microradiography while microhardness by Vickers microindentation, and bone matrix characteristics by Fourier transform infrared microspectroscopy (FTIRM) (mineral/organic ratio, mineral maturity and crystallinity, and collagen maturity) were measured at random focal areas. The AFF patients were treated longer than non-AFF patients (9.7 ± 3.3 years versus 7.9 ± 2.7 years). As expected, bone remodeling was low in both groups, without difference between them. The AFF group had significantly higher DMB in cortical bone (+2.9%, p = .001), which remained so after adjusting for treatment duration (p = .007), and showed a trend in cancellous bone (+1.6%, p = .05). Consistent with higher DMB, heterogeneity index (HI) was lower in the AFF than in the non-AFF group, illustrating lower heterogeneity of mineralization in the AFF group. A significant positive correlation between the duration of treatment and DMB in cortical bone was found in AFF, and not in the non-AFF group. Microhardness and bone matrix characteristics were similar between groups. We conclude that the AFF group had a duration-dependent increase in DMB leading to a significantly higher DMB than the non-AFF. Because BPs have high affinity to bone mineral and lining the walls of the osteocyte lacunae, the accumulation of matrix-bound BPs in AFF could lead to inhibition of the osteocyte cytoskeleton blunting their response to mechanical strains, a hypothesis to be further investigated. © 2021 American Society for Bone and Mineral Research (ASBMR).
Topics: Bone Density Conservation Agents; Bone Matrix; Bone Remodeling; Diphosphonates; Femoral Fractures; Femur; Humans
PubMed: 33434290
DOI: 10.1002/jbmr.4244 -
Clinical Oral Investigations Jun 2021The aim of this study was to evaluate the influence of different bleaching gels on the masking and caries-arresting effects of infiltrated and non-infiltrated stained...
OBJECTIVES
The aim of this study was to evaluate the influence of different bleaching gels on the masking and caries-arresting effects of infiltrated and non-infiltrated stained artificial enamel caries lesions.
MATERIALS AND METHODS
Bovine enamel specimens (n = 240) with each two sound areas (SI and SC) and each two lesions (DI and DC) were infiltrated (DI and SI), stained (1:1 red wine-coffee mixture,70 days), and randomly distributed in six groups to be bleached with the following materials: 6%HP (HP-6), 16%CP (CP-16), 35%HP (HP-35), 40%HP (HP-40), and no bleaching (NBl,NBl-NBr). Subsequently, specimens were pH-cycled (28 days, 6 × 60 min demineralization/day) and all groups except NBl-NBr were brushed with toothpaste slurry (1.100 ppm, 2×/day, 10 s). Differences in colorimetric values (ΔL, ΔE) and integrated mineral loss (ΔΔZ) between baseline, infiltration, staining, bleaching, and pH cycling were calculated using photographic and transversal microradiographic images.
RESULTS
At baseline, significant visible color differences between DI and SC were observed (ΔE = 12.2; p < 0.001; ANCOVA). After infiltration, these differences decreased significantly (ΔE = 3.8; p < 0.001). Staining decreased and bleaching increased ΔL values significantly (p ≤ 0.001). No significant difference in ΔΔE was observed between before staining and after bleaching (ΔE = 4.3; p = 0.308) and between the bleaching agents (p = 1.000; ANCOVA). pH-cycling did not affect colorimetric values (ΔE = 4.0; p = 1.000). For DI, no significant change in ΔZ during in vitro period was observed (p ≥ 0.063; paired t test).
CONCLUSIONS
Under the conditions chosen, the tested materials could satisfactorily bleach infiltrated and non-infiltrated stained enamel. Furthermore, bleaching did not affect the caries-arresting effect of the infiltration.
CLINICAL RELEVANCE
The present study indicates that bleaching is a viable way to satisfactorily recover the appearance of discolored sound enamel and infiltrated lesions.
Topics: Animals; Cattle; Dental Caries; Dental Caries Susceptibility; Dental Enamel; Gels; Hydrogen Peroxide; Microradiography; Tooth Bleaching; Tooth Bleaching Agents
PubMed: 33319337
DOI: 10.1007/s00784-020-03732-4