1
|
Lau XE, Liu X, Chua H, Wang WJ, Dias M, Choi JJE. Heat generated during dental treatments affecting intrapulpal temperature: a review. Clin Oral Investig 2023; 27:2277-2297. [PMID: 37022531 PMCID: PMC10159962 DOI: 10.1007/s00784-023-04951-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 03/14/2023] [Indexed: 04/07/2023]
Abstract
INTRODUCTION Heat is generated and transferred to the dentine-pulp complex during various dental procedures, such as from friction during cavity preparations, exothermic reactions during the polymerisation of restorative materials and when polishing restorations. For in vitro studies, detrimental effects are possible when intra-pulpal temperature increases by more than 5.5°C (that is, the intra-pulpal temperature exceeds 42.4°C). This excessive heat transfer results in inflammation and necrosis of the pulp. Despite numerous studies stating the importance of heat transfer and control during dental procedures, there are limited studies that have quantified the significance. Past studies incorporated an experimental setup where a thermocouple is placed inside the pulp of an extracted human tooth and connected to an electronic digital thermometer. METHODS This review identified the opportunity for future research and develop both the understanding of various influencing factors on heat generation and the different sensor systems to measure the intrapulpal temperature. CONCLUSION Various steps of dental restorative procedures have the potential to generate considerable amounts of heat which can permanently damage the pulp, leading to pulp necrosis, discoloration of the tooth and eventually tooth loss. Thus, measures should be undertaken to limit pulp irritation and injury during procedures. This review highlighted the gap for future research and a need for an experimental setup which can simulate pulp blood flow, temperature, intraoral temperature and intraoral humidity to accurately simulate the intraoral conditions and record temperature changes during various dental procedures.
Collapse
Affiliation(s)
- Xin Er Lau
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, 310 Great King Street, Dunedin, 9016, New Zealand
| | - Xiaoyun Liu
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, 310 Great King Street, Dunedin, 9016, New Zealand
| | - Helene Chua
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, 310 Great King Street, Dunedin, 9016, New Zealand
| | - Wendy Jingwen Wang
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, 310 Great King Street, Dunedin, 9016, New Zealand
| | - Maykon Dias
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, 310 Great King Street, Dunedin, 9016, New Zealand
| | - Joanne Jung Eun Choi
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, 310 Great King Street, Dunedin, 9016, New Zealand.
| |
Collapse
|
2
|
Witzke K, Frank M, Specht O, Schulz U, Oehlschläger C, Behrend D, Ottl P, Warkentin M. Comparative Sample Preparation Using Focused Ion Beam and Ultramicrotomy of Human Dental Enamel and Dentine for Multimicroscopic Imaging at Micro- and Nanoscale. MATERIALS 2022; 15:ma15093084. [PMID: 35591421 PMCID: PMC9100687 DOI: 10.3390/ma15093084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 04/21/2022] [Accepted: 04/21/2022] [Indexed: 12/04/2022]
Abstract
(1) Background: The aim of this study was to systematically compare TEM sections of mineralized human enamel and dentine prepared by focused ion beam (in situ lift-out) technique and ultramicrotomy through a combination of microscopic examination methods (scanning electron microscopy and transmission electron microscopy). In contrast with published studies, we compared the TEM preparation methods using the same specimen blocks as those for the ultramicrotomy and FIB technique. (2) Methods: A further evaluation of TEM sample preparation was obtained by confocal laser scanning microscopy and atomic force microscopy. In addition, ultramicrotome- and focused ion beam-induced artefacts are illustrated. (3) Results: The FIB technique exposed a major difference between non-decalcified enamel and dentine concerning the ultrastructural morphology compared to ultramicrotome-prepared sections. We found that ultramicrotomy was useful for cutting mineralized dentine, with the possibility of mechanical artefacts, but offers limited options for the preparation of mineralized enamel. FIB preparation produced high-quality TEM sections, showing the anisotropic ultrastructural morphology in detail, with minor structural artefacts. Our results show that the solution of artificial saliva and glutardialdehyde (2.5% by volume) is a very suitable fixative for human mineralized tissue. (4) Conclusions: The protocol that we developed has strong potential for the preparation of mineralized biomaterials for TEM imaging and analysis.
Collapse
Affiliation(s)
- Katharina Witzke
- Department of Oral and Maxillofacial Surgery/Plastic Surgery, Greifswald University Medicine, Ferdinand-Sauerbruch-Straße DZ7, 17475 Greifswald, Germany;
| | - Marcus Frank
- Electron Microscopy Centre, Rostock University Medical Center, Strempelstraße 14, 18057 Rostock, Germany; (M.F.); (U.S.)
- Department of Life, Light and Matter, University of Rostock, Albert-Einstein-Straße 25, 18059 Rostock, Germany; (D.B.); (P.O.)
| | - Olaf Specht
- Department of Material Science and Medical Engineering, University of Rostock, Friedrich-Barnewitz-Straße 4, 18119 Rostock, Germany; (O.S.); (C.O.)
- Institute of Behavioural Physiology, Leibnitz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
| | - Ute Schulz
- Electron Microscopy Centre, Rostock University Medical Center, Strempelstraße 14, 18057 Rostock, Germany; (M.F.); (U.S.)
| | - Claudia Oehlschläger
- Department of Material Science and Medical Engineering, University of Rostock, Friedrich-Barnewitz-Straße 4, 18119 Rostock, Germany; (O.S.); (C.O.)
| | - Detlef Behrend
- Department of Life, Light and Matter, University of Rostock, Albert-Einstein-Straße 25, 18059 Rostock, Germany; (D.B.); (P.O.)
- Department of Material Science and Medical Engineering, University of Rostock, Friedrich-Barnewitz-Straße 4, 18119 Rostock, Germany; (O.S.); (C.O.)
| | - Peter Ottl
- Department of Life, Light and Matter, University of Rostock, Albert-Einstein-Straße 25, 18059 Rostock, Germany; (D.B.); (P.O.)
- Department of Prosthodontics and Materials Sciences, Rostock University Medical Center, Strempelstraße 13, 18057 Rostock, Germany
| | - Mareike Warkentin
- Department of Material Science and Medical Engineering, University of Rostock, Friedrich-Barnewitz-Straße 4, 18119 Rostock, Germany; (O.S.); (C.O.)
- Correspondence: ; Tel.: +49-381-54-345-538
| |
Collapse
|
3
|
Nawrocka A, Piwonski I, Sauro S, Porcelli A, Hardan L, Lukomska-Szymanska M. Traditional Microscopic Techniques Employed in Dental Adhesion Research-Applications and Protocols of Specimen Preparation. BIOSENSORS 2021; 11:bios11110408. [PMID: 34821624 PMCID: PMC8615842 DOI: 10.3390/bios11110408] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/14/2021] [Accepted: 10/18/2021] [Indexed: 06/13/2023]
Abstract
Microscopy is a traditional method to perform ex vivo/in vitro dental research. Contemporary microscopic techniques offer the opportunity to observe dental tissues and materials up to nanoscale level. The aim of this paper was to perform a literature review on four microscopic methods, which are widely employed in dental studies concerning the evaluation of resin-dental adhesive interfaces-confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). The literature search was performed using digital databases: PubMed, Web of Science and Scopus. On the basis of key words relevant to the topic and established eligibility criteria, finally 84 papers were included in the review. Presented microscopic techniques differ in their principle of operation and require specific protocols for specimen preparation. With regard to adhesion studies, microscopy assists in the description of several elements involved in adhesive bonding, as well as in the assessment of the condition of enamel surface and the most appropriate etching procedures. There are several factors determining the quality of the interaction between the substrates which could be recognized and a potential for further implementation of microscopic techniques in dental research could be recognized, especially when these techniques are used simultaneously or combined with spectroscopic methods. Through such microscopy techniques it is possible to provide clinically relevant conclusions and recommendations, which can be easily introduced for enamel-safe bonding and bonding protocols, as well as optimal pretreatments in dentine preparation.
Collapse
Affiliation(s)
- Agnieszka Nawrocka
- Department of General Dentistry, Medical University of Lodz, 251 Pomorska Str., 92-213 Lodz, Poland;
| | - Ireneusz Piwonski
- Department of Materials Technology and Chemistry, Faculty of Chemistry, University of Lodz, 163 Pomorska Str., 90-236 Lodz, Poland;
| | - Salvatore Sauro
- Dental Biomaterials, Preventive and Minimally Invasive Dentistry Departamento de Odontología, Facultad de Ciencias de la Salud, Universidad CEU-Cardenal Herrera C/Del Pozo ss/n, Alfara del Patriarca, 46115 Valencia, Spain;
- Department of Therapeutic Dentistry, I.M. Sechenov First Moscow State Medical University, 119146 Moscow, Russia
| | - Annalisa Porcelli
- Department of Dentistry, Catholic University of the Sacred Heart, 00168 Rome, Italy;
| | - Louis Hardan
- Department of Restorative Dentistry, School of Dentistry, Saint-Joseph University, Beirut 1107 2180, Lebanon;
| | - Monika Lukomska-Szymanska
- Department of General Dentistry, Medical University of Lodz, 251 Pomorska Str., 92-213 Lodz, Poland;
| |
Collapse
|
4
|
Velázquez-López J, Cruz-Gómez MA, Ruelas-Oronia MA, Dipp-Velázquez F, Dib-Kanan A, Méndez-Mancilla Z. Analysis and simulation of heat transfer in human tooth during the curing of orthodontic appliance and food ingestion. APOS TRENDS IN ORTHODONTICS 2016. [DOI: 10.4103/2321-1407.183153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The aim of this study was to analyze and simulate the heat transfer in the human tooth undergoing fixed orthodontic appliances and food intake. An in vivo representative mathematic model of a layered thermographic profile was developed during the LED curing of Gemini bracket 0.022 in slot (conventional ligating system) and Transbond XT adhesive. The characterization of the layered thermic response allowed to identify if during the LED curing process, according to manufacturer’s specification (light curing unit, adhesive) can induce pulpar necrosis. The profile’s thermographic model was the simulation basis of many conditions such as food intake, due to in vivo metrology is affected by the impossibility of a correct apparatus position and the physiologic function of the oral cavity which is exposed to uncontrollable temperature changes. The metrology was carried out with a T-440 thermographic camera during LED curing bracket, using a LED curing light (Elipar S10) placed at 3 ± 1 mm for 5 s at each mesial and distal surface. The thermography outcomes were analyzed in the FLIR Tools Software, Microsoft Excel 2013 and SPSS 22. To adjust the mathematic model error, in vitro studies were performed on third molars for the purpose of realizing extreme exposition temperature condition tests caused by the LED curing unit without jeopardizing the human tooth vitality as would it be on in vivo experimentation. The bracket curing results according to manufacturer’s conditions reached 39°C in vivo temperatures and 47°C on in vitro tests, which does not jeopardize human tooth vitality as said by previous researches, although, an LED curing precise protocol established by the manufacturer’s LED curing light is sustained.
Collapse
Affiliation(s)
- J. Velázquez-López
- Autonomous University of Puebla, Faculty of Stomatology, Stomatology Master of Science in Orthodontics, Graduate Building, Orthodontics Clinic, Puebla, México,
| | - M. A. Cruz-Gómez
- Faculty of Engineering, I.M.E. School, Tribology and Transport Group, Graduate Building, First Floor, Cubicle Num. 16, Valsequillo Blvd., San Claudio Ave., University City, San Manuel Colony, Puebla, México
| | - M. A. Ruelas-Oronia
- Autonomous University of Puebla, Faculty of Stomatology, Stomatology Master of Science in Orthodontics, Graduate Building, Orthodontics Clinic, Puebla, México,
| | - F. Dipp-Velázquez
- Autonomous University of Puebla, Faculty of Stomatology, Stomatology Master of Science in Orthodontics, Graduate Building, Orthodontics Clinic, Puebla, México,
| | - A. Dib-Kanan
- Autonomous University of Puebla, Faculty of Stomatology, Stomatology Master of Science in Orthodontics, Graduate Building, Orthodontics Clinic, Puebla, México,
| | - Z. Méndez-Mancilla
- Autonomous University of Puebla, Faculty of Stomatology, Stomatology Master of Science in Orthodontics, Graduate Building, Orthodontics Clinic, Puebla, México,
| |
Collapse
|
5
|
Contreras-Arriaga B, Rodríguez-Vilchis LE, Contreras-Bulnes R, Olea-Mejìa OF, Scougall-Vilchis RJ, Centeno-Pedraza C. Chemical and morphological changes in human dentin after Er:YAGlaser irradiation: EDS and SEM analysis. Microsc Res Tech 2015; 78:1019-25. [PMID: 26397964 DOI: 10.1002/jemt.22579] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 08/10/2015] [Accepted: 08/16/2015] [Indexed: 11/07/2022]
Abstract
Sixty samples of human dentin were divided into six groups (n = 10) and were irradiated with Er:YAG laser at 100 mJ-19.9 J/cm(2), 150 mJ-29.8 J/cm(2), 100 mJ-35.3 J/cm(2), 150 mJ-53.0 J/cm(2), 200 mJ-70.7 J/cm(2), and 250 mJ-88.5 J/cm(2), respectively, at 7 Hz under a water spray. The atomic percentages of carbon, oxygen, magnesium, calcium, and phosphorus and the Ca-to-P molar ratio on the dentin were determined by energy dispersive X-ray spectroscopy. The morphological changes were observed using scanning electron microscopy. A paired t-test was used in statistical analysis before and after irradiation, and a one-way ANOVA was performed (P ≤ 0.05). The atomic percent of C tended to decrease in all of the groups after irradiation with statistically significant differences, O and Mg increased with significant differences in all of the groups, and the Ca-to-P molar ratio increased in groups IV, V, and VI, with statistically significant differences between groups II and VI. All the irradiated samples showed morphological changes. Major changes in the chemical composition of dentin were observed in trace elements. A significant increase in the Ca-to-P ratio was observed in the higher energy density groups. Morphological changes included loss of smear layer with exposed dentinal tubules. The changes produced by the different energy densities employed could have clinical implications, additional studies are required to clarify them.
Collapse
Affiliation(s)
- Belinda Contreras-Arriaga
- Facultad de Odontología, Centro de Investigación y Estudios Avanzados en Odontología (CIEAO), Universidad Autónoma del Estado de México, Jesús Carranza Esq. Paseo Tollocan, Col. Universidad, Toluca, Estado de México, C.P. 50130, México
| | - Laura Emma Rodríguez-Vilchis
- Facultad de Odontología, Centro de Investigación y Estudios Avanzados en Odontología (CIEAO), Universidad Autónoma del Estado de México, Jesús Carranza Esq. Paseo Tollocan, Col. Universidad, Toluca, Estado de México, C.P. 50130, México
| | - Rosalía Contreras-Bulnes
- Facultad de Odontología, Centro de Investigación y Estudios Avanzados en Odontología (CIEAO), Universidad Autónoma del Estado de México, Jesús Carranza Esq. Paseo Tollocan, Col. Universidad, Toluca, Estado de México, C.P. 50130, México
| | - Oscar Fernando Olea-Mejìa
- Universidad Autónoma Del Estado de México-Universidad Nacional Autónoma de México, Centro Conjunto de Investigación en Química Sustentable (CCIQS), Km 14.5 Carretera Toluca-Ixtlahuaca, San Cayetano de Morelos, Toluca, Estado de México, C.P. 50200, México
| | - Rogelio José Scougall-Vilchis
- Facultad de Odontología, Centro de Investigación y Estudios Avanzados en Odontología (CIEAO), Universidad Autónoma del Estado de México, Jesús Carranza Esq. Paseo Tollocan, Col. Universidad, Toluca, Estado de México, C.P. 50130, México
| | - Claudia Centeno-Pedraza
- Facultad de Odontología, Centro de Investigación y Estudios Avanzados en Odontología (CIEAO), Universidad Autónoma del Estado de México, Jesús Carranza Esq. Paseo Tollocan, Col. Universidad, Toluca, Estado de México, C.P. 50130, México
| |
Collapse
|
6
|
Coutinho E, Cardoso M, Fernandes C, Neves A, Gouvea C, Van Landuyt K, De Munck J, Van Meerbeek B. Nanoleakage Distribution at Adhesive-Dentin Interfaces in 3D. J Dent Res 2011; 90:1019-25. [DOI: 10.1177/0022034511408430] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
In spite of its role in the degradation of tooth-biomaterial interfaces, reports on nanoleakage are largely inconsistent. The aim of this work was to assess nanoleakage patterns qualitatively and quantitatively in 3D, to determine the influence of direction, position, and inclination of the field-of-view. Therefore, we applied a gold-standard 3-step etch-and-rinse adhesive to bur-cut dentin surfaces, after which interface samples were sectioned, infiltrated with an ammoniacal silver-nitrate solution, and embedded by common TEM procedures. High-resolution 3D models of interfaces were then generated by FIB and electron tomography, following strict conditions determined by Monte Carlo simulations. Inverted images in FIB tomography disclosed morphological characteristics analogous to those revealed by TEM. Quantitative analysis revealed large variations in silver-nitrate uptake between 2D image projections in different directions. Furthermore, silver-nitrate fractions in individual 2D image projections were seldom related to the total 3D volumetric fraction. Electron tomography showed that inclination also affected the morphology of silver-nitrate patterns. In conclusion, conventional nanoleakage evaluation is heavily influenced by direction, position, and inclination of the field-of-view, and thus may contain artifacts.
Collapse
Affiliation(s)
- E. Coutinho
- Leuven BIOMAT Research Cluster, Department of Conservative Dentistry, School of Dentistry, Oral Pathology and Maxillo-Facial Surgery, Catholic University of Leuven, Kapucijnenvoer 7, B-3000 Leuven, Belgium, Department of Prosthodontics, School of Dentistry, Fluminense Federal University, Rio de Janeiro, Brazil
| | - M.V. Cardoso
- Leuven BIOMAT Research Cluster, Department of Conservative Dentistry, School of Dentistry, Oral Pathology and Maxillo-Facial Surgery, Catholic University of Leuven, Kapucijnenvoer 7, B-3000 Leuven, Belgium
| | - C.P. Fernandes
- Department of Prosthodontics, School of Dentistry, Fluminense Federal University, Rio de Janeiro, Brazil
| | - A.A. Neves
- Leuven BIOMAT Research Cluster, Department of Conservative Dentistry, School of Dentistry, Oral Pathology and Maxillo-Facial Surgery, Catholic University of Leuven, Kapucijnenvoer 7, B-3000 Leuven, Belgium
| | - C.V.D. Gouvea
- Department of Prosthodontics, School of Dentistry, Fluminense Federal University, Rio de Janeiro, Brazil
| | - K.L. Van Landuyt
- Leuven BIOMAT Research Cluster, Department of Conservative Dentistry, School of Dentistry, Oral Pathology and Maxillo-Facial Surgery, Catholic University of Leuven, Kapucijnenvoer 7, B-3000 Leuven, Belgium
| | - J. De Munck
- Leuven BIOMAT Research Cluster, Department of Conservative Dentistry, School of Dentistry, Oral Pathology and Maxillo-Facial Surgery, Catholic University of Leuven, Kapucijnenvoer 7, B-3000 Leuven, Belgium
| | - B. Van Meerbeek
- Leuven BIOMAT Research Cluster, Department of Conservative Dentistry, School of Dentistry, Oral Pathology and Maxillo-Facial Surgery, Catholic University of Leuven, Kapucijnenvoer 7, B-3000 Leuven, Belgium
| |
Collapse
|
7
|
A review of heat transfer in human tooth—Experimental characterization and mathematical modeling. Dent Mater 2010; 26:501-13. [DOI: 10.1016/j.dental.2010.02.009] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2009] [Revised: 01/04/2010] [Accepted: 02/23/2010] [Indexed: 12/28/2022]
|
8
|
Forner L, Salmerón-Sánchez M, Palomares M, Llena C, Amengual J. The use of atomic force microscopy in determining the stiffness and adhesion force of human dentin after exposure to bleaching agents. J Endod 2009; 35:1384-6. [PMID: 19801235 DOI: 10.1016/j.joen.2009.06.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2009] [Revised: 06/22/2009] [Accepted: 06/29/2009] [Indexed: 10/20/2022]
Abstract
INTRODUCTION Oxidant bleaching agents may induce several alterations on mineralized teeth tissues. Our aim is to study, at the ultrastructural level, mechanical modifications induced on dentin after exposure to different bleaching agents. METHODS Nanoindentation performed with atomic force microscopy was used to measure changes in dentin stiffness as well as the adhesion force between the tip and the tissue both in intertubular and peritubular dentin. For each specimen, dentin localization, and bleaching agent, 100 independent nanoindentations were performed. Carbamide peroxide (30%) and hydrogen peroxide (35%) were used as bleaching agents. RESULTS A significant reduction of both stiffness and adhesion force was found for both carbamide and hydrogen peroxide in peritubular and intertubular dentin. CONCLUSIONS The use of bleaching agents led to a significant reduction in dentin local (at the nanoscale) mechanical properties.
Collapse
Affiliation(s)
- Leopoldo Forner
- Department of Stomatology, Universitat de València, Valencia, Spain.
| | | | | | | | | |
Collapse
|
9
|
NAUMANN M, METZDORF G, FOKKINGA W, WATZKE R, STERZENBACH G, BAYNE S, ROSENTRITT M. Influence of test parameters onin vitrofracture resistance of post-endodontic restorations: a structured review. J Oral Rehabil 2009; 36:299-312. [DOI: 10.1111/j.1365-2842.2009.01940.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
10
|
Zavgorodniy AV, Rohanizadeh R, Swain MV. Ultrastructure of dentine carious lesions. Arch Oral Biol 2007; 53:124-32. [PMID: 17915189 DOI: 10.1016/j.archoralbio.2007.08.007] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2007] [Revised: 08/07/2007] [Accepted: 08/18/2007] [Indexed: 11/29/2022]
Abstract
OBJECTIVE The aim of the present study is to investigate the ultrastructural changes within the different zones of carious dentine and compare those changes with sound dentine. METHODS Transmission electron microscopy and electron diffraction techniques were used to investigate the effect of caries on the inorganic phase of dentine. Areas of interest were identified with optical and scanning electron microscopes. RESULTS The results demonstrated that the intertubular mineral crystallites decrease in size as caries lesion progresses. In the transparent zone of carious lesion, both intratubular and intertubular dentine consisted of nano-size apatetic crystallites with smaller size in the former. The intratubular mineral phase in transparent zone was found to be chemically similar to the intertubular dentin. CONCLUSIONS The study suggests that a 'dissolution and precipitation' mechanism is important in understanding the process of formation of intratubular dentine within the transparent zone induced by caries attack. The observed partial demineralisation of intertubular dentine in transparent zone is discussed in terms of dissolution of tubule microbranches and exposure of intertubular dentin to acids.
Collapse
Affiliation(s)
- Alexander V Zavgorodniy
- Biomaterials Research Unit, Faculty of Dentistry, University of Sydney, 2 Chalmers Street, Surry Hills, NSW 2010, Australia
| | | | | |
Collapse
|
11
|
Carda C, Peydró A. Ultrastructural patterns of human dentinal tubules, odontoblasts processes and nerve fibres. Tissue Cell 2006; 38:141-50. [PMID: 16546231 DOI: 10.1016/j.tice.2006.01.002] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2005] [Revised: 12/26/2005] [Accepted: 01/02/2006] [Indexed: 12/01/2022]
Abstract
The structure of the dentin, consists of the following elements: the odontoblastic processes, dentinal tubules and their periodontoblastic spaces. The odontoblasts are aligned in a single layer in the periphery of the dental pulp and secrete the organic components of dentin. The vitality of dentin is mediated too by the nerve fibres. The ultrastructure of the trigeminal sensory nerves in dentin, especially in relation to odontoblasts remains to be clarified. We studied the third molars and young premolars. The specimens were fixed in glutaraldehyde immediately after extraction. Our investigations give evidence to prove that the distribution of the dentinary tubules is homogeneous, containing a principal odontoblastic prolongation in the regions of the inner dentine, and only in special cases more than one. The area of the dentinary tubules and the odontoblastic prolongations' area were studied. The nervous fibres appeared accompanying 30-70% of the odontoblastic prolongations and their synapsis-like relation with the odontotoblastic processes was demonstrated. The existence of very few periodontoblastic spaces, and intradentinal sensory axons, as well as the intercellular connections will allow us to discover more about the mechanisms of the dentinary permeability, and its significance in maintenance and repair of the human pulpodentinal complex.
Collapse
Affiliation(s)
- C Carda
- Department of Pathology, Medical School, University of Valencia, Valencia, Spain.
| | | |
Collapse
|
12
|
Porter AE, Nalla RK, Minor A, Jinschek JR, Kisielowski C, Radmilovic V, Kinney JH, Tomsia AP, Ritchie RO. A transmission electron microscopy study of mineralization in age-induced transparent dentin. Biomaterials 2005; 26:7650-60. [PMID: 16005961 DOI: 10.1016/j.biomaterials.2005.05.059] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2005] [Accepted: 05/17/2005] [Indexed: 11/24/2022]
Abstract
It is known that fractures are more likely to occur in altered teeth, particularly following restoration or endodontic repair; consequently, it is important to understand the structure of altered forms of dentin, the most abundant tissue in the human tooth, in order to better define the increased propensity for such fractures. Transparent (or sclerotic) dentin, wherein the dentinal tubules become occluded with mineral as a natural progressive consequence of aging, is one such altered form. In the present study, high-resolution transmission electron microscopy is used to investigate the effect of aging on the mineral phase of dentin. Such studies revealed that the intertubular mineral crystallites were smaller in transparent dentin, and that the intratubular mineral (larger crystals deposited within the tubules) was chemically similar to the surrounding intertubular mineral. Exit-wave reconstructed lattice-plane images suggested that the intratubular mineral had nanometer-size grains. These observations support a "dissolution and reprecipitation" mechanism for the formation of transparent dentin.
Collapse
Affiliation(s)
- Alexandra E Porter
- Lawrence Berkeley National Laboratory, National Center for Electron Microscopy, Berkeley CA 94720, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Nalla RK, Porter AE, Daraio C, Minor AM, Radmilovic V, Stach EA, Tomsia AP, Ritchie RO. Ultrastructural examination of dentin using focused ion-beam cross-sectioning and transmission electron microscopy. Micron 2005; 36:672-80. [PMID: 16182542 DOI: 10.1016/j.micron.2005.05.011] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2005] [Revised: 05/16/2005] [Accepted: 05/19/2005] [Indexed: 11/19/2022]
Abstract
Focused ion-beam (FIB) milling is a commonly used technique for transmission electron microscopy (TEM) sample preparation of inorganic materials. In this study, we seek to evaluate the FIB as a TEM preparation tool for human dentin. Two particular problems involving dentin, a structural analog of bone that makes up the bulk of the human tooth, are examined. Firstly, the process of aging is studied through an investigation of the mineralization in 'transparent' dentin, which is formed naturally due to the filling up of dentinal tubules with large mineral crystals. Next, the process of fracture is examined to evaluate incipient events that occur at the collagen fiber level. For both these cases, FIB-milling was able to generate high-quality specimens that could be used for subsequent TEM examination. The changes in the mineralization suggested a simple mechanism of mineral 'dissolution and reprecipitation', while examination of the collagen revealed incipient damage in the form of voids within the collagen fibers. These studies help shed light on the process of aging and fracture of mineralized tissues and are useful steps in developing a framework for understanding such processes.
Collapse
Affiliation(s)
- R K Nalla
- Materials Sciences Division, Lawrence Berkeley National Laboratory, and Department of Materials Science and Engineering, University of California, Berkeley, CA 94720, USA
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Abstract
BACKGROUND Nanodentistry will make possible the maintenance of comprehensive oral health by involving the use of nanomaterials, biotechnology (including tissue engineering) and, ultimately, dental nanorobotics (nanomedicine). RESULTS When the first micrometer-sized dental nanorobots can be constructed within 10 to 20 years, these devices will allow precisely controlled oral analgesia, dentition replacement therapy using biologically autologous whole replacement teeth manufactured during a single office visit, and rapid nanometer-scale precision restorative dentistry. CLINICAL IMPLICATIONS New treatment opportunities may include dentition renaturalization, permanent hypersensitivity cure, complete orthodontic realignments during a single office visit, covalently bonded diamondized enamel and continuous oral health maintenance through the use of mechanical dentifrobots.
Collapse
|