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Journal of Clinical Periodontology Jul 1983The exposure of cervical dentine has a multifactorial aetiology and pain may frequently be elicited by a number of stimuli. Management of the condition, dentine... (Review)
Review
The exposure of cervical dentine has a multifactorial aetiology and pain may frequently be elicited by a number of stimuli. Management of the condition, dentine hypersensitivity, tends to be empirical because of the lack of knowledge concerning the mechanism of pain transmission through dentine. The pulpal changes associated with the condition and any modulating effect on symptoms are by no means clearly established. Evidence suggests that exposed dentine which is sensitive exhibits patent tubules. The question of how pain is initiated across the dentine has received considerable attention but still remains somewhat debatable. The literature reviewed indicates that, at most, nerve fibres only penetrate a limited distance along some dentinal tubules. The theories that either the odontoblasts and their processes act as dentinal receptors or the nerves in the pulp are the pain receptors, are discussed. Evidence for the stimulation of pulp nerve fibres by a hydrodynamic mechanism would appear the most likely mechanism. Nevertheless, whichever theory proves to be correct, occlusion of dentinal tubules would appear an essential prerequisite for an effective desensitising agent.
Topics: Dentin; Dentin Sensitivity; Humans; Nerve Fibers; Pain; Synaptic Transmission
PubMed: 6309917
DOI: 10.1111/j.1600-051x.1983.tb01283.x -
Stoma Sep 1952
Topics: Dentin; Humans
PubMed: 13005265
DOI: No ID Found -
Journal of Medical and Dental Sciences Mar 2008Recently, improvement of the properties of dentin surface using dental lasers to increase bonding strength has been anticipated in the field of adhesive dentistry. The...
Recently, improvement of the properties of dentin surface using dental lasers to increase bonding strength has been anticipated in the field of adhesive dentistry. The objective of this study was to investigate changes in the surface properties of human dentin after ArF excimer laser irradiation at different irradiation times, pulse repetition rates and energy densities. The SEM images of the irradiated surfaces were observed, and the contact angle and the roughness of the irradiated surface were measured. As a result, SEM demonstrated that the dentin surface became irregular following ArF excimer laser irradiation. When the energy density increased, the irregularity became more minute and dentinal tubules were more easily identified. By contrast, such changes were not observed when the irradiation time and pulse repetition rate were changed. Moreover, as energy densities increased, the contact angle tended to decrease and the surface roughness tended to increase. These results suggested that the area of the irradiated surface and wettability increased after irradiation with the ArF excimer laser. Consequently, irradiation with ArF excimer lasers could improve the surface properties and be potentially useful for adhesive dentistry.
Topics: Dental Etching; Dentin; Humans; Lasers, Excimer; Microscopy, Electron, Scanning; Molar, Third; Surface Properties; Wettability
PubMed: 19845161
DOI: No ID Found -
Journal of Endodontics Dec 2017The objective of this study was to compare the methods of micro-computed tomography (micro-CT) and cross-sectioning followed by stereomicroscopy in assessing dentinal... (Comparative Study)
Comparative Study
INTRODUCTION
The objective of this study was to compare the methods of micro-computed tomography (micro-CT) and cross-sectioning followed by stereomicroscopy in assessing dentinal defects after instrumentation with different mechanized systems.
METHODS
Forty mesial roots of mandibular molars were scanned and divided into 4 groups (n = 10): Group R, Reciproc; Group PTN, ProTaper Next; Group WOG, WaveOne Gold; Group PDL, ProDesign Logic. After instrumentation, the roots were once again submitted to a micro-CT scan, and then sectioned at 3, 6, and 9 mm from the apex, and assessed for the presence of complete and incomplete dentinal defects under a stereomicroscope. The nonparametric Kruskal-Wallis, Friedman, and Wilcoxon tests were used in the statistical analysis. The study used a significance level of 5%.
RESULTS
The total number of defects observed by cross-sectioning followed by stereomicroscopy was significantly higher than that observed by micro-CT, in all of the experimental groups (P ≤ .05). All of the defects identified in the postoperative period were already present in the corresponding preoperative period. There was no significant difference among the instrumentation systems as to the median numbers of defects, for either cross-sectioning followed by stereomicroscopy or micro-CT, at all the root levels (P > .05). In the micro-CT analysis, no significant difference was found between the median numbers of pre- and postinstrumentation defects, regardless of the instrumentation system (P > .05).
CONCLUSION
None of the evaluated instrumentation systems led to the formation of new dentin defects. All of the defects identified in the stereomicroscopic analysis were already present before instrumentation, or were absent at both time points in the micro-CT analysis, indicating that the formation of new defects resulted from the sectioning procedure performed before stereomicroscopy and not from instrumentation.
Topics: Dental Instruments; Dentin; Humans; Root Canal Preparation; X-Ray Microtomography
PubMed: 29033087
DOI: 10.1016/j.joen.2017.07.015 -
Nichidai Koku Kagaku = Nihon University... Jun 1989The teeth of dogs in which the root dentin was incompletely formed were prepared so that dentin was exposed. Tetracycline was then injected and the teeth were studied...
The teeth of dogs in which the root dentin was incompletely formed were prepared so that dentin was exposed. Tetracycline was then injected and the teeth were studied for dentin formation after the periods of 18, 20, 48 and 76 weeks. After the dentin was exposed slightly, reparative secondary dentin was not formed in the pulp horn area; However, a considerable amount of dentin was formed at the walls of the pulp chambers and the root canals. No changes were noted in the pulp horn area in the prepared teeth in comparison with unprepared teeth. The results imply that dentinal changes in the pulp horn area caused by dentinal cutting are more closely related to the depth of dentinal preparation than to the age of the tooth and to the elapsed time after preparation.
Topics: Animals; Dentin; Dentin, Secondary; Dogs; Tetracycline; Tooth Root
PubMed: 2626164
DOI: No ID Found -
Archives of Oral Biology 1994Recent studies indicate that intradental A-type nerve fibres are responsible for the sensitivity of dentine and are activated by fluid movements in dentinal tubules... (Review)
Review
Recent studies indicate that intradental A-type nerve fibres are responsible for the sensitivity of dentine and are activated by fluid movements in dentinal tubules (hydrodynamic mechanism). The patency of the tubules affects dentine sensitivity to a great extent. Both A delta- and A beta-type nerve fibres respond to dentinal (hydrodynamic) stimulation in a similar way. Only a few studies have been made on the regional sensitivity of dentine or the receptive areas of intradental nerve fibres. The results indicate that the fibres innervating different parts of coronal dentine are equally sensitive to dentinal stimulation but those in the cervical area may be less responsive. Inflammation in the pulp can considerably alter dentine sensitivity. In dog teeth with chronically exposed dentine, nerve responses to hydrodynamic stimulation were reduced although other functional changes indicated nerve sensitization. This may be due to spontaneously occurring changes in the exposed dentine that block the tubules. In acute experiments on cat and dog teeth with open dentinal tubules, certain inflammatory mediators increase the sensitivity of the responding nerve fibres. It seems that intradental C-fibres do not respond to hydrodynamic stimulation of dentine. They are polymodal and activated when external stimuli reach the pulp proper. They could perhaps mediate the dull pain connected with pulpitis. However, they might also have an important modifying effect on dentine sensitivity because they can release neuropeptides, which function in the inflammatory reactions.
Topics: Animals; Dental Pulp; Dentin; Dentin Sensitivity; Humans; Nerve Fibers; Neuropeptides; Pulpitis
PubMed: 7702462
DOI: 10.1016/0003-9969(94)90184-8 -
Photomedicine and Laser Surgery Dec 2004The purpose of this in vitro study was to verify the efficacy of Nd:YAG pulsed laser at 1064 nm in sealing dentinal tubules in vitro, with its resulting morphological...
OBJECTIVE
The purpose of this in vitro study was to verify the efficacy of Nd:YAG pulsed laser at 1064 nm in sealing dentinal tubules in vitro, with its resulting morphological changes using clinical parameters applicable to the treatment of dentin hypersensitivity.
BACKGROUND DATA
Although many papers have been written on the subject, no rapid, efficient, and long-lasting treatment for this problem has been developed.
MATERIALS AND METHODS
Twenty healthy extracted human teeth were kept in saline solution. Cervical cement was removed with a no. 57FG bur to expose approximately 4 mm(2) of dentin. Two groups were in the buccal aspect (A and B-irradiated) and one group in the lingual aspect (C-control not irradiated) of the same tooth. Samples with a remaining dentinal thickness between 1 and 1.5 mm were selected. Irradiation parameters were 30 mJ, 0.3W(Group A) and 40 mJ, 0.4 W(Group B); 7 Hz was used in both groups in two 43-sec applications each, with a 10-sec interval. In 10 samples, the dentinal surface underwent SEM examination for study. The other 10 remaining irradiated samples were centrally cleaved to study laser penetration depth in dentin (SEM).
RESULTS
Obliteration of dentinal tubule openings and solidification of the dentin surface were observed in all irradiated samples. Laser penetration depth in dentin (SEM) varied from 1 to 7 microm, depending on irradiation parameters used in each group.
CONCLUSION
We concluded that the use of the Nd:YAG laser was a very effective measure for obliterating dentinal tubule openings.
Topics: Dentin; Humans; Laser Therapy; Molar
PubMed: 15684756
DOI: 10.1089/pho.2004.22.527 -
Journal of Dentistry Jan 1999This paper reviews the evidence for dentine's permeability in order to clarify and emphasize its confounding effect on leakage test measurements, and hence the need to... (Review)
Review
OBJECTIVES
This paper reviews the evidence for dentine's permeability in order to clarify and emphasize its confounding effect on leakage test measurements, and hence the need to use special test designs to avoid its effects.
METHODS
The literature on the subject between 1887 and 1997, including 249 articles.
CONCLUSIONS
The prerequisite condition for any tracer penetration test is that unflawed specimens are themselves impermeable to tracer. Entry of tracer then can be used to indicate correctly the location or severity of flaws. The relative impermeability of intact dental enamel permits such testing of the enamel-restoration interface seal, but the same is not true when using dentine, which is usually frankly porous to most tracers through its tubules. False positive results are very likely. Recent intense interest in dentine bonding agents has increased the need and frequency of these tests with dentine, but this serious confounding factor has so far generally remained unstated, and has only been controlled adequately in one study. If tracer penetration test results are to be meaningful, then adequate control is required.
Topics: Animals; Dental Leakage; Dentin; Dentin Permeability; Humans; Surface Properties
PubMed: 9922606
DOI: 10.1016/s0300-5712(98)00038-4 -
Journal of Biomedical Materials... Mar 2004The objective of this study was to determine the influence of dissolved dentinal substances in demineralized dentin on the hybridization of resin for bonding to dentin....
The objective of this study was to determine the influence of dissolved dentinal substances in demineralized dentin on the hybridization of resin for bonding to dentin. It was hypothesized that these substances, including polyelectrolytes, significantly change the substrates, which could then be assessed by the addition of Na(+), Ca(2+), or Fe(3+) in 10% phosphoric acid. Bovine dentin specimens were etched for 10 s with a solution of 10% phosphoric acid (control) or of 22.0 mM dissolved sodium chloride (10P-Na), calcium chloride (10P-Ca), or ferric chloride (10P-Fe). The specimens were then rinsed, blot-dried, and primed three times with 5% 4-methacryloyloxyethyl trimellitate anhydride in acetone for 60 s. Methyl methacrylate-tri-n-butylborane resin was then applied. The tensile bond strength of each of the dumbbell-shaped specimens was then measured. The fractured surfaces and modified cross-sections were examined by scanning electron microscopy. The cross-sections were soaked in 6N HCl for 10 s and then in 1% sodium hypochlorite for 30 min to determine the resin content in the hybridized specimens. Shrinkage of the demineralized dentins upon drying was assessed by atomic force microscopy. The tensile bond strengths were 10.8 +/- 4.5 (control), 15.0 +/- 7.0 (10P-Na), 19.3 +/- 5.5 (10P-Ca), and 27.8 +/- 8.1 (10P-Fe) MPa. The atomic force microscopy studies showed that Fe(3+) minimized the shrinkage by drying for 10 s but Ca(2+) and Na(+) did not decrease the shrinkage the same as the control. The results support the hypothesis that the monomer permeability of wet demineralized dentin is effectively improved by dissolving ferric ions in the phosphoric acid, resulting in a greater bond strength and higher resin content in the hybridized dentin. The dissolved dentinal substances, including the polyelectrolytes, had a significant influence on the characteristics of the demineralized dentin, changing the degree of hybridization and bonding.
Topics: Animals; Boron Compounds; Cattle; Chlorides; Dental Bonding; Dental Materials; Dentin; Ferric Compounds; Ions; Materials Testing; Methylmethacrylates; Microscopy, Atomic Force; Microscopy, Electron, Scanning; Phosphoric Acids; Tensile Strength
PubMed: 14762937
DOI: 10.1002/jbm.a.20106 -
Journal of Dental Research Jan 1978Dentinal pain in connection with mechanical stimulation i.e. probing, chiseling and initial drilling may be due to removal of fluid from the dentinal tubules. Loss of... (Comparative Study)
Comparative Study
Dentinal pain in connection with mechanical stimulation i.e. probing, chiseling and initial drilling may be due to removal of fluid from the dentinal tubules. Loss of fluid due to "normal" evaporation from exposed dentin may produce an outward flow in the dentinal tubules rapid enough to cause pain and within a few minutes odontoblast aspiration.
Topics: Capillary Action; Cell Nucleus; Child; Dentin; Desiccation; Humans; Odontoblasts; Pain; Sensation; Water
PubMed: 277500
DOI: 10.1177/00220345780570012001