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Oral Surgery, Oral Medicine, and Oral... May 1972
Topics: Decalcification Technique; Dental Pulp; Dental Pulp Capping; Dentin; Dentin, Secondary; Dentinogenesis; Humans; Tooth Calcification; Tooth Permeability
PubMed: 4552855
DOI: 10.1016/0030-4220(72)90451-3 -
Journal of Clinical Laser Medicine &... Feb 2004The purpose of this study was to compare the morphological characteristics of lased dentinal surfaces obtained by chemical etching, which was applied either before or... (Comparative Study)
Comparative Study
OBJECTIVES
The purpose of this study was to compare the morphological characteristics of lased dentinal surfaces obtained by chemical etching, which was applied either before or after laser treatment. The adhesive interface after the application of an adhesive-composite system on the above mentioned dentinal surfaces was also evaluated.
MATERIALS AND METHODS
Eighteen caries-free permanent molars were transversally cut to obtain the dentinal surfaces. Ten of these surfaces were divided into three main groups according to their preparation modality: laser only, laser followed by chemical etching, and chemical etching before laser. The Er:YAG laser was used with two different energy outputs: 200 and 400 mJ at 1 Hz. The eight remaining surfaces were divided into two groups and followed the same preparation as the first three groups. The only difference was a change in frequency: 4 Hz was used for treating these surfaces. An adhesive system (Scotchbond 1, 3M), a thin layer of flowable composite (Tetric Flow, Vivadent), and a regular composite (Z250, 3M) were applied to each dentinal surface and then separately light cured. In order to evaluate the dentine-restoration interface, the samples were cut longitudinally and prepared for SEM observation.
RESULTS
The dentinal surfaces that were etched by the laser treatment did not demonstrate the characteristics necessary for guaranteeing a good bond with the adhesive materials. A closer observation of the dentine-restoration interface revealed some micro-fractures located just below the lased dentinal surface.
CONCLUSION
The decision to use the Er:YAG laser as an alternative to conventional techniques of acid etching is currently arguable. Given that the available adhesive systems require acid conditioning, it would not be advisable to skip this operative step.
Topics: Acid Etching, Dental; Dentin; Dentin-Bonding Agents; Humans; In Vitro Techniques; Low-Level Light Therapy; Microscopy, Electron, Scanning; Molar; Pilot Projects; Resin Cements
PubMed: 15117485
DOI: 10.1089/104454704773660958 -
Archives of Oral Biology Feb 2014Cross-linking of collagen by Advanced Glycation End-products (AGEs) occurs by non-enzymatic glycation (Maillard reaction). The purpose of this study was to examine...
Cross-linking of collagen by Advanced Glycation End-products (AGEs) occurs by non-enzymatic glycation (Maillard reaction). The purpose of this study was to examine whether AGEs are formed in human dentinal collagen, and to consider any possible influence of AGEs on dentinal physiology. Mechanical characteristics, fluorescence spectra and immunohistochemical analyses of demineralized dentine sections from young subjects were compared with those of aged ones. The same investigations were performed with young dentine artificially glycated by incubation in 0.1M ribose solution. Indentation measurement indicated that the sections from aged dentine were mechanically harder than those from young dentine. The hardness of young dentine increased after incubation in ribose solution. Fluorescence peak wavelength of the young dentine was shorter than that of the aged one, but shifted towards the peak wavelength of the aged one after incubation in ribose solution. These changes were considered to be due to accumulation of AGEs. Existence of AGEs in dentinal collagen was confirmed by immunohistochemical analysis. The obtained results suggest that AGEs accumulation occurs in dentinal collagen and is affected by both human age and physiological conditions such as glucose level in blood because dentinal collagen receives nourishment via dental pulp and tubules.
Topics: Adolescent; Adult; Cross-Linking Reagents; Dentin; Female; Fluorescence; Glycation End Products, Advanced; Hardness; Humans; Immunohistochemistry; Maillard Reaction; Male; Microscopy, Electron; Molar, Third
PubMed: 24370182
DOI: 10.1016/j.archoralbio.2013.10.012 -
Scandinavian Journal of Dental Research Oct 1986Demineralized, H-E stained longitudinal and transversal sections of unerupted permanent incisors from 1/2-3-yr-old calves were studied by light microscopy. The most...
Demineralized, H-E stained longitudinal and transversal sections of unerupted permanent incisors from 1/2-3-yr-old calves were studied by light microscopy. The most incisal dentin in all teeth was characterized by a regular pattern of straight axially oriented giant tubules situated in the axiomesiodistal plane with interglobular dentin between them. In younger teeth, the pulpal part of every giant tubule contained an afferent and an efferent blood vessel, forming a hairpin loop and being surrounded by basophil cells. Incisal to the blood vessel loops, cells enbedded in an eosinophil matrix were present in the giant tubule lumina, showing increasing degenerative changes incisally. In older teeth there was a mesiodistally extended eosinophil dentin band near the pulp, with few, irregularly arranged, tortuous dentinal and giant tubules, the latter containing single blood vessels accompanied by pulpal cells. Isolated degenerating odontoblasts in lacunar cavities were seen in the transition area of the normal circumpulpal dentin and the eosinophil dentin band. A hypothesis on the initiation and subsequent development of giant tubules is presented.
Topics: Animals; Cattle; Dentin; Histological Techniques; Incisor
PubMed: 3541147
DOI: 10.1111/j.1600-0722.1986.tb01778.x -
Bulletin Du Groupement International... Jan 1971
Topics: Dental Caries; Dentin; Dentin, Secondary; Humans
PubMed: 5282715
DOI: No ID Found -
East African Medical Journal Dec 1996Dentine hypersensitivity is a common cause of dental pain. The sensitivity has been shown in clinical studies to vary greatly. The response to the treatment of... (Review)
Review
Dentine hypersensitivity is a common cause of dental pain. The sensitivity has been shown in clinical studies to vary greatly. The response to the treatment of hypersensitive teeth varies. It has been observed that while the treatment might be effective in some teeth, it is not so in other teeth. In some hypersensitive teeth spontaneous reduction in the hypersensitivity has been observed, while in other teeth, the sensitivity has persisted even for years. It seems probable that the hydrodynamic mechanism is the one operating in dentine sensitivity and the condition of dentine, with either blocked or open dentinal tubules, is a decisive factor in the degree of dentine sensitivity. In hypersensitive dentine the dentinal tubules are open and the pulp is inflammed. In cases where treatment is effective, probably the dentinal tubules are successfully blocked and the inflammation is resolved. If the process is not successful the teeth will be resistant to treatment. The correct therapeutic approach should aim at blocking the dentinal apertures and resolving pulpal inflammation. In addition, clinicians should be aware of clinical procedures which might result into dentine hypersensitivity.
Topics: Dentin; Dentin Sensitivity; Humans; Inflammation; Nerve Fibers; Risk Factors
PubMed: 9103683
DOI: No ID Found -
Deutsche Zahnarztliche Zeitschrift Dec 1991Electric current produced by corrosion of metals or used for diagnostic or therapeutic purposes has to pass through the dentin to reach the pulp. The electric resistance...
Electric current produced by corrosion of metals or used for diagnostic or therapeutic purposes has to pass through the dentin to reach the pulp. The electric resistance of the dentin, which influences the dentinal current intensity, is poorly documented in the literature. In this study 140 cylindrical dentin samples of human teeth were collected from four different regions of the tooth crown and their specific electrical resistance was measured. The recorded values vary with the orientation of the dentinal tubules ranging between 12.5 ohms and ohms. The linear temperature coefficient of the specific resistance is -0.0132 degrees C-1 for the temperature interval of 20 to 34 degrees C. It is assumed that the mechanism underlying electric conduction in dentin is related to the transport of ions in the dentinal fluid.
Topics: Adult; Corrosion; Dentin; Electric Conductivity; Humans; Middle Aged; Molar, Third
PubMed: 1817891
DOI: No ID Found -
Journal of Dentistry Apr 1994This paper reviews the effect of dentine permeability on the bond strength of dentinal bonding systems and its relationship with the morphology of dentine. Deep dentine... (Review)
Review
This paper reviews the effect of dentine permeability on the bond strength of dentinal bonding systems and its relationship with the morphology of dentine. Deep dentine is more permeable than superficial dentine. Demineralization of dentine surfaces with acidic conditioners significantly increases permeability with respect to dentine covered by a smear layer. Several primers apparently leave intact smear layers as seen by scanning electron microscopy, but greatly increase the fluid filtration towards the dentine suggesting several modifications in the smear layer. Previous generations of dentinal bonding systems have been shown to be extremely sensitive to dentine humidity and permeability. By contrast, contemporary dentine bonding systems are not influenced by wet dentine. According to the Poiseuille-Hagen equation, small changes in the functional diameter of dentinal tubules can greatly modify permeability. Restorative materials are able to reduce the permeability of prepared dentine subject to location.
Topics: Dental Bonding; Dental Leakage; Dentin; Dentin Permeability; Dentin-Bonding Agents; Humans; Humidity; Microscopy, Electron, Scanning; Rheology; Smear Layer; Surface Properties
PubMed: 8195480
DOI: 10.1016/0300-5712(94)90005-1 -
Journal of Oral Rehabilitation Oct 2002The purpose of this study was to study the effect of XeCl excimer laser on smear layer covered dentine of extracted human teeth. Twenty-four freshly extracted human... (Comparative Study)
Comparative Study
The purpose of this study was to study the effect of XeCl excimer laser on smear layer covered dentine of extracted human teeth. Twenty-four freshly extracted human molar teeth were collected and randomly divided into one control group and three experimental groups of six teeth each (groups A-D). The teeth in the experimental groups were irradiated with XeCl 308-nm excimer laser at a fluence of 0.4 J cm-2 and a constant pulse repetition rate of 25 Hz. Group A was used as the control, while groups B, C and D were irradiated at different exposure times of 3, 5 and 7 s, respectively. Subsequently these teeth specimens were subjected to scanning electron microscopic (SEM) examination and energy dispersive X-ray (EDX) spectrometric analysis. The SEM examination revealed melting of the smear layer covered dentin to conceal the underlying dentinal tubules. At a longer exposure time (7 s), dentin melted to form large grains and this resulted in non-uniform closure of underlying dentinal tubules. Under the conditions of this study, it is concluded that the pulsed XeCl 308-nm excimer laser at a fluence of 0.4 J cm-2, with an exposure time of 5 s uniformly occluded exposed smear layer covered dentine with no conspicuous variation in chemical structure.
Topics: Calcium; Chlorine; Dentin; Humans; Laser Therapy; Magnesium; Microscopy, Electron, Scanning; Molar; Phosphorus; Spectrometry, X-Ray Emission; Xenon
PubMed: 12421333
DOI: 10.1046/j.1365-2842.2002.00973.x -
Journal of Dentistry Jan 2017Functionalised silica sub-micron particles are being investigated as a method of delivering antimicrobials and remineralisation agents into dentinal tubules. However,...
OBJECTIVES
Functionalised silica sub-micron particles are being investigated as a method of delivering antimicrobials and remineralisation agents into dentinal tubules. However, their methods of application are not optimised, resulting in shallow penetration and aggregation. The aim of this study is to investigate the impact of cavitation occurring around ultrasonic scalers for enhancing particle penetration into dentinal tubules.
METHODS
Dentine slices were prepared from premolar teeth. Silica sub-micron particles were prepared in water or acetone. Cavitation from an ultrasonic scaler (Satelec P5 Newtron, Acteon, France) was applied to dentine slices immersed inside the sub-micron particle solutions. Samples were imaged with scanning electron microscopy (SEM) to assess tubule occlusion and particle penetration.
RESULTS
Qualitative observations of SEM images showed some tubule occlusion. The particles could penetrate inside the tubules up to 60μm when there was no cavitation and up to ∼180μm when there was cavitation.
CONCLUSIONS
The cavitation bubbles produced from an ultrasonic scaler may be used to deliver sub-micron particles into dentine. This method has the potential to deliver such particles deeper into the dentinal tubules.
CLINICAL SIGNIFICANCE
Cavitation from a clinical ultrasonic scaler may enhance penetration of sub-micron particles into dentinal tubules. This can aid in the development of novel methods for delivering therapeutic clinical materials for hypersensitivity relief and treatment of dentinal caries.
Topics: Acetone; Bicuspid; Biomechanical Phenomena; Dental Occlusion; Dental Pulp Cavity; Dental Scaling; Dentin; Drug Delivery Systems; Humans; Hypersensitivity; Microscopy, Electron, Scanning; Molar; Nanoparticles; Particle Size; Silicon Dioxide; Surface Properties; Ultrasonic Therapy; Ultrasonics; Water
PubMed: 27884720
DOI: 10.1016/j.jdent.2016.11.006