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Dental Materials Journal Mar 2019This study aimed to non-destructively analyze the progression of subsurface enamel caries using swept-source optical coherence tomography (SS-OCT), a recently developed...
This study aimed to non-destructively analyze the progression of subsurface enamel caries using swept-source optical coherence tomography (SS-OCT), a recently developed imaging analysis modality. Artificial enamel caries at various stages of demineralization were created in bovine tooth enamel using a modified lactic acid gel system. Untreated enamel served as a control. OCT images from cross-sections of enamel were collected. Mineral density, distribution, and histological changes were analyzed using an electron probe microanalyzer, scanning electron microscopy, and contact microradiography. The Raman spectrum and X-ray structural analysis of the enamel surfaces were determined. SS-OCT detected significant differences in mineral loss among the samples. A high-brightness image was confirmed, along with changes in the respective brightness graphs proportionate to the degree of demineralization. SS-OCT can potentially be used to evaluate the progression of incipient enamel carious lesions.
Topics: Animals; Cattle; Dental Caries; Dental Enamel; Microradiography; Tomography, Optical Coherence; Tooth Demineralization
PubMed: 30713283
DOI: 10.4012/dmj.2017-404 -
Dental Materials : Official Publication... Apr 2016Current clinical methods for diagnosing secondary caries are unreliable for identifying the early stages of decay around restorative materials. The objective of this...
BACKGROUND AND OBJECTIVES
Current clinical methods for diagnosing secondary caries are unreliable for identifying the early stages of decay around restorative materials. The objective of this study was to access the integrity of restoration margins in natural teeth using near-infrared (NIR) reflectance and transillumination images at wavelengths between 1300 and 1700-nm and to determine the optimal NIR wavelengths for discriminating composite materials from dental hard tissues.
MATERIALS AND METHODS
Twelve composite margins (n=12) consisting of class I, II and V restorations were chosen from ten extracted teeth. The samples were imaged in vitro using NIR transillumination and reflectance, polarization sensitive optical coherence tomography (PS-OCT) and a high-magnification digital microscope. Samples were serially sectioned into 200-μm slices for histological analysis using polarized light microscopy (PLM) and transverse microradiography (TMR). Two independent examiners evaluated the presence of demineralization at the sample margin using visible detection with 10× magnification and NIR images presented digitally. Composite restorations were placed in sixteen sound teeth (n=16) and imaged at multiple NIR wavelengths ranging from λ=1300 to 1700-nm using NIR transillumination. The image contrast was calculated between the composite and sound tooth structure.
RESULTS
Intensity changes in NIR images at wavelengths ranging from 1300 to 1700-nm correlate with increased mineral loss measured using TMR. NIR reflectance and transillumination at wavelengths coincident with increased water absorption yielded significantly higher (P<0.001) contrast between sound enamel and adjacent demineralized enamel. In addition, NIR reflectance exhibited significantly higher (P<0.01) contrast between sound enamel and adjacent composite restorations than visible reflectance.
SIGNIFICANCE
This study shows that NIR imaging is well suited for the rapid screening of secondary caries lesions.
Topics: Composite Resins; Dental Caries; Dental Restoration, Permanent; Humans; In Vitro Techniques; Lasers, Gas; Microradiography; Microscopy, Polarization; Spectroscopy, Near-Infrared; Tomography, Optical Coherence; Tooth Demineralization; Transillumination
PubMed: 26876234
DOI: 10.1016/j.dental.2016.01.008 -
Bone Oct 2019Bone loss in anorexia nervosa and following bariatric surgery is associated with an elevated circulating concentration of the gastrointestinal, anorexigenic hormone,...
OBJECTIVE
Bone loss in anorexia nervosa and following bariatric surgery is associated with an elevated circulating concentration of the gastrointestinal, anorexigenic hormone, peptide YY (PYY). Selective deletion of the PYY receptor Y1R in osteoblasts or Y2R in the hypothalamus results in high bone mass, but deletion of PYY in mice has resulted in conflicting skeletal phenotypes leading to uncertainty regarding its role in the regulation of bone mass. As PYY analogs are under development for treatment of obesity, we aimed to clarify the relationship between PYY and bone mass.
METHODS
The skeletal phenotype of Pyy knockout (KO) mice was investigated during growth (postnatal day P14) and adulthood (P70 and P186) using X-ray microradiography, micro-CT, back-scattered electron scanning electron microscopy (BSE-SEM), histomorphometry and biomechanical testing.
RESULTS
Bones from juvenile and Pyy KO mice were longer (P < 0.001), with decreased bone mineral content (P < 0.001). Whereas, bones from adult Pyy KO mice had increased bone mineral content (P < 0.05) with increased mineralisation of both cortical (P < 0.001) and trabecular (P < 0.001) compartments. Long bones from adult Pyy KO mice were stronger (maximum load P < 0.001), with increased stiffness (P < 0.01) and toughness (P < 0.05) compared to wild-type (WT) control mice despite increased cortical vascularity and porosity (P < 0.001). The increased bone mass and strength in Pyy KO mice resulted from increases in trabecular (P < 0.01) and cortical bone formation (P < 0.05).
CONCLUSIONS
These findings demonstrate that PYY acts as a negative regulator of osteoblastic bone formation, implicating increased PYY levels in the pathogenesis of bone loss during anorexia or following bariatric surgery.
Topics: Animals; Bone Density; Bone Development; Bone Resorption; Bone and Bones; Calcification, Physiologic; Cortical Bone; Female; Femur; Male; Mice, Inbred C57BL; Mice, Knockout; Organ Size; Osteoclasts; Peptide YY; Porosity
PubMed: 31306808
DOI: 10.1016/j.bone.2019.07.011 -
Osteoarthritis and Cartilage Oct 2014To investigate and validate digital X-ray microradiography as a novel, high-throughput and cost-effective screening approach to identify abnormal joint phenotypes in...
OBJECTIVE
To investigate and validate digital X-ray microradiography as a novel, high-throughput and cost-effective screening approach to identify abnormal joint phenotypes in mice.
METHOD
Digital X-ray microradiography was used to quantify the subchondral bone mineral content (BMC) in the medial tibial plateau. Accuracy and reproducibility of the method were determined in 22 samples from C57BL/6(B6Brd;B6Dnk;B6N-Tyr(c-Brd)) wild-type mice. The method was then validated in wild-type mice that had undergone surgical destabilisation of medial meniscus (DMM) and in a genetically modified mouse strain with an established increase in trabecular bone mass.
RESULTS
The measurement of subchondral BMC by digital X-ray microradiography had a coefficient of variation of 3.6%. Digital X-ray microradiography was able to demonstrate significantly increased subchondral BMC in the medial tibial plateau of male mice 4 and 8 weeks after DMM surgery and in female mice 8 weeks after surgery. Furthermore, digital X-ray microradiography also detected the increase in subchondral BMC in a genetically modified mouse strain with high trabecular bone mass.
CONCLUSION
Quantitation of subchondral BMC by digital X-ray microradiography is a rapid, sensitive and cost-effective method to identify abnormal joint phenotypes in mice of both genders at several ages.
Topics: Animals; Bone Density; Disease Models, Animal; Female; Knee Joint; Male; Menisci, Tibial; Mice; Mice, Inbred C57BL; Microradiography; Osteoarthritis, Knee; Phenotype; Reproducibility of Results; Tibia
PubMed: 24792211
DOI: 10.1016/j.joca.2014.04.015 -
The Journal of Clinical Pediatric... 2019Calcium phosphate and fluoride (F) delivery systems claim to facilitate enamel remineralization.
BACKGROUND
Calcium phosphate and fluoride (F) delivery systems claim to facilitate enamel remineralization.
AIM
To evaluate and compare (i) the remineralizing potential of Clinpro Tooth Crème(CTC) and Tooth Mousse Plus(TMP) on artificial carious lesions, and (ii) the benefit of 1000ppm F dentifrice prior to the application of CTC and TMP.
STUDY DESIGN
Carious lesions, 200-300μm deep were produced by placing molars in demineralizing solution for 96h, sections 100-150μm thick were then randomly assigned to six groups(n=150). Specimens were treated thrice daily with a non-fluoridated(Group A), or fluoridated dentifrice[1000ppm, (Group B)], or CTC(Group C), TMP(Group D), fluoridated dentifrice followed by CTC(Group E), or a fluoridated dentifrice followed by TMP(Group F), and then subjected to a 10-day pH cycling model. Lesion evaluation involved polarizing light microscopy and microradiography.
RESULTS
Posttreatment maximum mineral content at the surface zone(V) was significantly increased in Groups B, C, and D compared to the other groups. The lesion depth(LD) decreased in Group D>Group C>Group E, and the net mineral content gain(ΔZ) in Group C>Group D, which did not reach statistical significance.
CONCLUSIONS
CTC and TMP exhibited similar efficacy in remineralizing artificial carious lesions. Nevertheless, the net mineral gain or lesion consolidation following CTC use was higher than TMP.
Topics: Cariostatic Agents; Caseins; Dental Caries; Fluorides; Humans; Hydrogen-Ion Concentration; Random Allocation; Tooth Remineralization
PubMed: 30730799
DOI: 10.17796/1053-4625-43.2.6 -
Clinical Oral Implants Research Oct 2014The aim of this study was to compare microradiography (MR) and microcomputed tomography (μCT) analysis of bone samples following maxillary sinus augmentation at... (Comparative Study)
Comparative Study
OBJECTIVES
The aim of this study was to compare microradiography (MR) and microcomputed tomography (μCT) analysis of bone samples following maxillary sinus augmentation at different time periods and determine the relationships between measured area and volume fractions.
MATERIALS AND METHODS
Lateral window sinus grafts were performed on 10 patients using a mineralized human bone allograft (MHBA). At implant placement, 5-13 months after surgery, 10 bone core biopsies were harvested. Prior to histologic sectioning, bone samples were evaluated with μCT. The morphometric parameters computed by MR and μCT were compared using Pearson's correlation and Bland and Altman analysis and included hard tissue fraction (HV/TV:%), soft tissue fraction (SV/TV:%), vital bone fraction (BV/TV:%) and residual graft fraction (GV/TV:%).
RESULTS
Strong positive correlation between MR and μCT was found for HV/TV and SV/TV and BV/TV [r = 0.84, 0.84 and 0.69, respectively] but weak for GV/TV [r = 0.10].
CONCLUSION
μCT technology shows promising potential as an indicator of bone morphology changes; however, caution should be used in interpreting morphometric parameters, as the different methods reveal important biases.
Topics: Adult; Aged; Female; Humans; Imaging, Three-Dimensional; Italy; Male; Maxillary Sinus; Microradiography; Middle Aged; Radiography, Panoramic; Sinus Floor Augmentation; Tomography, X-Ray Computed; Treatment Outcome; X-Ray Microtomography
PubMed: 23796003
DOI: 10.1111/clr.12225 -
Clinical, Cosmetic and Investigational... 2021The effectiveness of a hydroxyapatite (HAP) toothpaste and a fluoride toothpaste in preventing root tissue demineralization (root caries) was compared using an...
PURPOSE
The effectiveness of a hydroxyapatite (HAP) toothpaste and a fluoride toothpaste in preventing root tissue demineralization (root caries) was compared using an established pH-cycling caries model.
MATERIALS AND METHODS
Sixty dentin blocks were produced from the root tissue of extracted human teeth and were assigned to 3 test groups (n=20/group): 10% hydroxyapatite toothpaste (HAP), 1450 ppm fluoride toothpaste (fluoride), and artificial saliva (artsaliva). Early root caries lesions were developed in each sample by 7-day demineralization using a pH-cycling caries model. The daily cyclic treatment regimen consists of two 2-minute toothpaste-slurry treatment periods, one 6-hour acid challenge using acidified gel (pH 4.5), and then storage in remineralizing solution (artsaliva) for the rest of the time. Demineralization was assessed as the amount of mineral loss (∆z) using transverse microradiography (TMR). Pairwise comparisons (between treatments) were performed using analysis of variance (ANOVA), and then Tukey's HSD for multiple comparisons. All p-values are considered significant if p<0.05.
RESULTS
Both ANOVA and Tukey's HSD indicated no significant (ANOVA; n=20) difference in mean ∆z among the groups, with least ∆z (±Sd) in the HAP (1117±366) compared to fluoride (1392±334) and artsaliva (1406±223). Relative to control, HAP and fluoride inhibited root demineralization by 21% and 6%, respectively.
CONCLUSION
Within the limit of the present study, the tested toothpaste containing 10% HAP is an effective root caries control toothpaste. Toothpaste containing 10% HAP was slightly more effective in preventing tooth demineralization than 1450 ppm fluoride provided as sodium fluoride. Thus, this study shows that HAP toothpastes can serve as an effective alternative to fluoride toothpastes for root caries management.
PubMed: 34321930
DOI: 10.2147/CCIDE.S319631 -
Archives of Oral Biology Oct 2017Capillarity theory predicts that the pore volume infiltrated by a liquid in a body with tubular capillaries is directly proportional to the capillary radius. The...
AIM
Capillarity theory predicts that the pore volume infiltrated by a liquid in a body with tubular capillaries is directly proportional to the capillary radius. The expected volume available for infiltration is the loosely bound water volume, which can be related to the capillary radii. We tested the hypothesis that the proportion of the pore volume infiltrated by resin infiltrant (V) is correlated and agrees with the proportion of the pore volume with loosely bound water ( [Formula: see text] ).
DESIGN
Seven human fluorotic third molars (4 unerupted and 3 erupted; TF scores 4 to 7; fluoride content of inner coronal dentin ranged from 143 to 934μg Fluoride/g) were prepared and resin infiltration was performed during 10min in fluorotic enamel ground sections. Penetration depths were measured (polarizing microscopy and CLSM) and mineral volume and non-mineral volumes were measured at histological points (n=92) along transversal lines traced from the enamel surface to the enamel-dentin junction.
RESULTS
No well-mineralized surface layer was found. Infiltration depths ranged from 250μm to 900μm. V ranged from 1.8 to 17.7% (mean of 10.13%±4.1%), was lower than [Formula: see text] (p<0.00001 Hedge's g=1.51, 95% CI: 1.18/1.83), and correlated positively with [Formula: see text] (R=0.684; 95% CI: 0.557/0.780) and negatively with the air volume remained after infiltration (R=-0.79; 95% CI: -0.698/-0.780). [Formula: see text] exceeded V in 5% (1/4 of [Formula: see text] ) on average.
CONCLUSION
[Formula: see text] and V correlated well, but lacked good agreement. Organic matter, firmly bound water and air remained in enamel pores after resin infiltration.
Topics: Composite Resins; Dental Enamel; Fluorosis, Dental; Humans; In Vitro Techniques; Microradiography; Microscopy, Confocal; Microscopy, Polarization; Molar, Third; Permeability; Porosity; Surface Properties
PubMed: 28641179
DOI: 10.1016/j.archoralbio.2017.06.017 -
Journal of Applied Oral Science :... 2022The initial characteristics of white spot lesion (WSLs), such as the degree of integrated mineral loss (ΔZ), depth and pattern of mineral distribution, have an impact...
UNLABELLED
The initial characteristics of white spot lesion (WSLs), such as the degree of integrated mineral loss (ΔZ), depth and pattern of mineral distribution, have an impact on further demineralization and remineralization. However, these lesion parameters have not been evaluated in WSLs produced from microcosm biofilms.
OBJECTIVE
This study characterized artificial white spot lesions produced on human enamel under microcosm biofilm for different experimental periods.
METHODOLOGY
In total, 100 human enamel specimens (4x4mm) were assigned to 5 distinct groups (n=20/group) differing according to the period of biofilm formation (2, 4, 6, 8 or 10 days). Microcosm biofilm was produced on the specimens from a mixture of human and McBain saliva at the first 8h. Enamel samples were then exposed to McBain saliva containing 0.2% sucrose. WSLs formed were characterized by quantitative light-induced fluorescence (QLF) and transverse microradiography (TMR). Data were analyzed by ANOVA/Tukey or Kruskal-Wallis/Dunn tests (p<0.05).
RESULTS
A clear time-response pattern was observed for both analyses, but TMR was able to better discriminate among the lesions. Regarding QLF analysis, median (95%CI; %) changes in fluorescence ∆Z were -7.74(-7.74:-6.45)a, -8.52(-8.75:-8.00)ab, -9.17(-10.00:-8.71)bc, -9.58(-10.53:-8.99)bc and -10.01(-11.44:-9.72)c for 2, 4, 6, 8, and 10 days, respectively. For TMR, median (95%CI; vol%.µm) ∆Z were 1410(1299-1479)a, 2420(2327-2604)ab, 2775(2573-2899)bc, 3305(3192-3406)cd and 4330(3972-4465)d, whereas mean (SD; µm) lesion depth were 53.7(12.3)a, 71.4(12.0)a, 103.8(24.8)b, 130.5(27.2)bc, 167.2(39.3)c for 2, 4, 6, 8 and 10 days, respectively.
CONCLUSION
The progression of WSLs formed on human enamel under microcosm biofilm can be characterized over 2-10 days, both by QLF and TMR analyses, although the latter provides better discrimination among the lesions.
Topics: Biofilms; Dental Caries; Dental Enamel; Humans; Microradiography; Saliva; Tooth Demineralization; Tooth Remineralization
PubMed: 35384988
DOI: 10.1590/1678-7757-2021-0560 -
Journal of Applied Oral Science :... May 2019The aim of this study was to assess the effect of Myracrodruon urundeuva All. and Qualea grandiflora Mart. leaves hydroalcoholic extracts on viability and metabolism of...
Effect of hydroalcoholic extract of Myracrodruon urundeuva All. and Qualea grandiflora Mart. leaves on the viability and activity of microcosm biofilm and on enamel demineralization.
OBJECTIVES
The aim of this study was to assess the effect of Myracrodruon urundeuva All. and Qualea grandiflora Mart. leaves hydroalcoholic extracts on viability and metabolism of a microcosm biofilm and on enamel demineralization prevention.
METHODOLOGY
Microcosm biofilm was produced on bovine enamel using inoculum from pooled human saliva mixed with McBain saliva, under 0.2% sucrose exposure, for 14 days. The biofilm was daily-treated with the extracts for 1 min. At the end, it was analyzed with respect to viability by fluorescence, CFU counting and extracellular polysaccharides (phenol-sulphuric acid colorimetric assay) and lactic acid (enzymatic assay) production. The demineralization was measured by TMR. The data were compared using ANOVA or Kruskal-Wallis (p<0.05).
RESULTS
M. urundeuva All. at 100, 10 and 0.1 μg/mL and Q. grandiflora Mart. at 100 and 0.1 μg/mL reduced biofilm viability similarly to positive control (chlorhexidine) and significantly more than the negative-vehicle control (35% ethanol). M. urundeuva at 1000, 100 and 0.1 μg/mL were able to reduce both lactobacilli and mutans streptococci CFU counting, while Q. grandiflora (1000 and 1.0 μg/mL) significantly reduced mutans streptococci CFU counting. On the other hand, the natural extracts were unable to significantly reduce extracellular polysaccharides and lactic acid productions neither the development of enamel carious lesions.
CONCLUSIONS
The extracts showed antimicrobial properties on microcosm biofilm, however, they had no effect on biofilm metabolism and caries protection.
Topics: Anacardiaceae; Animals; Anti-Infective Agents; Biofilms; Cariostatic Agents; Cattle; Colony Count, Microbial; Dental Enamel; Lactic Acid; Lactobacillus; Male; Microbial Sensitivity Tests; Microbial Viability; Microradiography; Myrtales; Plant Extracts; Plant Leaves; Polysaccharides, Bacterial; Reproducibility of Results; Saliva; Streptococcus mutans; Tooth Demineralization
PubMed: 31166551
DOI: 10.1590/1678-7757-2018-0514