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Lasers in Medical Science Nov 2013The aim of the current investigation was to assess the rate and magnitude of dentin fluid flow of dentinal surfaces irradiated with Er,Cr:YSGG laser. Twenty extracted...
The aim of the current investigation was to assess the rate and magnitude of dentin fluid flow of dentinal surfaces irradiated with Er,Cr:YSGG laser. Twenty extracted third molars were sectioned, mounted, and irradiated with Er,Cr:YSGG laser at 3.5 and 4.5 W power settings. Specimens were connected to an automated fluid flow measurement apparatus (Flodec). The rate, magnitude, and direction of dentin fluid flow were recorded at baseline and after irradiation. Nonparametric Wilcoxon signed ranks repeated measure t test revealed a statistically significant reduction in fluid flow for all the power settings. The 4.5-W power output reduced the flow significantly more than the 3.5 W. The samples showed a baseline outward flow followed by inward flow due to irradiation then followed by decreased outward flow. It was concluded that Er,Cr:YSGG laser irradiation at 3.5 and 4.5 W significantly reduced dentinal fluid flow rate. The reduction was directly proportional to power output.
Topics: Dentin; Dentin Sensitivity; Humans; Hydrodynamics; Lasers, Solid-State; Low-Level Light Therapy; Microscopy, Electron, Scanning; Pilot Projects
PubMed: 23073836
DOI: 10.1007/s10103-012-1218-9 -
Journal of Dentistry Feb 2008To investigate the relationship between the color of carious dentin with varying lesion activity, and bacterial detection in the lesions.
OBJECTIVES
To investigate the relationship between the color of carious dentin with varying lesion activity, and bacterial detection in the lesions.
METHODS
In 26 extracted human molars with coronal dentin caries and four extracted sound human molars, dentin was removed by a round bur every 150 microm from the dentin surface, in the direction of the pulp chamber. Before and after removal, images of nine-color samples and the dentin surface stained with a caries detector dye (1% acid red in propylene glycol) were taken simultaneously by a charge-coupled device (CCD), and dentinal tissue samples were taken with a new round bur. From the images, corrected L*, a* and b* values (CIE 1976 L*a*b* color system) of the dentin surfaces were calculated from the color changes of the nine-color samples. Bacterial DNA in the dentinal tissues was detected by polymerase chain reaction.
RESULTS
Before removal of dentin, the L* of sound molars (L*>50) was significantly larger than that of carious molars (L*<50) (ANOVA, Scheffe's F-test, P<0.05). In addition, the carious molars were divided into type I (a*>20, characteristics of active caries) and type II (a*<20, characteristics of arrested caries), and there was a significant difference in the a* value (P<0.05). For both carious types, the area under the receiver operating characteristic curve of L* was significantly larger than that of a* or b* (univariate Z score test, P<0.05), and the rate of bacterial detection decreased as the L* of dentinal tissue increased, and bacterial DNA was not detected when L* was >60.
CONCLUSIONS
Sound and types I and II carious dentin were discriminated by the combination of L* and a* values of dentinal tissue stained with the caries detector dye before removal of dentin. In carious lesions, the a* values of carious dentin stained with the dye were related to the carious lesion activity before removal of carious tissue, and the L* values were related to the degree of caries progression.
Topics: Bacteria; Color; Colorimetry; DNA, Bacterial; Dental Caries; Dentin; Disease Progression; Fluorescent Dyes; Humans; Image Processing, Computer-Assisted; Photography, Dental; Polymerase Chain Reaction; Rhodamines; Tooth Remineralization
PubMed: 18191886
DOI: 10.1016/j.jdent.2007.11.012 -
Journal of Cranio-maxillo-facial... Jun 2017To evaluate structural and physicochemical characteristics of demineralized human dentin block with increasing demineralization time and to assess new bone formation...
OBJECTIVE
To evaluate structural and physicochemical characteristics of demineralized human dentin block with increasing demineralization time and to assess new bone formation when onlay grafted at different demineralization times in rat calvaria.
STUDY DESIGN
Extracted human permanent teeth were pretreated and demineralized for 10-90 min. Scanning electron microscopy, X-ray diffraction analysis, inductively coupled plasma spectrometry, and energy dispersive X-ray analysis were performed. Demineralized dentin blocks (DDBs) with the representatives of the different demineralization times (10 and 60 min) were implanted in vivo onto rat calvaria (male Sprague-Dawley, n = 20 for each carrier). For controls, collagen sponge and human freeze-dried corticocancellous bone blocks (FDBB) were implanted onto calvaria (n = 20). The rats were sacrificed 2 or 8 weeks postoperatively and evaluated radiographically, histologically, and histomorphometrically.
RESULTS
With increasing demineralization time, the surface structure of dentin blocks showed increased number and size of dentinal tubules. Moreover, the organic components increased, whereas inorganic components decreased. Crystallinity decreased sharply between 10 and 30 min demineralization time. In our in vivo study, at both time points, animals with DDBs showed significantly better bone formation than controls (p < 0.05). The DDB/60 group showed significantly increased new bone area and bone density than the DDB/10 group at 8 weeks (p < 0.05), but showed higher resorption that significantly decreased total augmented area compared with the DDB/10 group (p < 0.05).
CONCLUSION
DDB increased new bone formation and bone density. Further studies are needed to determine the optimal demineralization time to maximize space maintenance and bone formation of the graft material.
Topics: Animals; Bone Density; Dentin; Humans; Male; Microscopy, Electron, Scanning; Osteogenesis; Rats; Rats, Sprague-Dawley; Skull; Spectrometry, X-Ray Emission; Spectrophotometry, Atomic; Surface Properties; Time Factors; Tooth Demineralization; X-Ray Diffraction
PubMed: 28434830
DOI: 10.1016/j.jcms.2017.03.007 -
Talanta Nov 2018The mechanism of coffee eliciting erosion on teeth is unclear as few studies have investigated the direct effect of coffee on enamel and dentin structures. The present...
The mechanism of coffee eliciting erosion on teeth is unclear as few studies have investigated the direct effect of coffee on enamel and dentin structures. The present study identified how coffee, the most popular beverage worldwide, induces staining and erosion on teeth. We show the grade of erosion of molars and incisors in Sprague Dawley rats from two different age groups, young (four weeks) and old (six months). We quantified the concentration of metals contained in coffee by mass spectrometry (ICP-MS). To determine elemental content in enamel (i.e. superficial) and dentin (i.e. substructure), we used Laser-induced Breakdown Spectroscopy (LIBS) and X-ray fluorescence (XRF) spectroscopy, respectively. For LIBS, a significant decrease of Ca, P, and Na was observed in the young coffee group relative to age-matched controls, whereas a significant increase in Mn, Fe, and K was observed. In the old coffee group, a significant increase of Mg, Fe, and K was observed along with a decrease of Mg, Ca, P, Na, Sr and Zn. For XRF, a significant decrease of the Ca/P ratio in the coffee group was observed. Spectroscopy results were correlated with scanning electron microscopy (SEM) and histological analysis. The SEM analysis showed pores and open spaces between young and old coffee groups, respectively. Thinning of enamel layers, loss of continuity in the enamel-dentin-junction, and wide spaces in dentin tubules with coffee use was found histologically. Coffee induces decalcification of teeth that corresponds to erosion, exposing the dentin structure by reducing enamel. Coffee immersion demonstrated an intrinsic staining in dentin by metal deposition.
Topics: Animals; Caffeine; Coffee; Dental Enamel; Dentin; Male; Minerals; Rats; Rats, Sprague-Dawley; Spectrum Analysis
PubMed: 30086959
DOI: 10.1016/j.talanta.2018.07.032 -
Archives of Oral Biology Nov 2006This study examines cross-sections of molar crowns in a diverse modern human sample to quantify variation in enamel thickness and enamel-dentine junction (EDJ) shape.... (Comparative Study)
Comparative Study Review
This study examines cross-sections of molar crowns in a diverse modern human sample to quantify variation in enamel thickness and enamel-dentine junction (EDJ) shape. Histological sections were generated from molars sectioned buccolingually across mesial cusps. Enamel cap area, dentine area, EDJ length, and bi-cervical diameter were measured on micrographs using a digitizing tablet. Nine landmarks along the EDJ were defined, and X and Y coordinates were digitized in order to quantify EDJ shape. Upper molars show greater values for the components of enamel thickness, leading to significantly greater average enamel thickness than in lower molars. Average enamel thickness increased significantly from M1 to M3 in both molar rows, due to significantly increasing enamel cap area in upper molars, and decreasing dentine area in lower molars. Differences in EDJ shape were found among maxillary molars in combined and individual populations. Sex differences were also found; males showed significantly greater dentine area, EDJ length, and bi-cervical diameters in certain tooth types, which resulted in females having significantly thicker average enamel. Differences in enamel thickness and EDJ shape within molars were also found among populations, although few consistent trends were evident. This study demonstrates that enamel thickness and EDJ shape vary among molars, between sexes, and among populations; these factors must be considered in the categorization and comparison of ape and human molars, particularly when isolated teeth or fossil taxa are included. Human relative enamel thickness encompasses most values reported for fossil apes and humans, suggesting limited taxonomic value when considered alone.
Topics: Animals; Dental Enamel; Dentin; Ethnicity; Female; Humans; Male; Mandible; Maxilla; Molar; Odontometry; Paleodontology; Primates; Sex Factors; Tooth Crown
PubMed: 16814245
DOI: 10.1016/j.archoralbio.2006.04.012 -
Journal of Dental Research Feb 1990A longitudinal study of children from ages 7 to 18 showed that, if enamel lesions were included, the overall number was the same in fluoridated and non-fluoridated... (Review)
Review
A longitudinal study of children from ages 7 to 18 showed that, if enamel lesions were included, the overall number was the same in fluoridated and non-fluoridated areas. However, a significant reducing effect of pre-eruptive fluoride could be seen in the number of dentinal lesions in a fluoridated area, provided that fluoride was also consumed post-eruptively for a considerable period of time. A precise estimation of both pre- and post-eruptive effects was obtained when teeth were classified according to their eruption time as related to the onset of water fluoridation. About 66% of the greatest reduction in pit and fissure caries came from pre-eruptive fluoride, while in smooth surfaces, this effect was reduced to 25%. In approximal surfaces, the reduction was due half to pre- and half to post-eruptive fluoride. Post-eruptive fluoride became more important with decreasing severity of caries attack. Thus, assuming a continuing decline in dental caries, the majority of such populations will benefit most from the use of topical fluorides. However, in high-risk groups, supplementation of pre-eruptive fluoride can still be of major importance.
Topics: Child; Dental Caries; Dental Enamel; Dentin; Fluoridation; Humans; Longitudinal Studies; Time Factors; Tooth Eruption
PubMed: 2179337
DOI: 10.1177/00220345900690S145 -
Brazilian Oral Research 2018This study aimed to evaluate the influence of different ethanol concentrations on dentin roughness, surface free energy, and contact angle between AH Plus and the root...
This study aimed to evaluate the influence of different ethanol concentrations on dentin roughness, surface free energy, and contact angle between AH Plus and the root canal dentin. One hundred human maxillary anterior teeth were split longitudinally and 200 dentin specimens were polished to make the surface flatter and smoother. An acrylic bar was positioned between two dentin specimens and impression material was added to create a block, simulating an instrumented root canal space. Specimens were removed from the mold and cleaned in an ultrasonic bath for 10 min. Thereafter, dentin specimens were divided into four groups (n = 50) according to the drying methods used: a) wet: vacuum only, b) paper points: vacuum + absorbent paper points, c) 70% alcohol: 70% alcohol (1 min) + vacuum + absorbent paper points, and d) 100% alcohol: 100% alcohol (1 min) + vacuum + absorbent paper points. A rugosimeter and a goniometer were used to verify the roughness (Ra) and to measure the surface free energy and the contact angle between the AH Plus sealer and the root canal dentin. ANOVA and Tukey tests (α = 0.05) were used for statistical analysis. The 70% and 100% ethanol groups showed significantly decreased roughness as well as increased surface free energy in the root canal dentin when compared to the wet and paper point groups. In addition, ethanol significantly reduced the contact angle between the AH Plus sealer and the root canal dentin. Ethanol solutions (70% and 100%) provide better wettability of AH Plus sealer on dentin surfaces.
Topics: Analysis of Variance; Dental Bonding; Dentin; Epoxy Resins; Ethanol; Humans; Materials Testing; Reproducibility of Results; Root Canal Filling Materials; Surface Properties; Tooth Root; Wettability
PubMed: 29723333
DOI: 10.1590/1807-3107bor-2018.vol32.0033 -
Proceedings of the Finnish Dental... 1992Dentinal sensitivity is a common complaint of patients. Removal of cementum or enamel leaves the dentin exposed allowing various stimuli to produce fluid movement... (Review)
Review
Dentinal sensitivity is a common complaint of patients. Removal of cementum or enamel leaves the dentin exposed allowing various stimuli to produce fluid movement through the dentinal tubules. These fluid movements are believed to activate pulpal sensory nerves leading to pain. Various therapeutic approaches have been investigated to treat this problem. Resins, fluoride compounds and oxalate solutions have been used to block the dentinal tubules. KNO3 and SrCl2 are active ingredients in desensitizing tooth pastes but neither compound reduces the permeability of dentine. The ability of various solutions to decrease hypertonic (3M NaCl) evoked nerve activity was tested in the canine teeth of anesthetized cats. Excitatory and desensitizing solutions were placed into a deep dentinal cavity prepared over the incisal pulp horn. An electrode used to record nerve activity was also placed into this deep cavity. KNO3 and other K+ ion containing solutions elicit a biphasic effect on nerve activity. Immediately following application of these solutions into the deep dentinal cavity there is a brief burst of high frequency spike activity. Following this brief period of excitation, the intradental nerves are silent and respond weakly to hypertonic NaCl. CaCl2 and other divalent cation solutions also inhibit hypertonic NaCl induced nerve activity, but have a weaker effect than that exerted by K+. These observations can be explained based on the effects of various ions on nerve excitability. Increasing the K+ ion concentration in the vicinity of the dentinal nerve terminal depolarize and activates the nerve fibers. Following a prolonged period of depolarization the action potential mechanism is inactivated. Divalent cation solutions stabilize the nerve membrane without changing the membrane potential. Desensitizing solutions do not decrease nerve activity by an effect on pulpal blood flow. This experimental model does not entirely explain the clinical action of these desensitizing agents. The role of inflammation in hypersensitivity and dental pain is currently being investigated.
Topics: Animals; Cations; Dentin; Dentin Sensitivity; Humans; Neurons; Potassium
PubMed: 1508896
DOI: No ID Found -
The Journal of Adhesive Dentistry Aug 2009This in vitro study evaluated the amount and distribution of outward fluid flow that occurred when an experimental etch-and-rinse hydrophobic adhesive was applied to... (Comparative Study)
Comparative Study
PURPOSE
This in vitro study evaluated the amount and distribution of outward fluid flow that occurred when an experimental etch-and-rinse hydrophobic adhesive was applied to ethanol-saturated dentin before and after oxalate pretreatment.
MATERIALS AND METHODS
Measurements of dentin permeability were performed under a constant pulpal pressure of 20 cm H2O in deep and middle dentin. A lucifer yellow solution was placed in the pulp chamber to determine the distribution of the water contamination of the hybrid layers.
RESULTS
The distribution of fluorescence in dentin specimens that were not pretreated with oxalate revealed that the dye permeated around the resin tags and filled the hybrid layer. Dentin specimens pretreated with oxalate prior to resin bonding, showed 80% to 83% less (p < 0.05) water contamination compared to controls. The dentin permeability results obtained before and after oxalate pretreatment showed that oxalate decreased dentin permeability by 98% (p < 0.05) compared to acid-etched controls. This prevented outward fluid movement during bonding, resulting in better resin sealing of dentin due to the formation of a double seal of resin tags over calcium oxalate crystals in the tubules.
CONCLUSION
Outward dentinal fluid flow may contaminate hybrid layers during adhesive bonding procedures. Pretreatment of acid-etched dentin with 3% oxalic acid prior to bonding procedures can prevent outward fluid flow during bonding and water contamination of the hydrophobic hybrid layers.
Topics: Acid Etching, Dental; Calcium Oxalate; Dental Bonding; Dental Pulp Cavity; Dentin; Dentin Permeability; Dentin-Bonding Agents; Dentinal Fluid; Ethanol; Fluorescent Dyes; Humans; Hydrophobic and Hydrophilic Interactions; Isoquinolines; Materials Testing; Microscopy, Confocal; Oxalates; Smear Layer; Solvents; Surface Properties; Water
PubMed: 19701507
DOI: No ID Found -
Oral Surgery, Oral Medicine, Oral... May 2010The purpose of this study was to determine the loss of efficacy over time of the Buc-1 ultrasonic tip in dentin blocks.
OBJECTIVE
The purpose of this study was to determine the loss of efficacy over time of the Buc-1 ultrasonic tip in dentin blocks.
STUDY DESIGN
An ultrasonic handpiece was mounted to the loading arm of a universal testing machine and a downward force of 15 g was applied in 20-sec cycles for a total of 30 min of instrumentation. Efficacy was measured by the change in weight of the dentin block to the nearest 0.01 mg after 2, 10, 20, and 30 minutes of instrumentation (n = 5 tips).
RESULTS
Dentin removal decreased significantly between 2 and 10 minutes of instrumentation with no further significant decrease after 20 or 30 minutes (1-factor analysis of variance: alpha = .05).
CONCLUSION
The evidence suggests there is a significant decrease in dentin removal efficacy of the Buc-1 tip after 10 minutes of instrumentation. Continued instrumentation for up to 30 minutes showed no further decrease in efficacy.
Topics: Dental Materials; Dental Stress Analysis; Dentin; Diamond; Equipment Design; Humans; Materials Testing; Root Canal Preparation; Stress, Mechanical; Time Factors; Ultrasonic Therapy
PubMed: 20416514
DOI: 10.1016/j.tripleo.2009.12.003