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Tooth Substance (tooth + substance)
Selected AbstractsAbfraction Lesions: Myth or Reality?JOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 5 2003J.S. REES BDS ABSTRACT Loss of tooth substance in the cervical region is usually attributed to toothbrush abrasion, erosion, or a combination of both factors. Recently the role of occlusal loading has become increasingly prominent. It is suggested that high occlusal loads cause large cervical stress concentrations, resulting in a disruption of the bonds between the hydroxyapatite crystals and the eventual loss of cervical enamel. This process has been called noncarious cervical tooth loss or abfraction. This article reviews the available evidence to support the thesis that occlusal loading can contribute to the process of abfraction. It also reviews the potential interactions between occlusal loading and erosion that may contribute to abfraction lesion formation. CLINICAL SIGNIFICANCE It is important to recognize the potential role of occlusal loading in the loss of cervical tooth tissue so that management of the occlusion can be incorporated into a treatment plan for a patient with abfraction lesions. [source] A comparison of root surface instrumentation using two piezoelectric ultrasonic scalers and a hand scaler in vivoJOURNAL OF PERIODONTAL RESEARCH, Issue 1 2007H. Kawashima Background and Objective:, This study compared the effectiveness of two piezoelectric ultrasonic scalers and a hand scaler for subgingival scaling and root planing in vivo. Material and Methods:, Fifteen patients with advanced periodontal disease and with teeth scheduled for extraction were selected for this study. Three experimental groups of 10 teeth each were treated with one of two piezoelectric ultrasonic scalers [VectorÔ scaler and Enac® scaler] or with a hand scaler. Instrumentation was continued until the root surface felt hard and smooth to an explorer tip. The root surface characteristics after instrumentation were examined using scanning electron microscopy, and the amount of remaining calculus, roughness and loss of tooth substance were estimated using the remaining calculus index and roughness loss of tooth substance index. Results:, The remaining calculus index did not differ significantly among the three groups. The roughness loss of tooth substance index was significantly lower for the VectorÔ scaler and Enac® scaler groups than for the hand scaler group and also differed significantly between the VectorÔ scaler and Enac® scaler groups. Conclusion:, This study suggests that the VectorÔ scaler produces a smooth root surface with minimal loss of tooth substance. It is a reasonable choice for gentle periodontal maintenance treatment. [source] Functional mapping of carious enamel in human teeth with Raman microspectroscopyJOURNAL OF RAMAN SPECTROSCOPY, Issue 5 2008H. Kinoshita Abstract We employed Raman microspectroscopy to measure the Raman spectra of phosphate in sound and carious tooth substance. The peak intensity at 960 cm,1 of the phosphate (PO43,) symmetric stretching vibrational mode (,1) in sound enamel was stronger than that of sound dentin, which indicated that sound enamel contained more phosphate than sound dentin. Furthermore, the element analysis of phosphate in sound teeth substance, measured using a scanning electron microscope (SEM) equipped with an energy dispersive X-ray spectroscope (EDX), gave similar results to those of the Raman measurement. In addition, the border between sound enamel and dentin was clearly demonstrated by mapping the image of the Raman spectrum of phosphate. The mapping image of phosphate in the carious enamel region revealed a heterogeneous low Raman spectrum intensity of phosphate in the area surrounding carious enamel; this finding indicates that phosphate had dissolved from the tooth substance in such areas. In contrast with the decrease in the Raman spectrum intensity of phosphate, the intensity of amide I increased mainly in the low-phosphate area. Although it remains very difficult to clinically identify the accurate border between sound and carious tooth substance, this distinction may be enabled by using the Raman spectrum of carious tooth substance. Copyright © 2008 John Wiley & Sons, Ltd. [source] Determination of the dynamics of restored teeth by 3D electronic speckle pattern interferometry,LASERS IN SURGERY AND MEDICINE, Issue 4 2004H. Lang Abstract Background and Objectives The difficulties typically encountered in studying the effects of restorations on tooth reinforcement are often due to the 3-dimensional (3D) nature of deformation. Therefore, electronic 3D-Speckle-Interferometry (3D-ESPI) was used to assess the impact of different restorative materials on the deformation of teeth. Study Design/Materials and Methods Small and large MOD-preparations in extracted premolars were restored with gold inlays, ceramic inlays, composite resin inlays, amalgam, or composite resin. The restorations and cusps were loaded (90 N) and the deformation was assessed by 3D-ESPI. Results Teeth with small restorations were deformed only slightly and the differences between the materials were minimal (P>0.05). In contrast, teeth with large restorations displayed material-specific deformation patterns: (a) all materials led to decreased deformation as compared with unfilled teeth, (b) elastic materials caused only local deformation, (c) non-adhesive materials resulted in translation of the restoration and marginal discrepancies, (d) adhesive inlays brought about increased deformation of the luting resin composite, (e) loading of the cusps caused higher deformation than loading of the restorations, and (f) bonded restorations stabilized the cusps. Conclusions The results show that the deformation pattern of restored teeth is material-specific but the extent of deformation is primarily limited by the remaining tooth substance. Lasers Surg. Med. 34:300,309, 2004. © 2004 Wiley-Liss, Inc. [source] Abfraction: separating fact from fictionAUSTRALIAN DENTAL JOURNAL, Issue 1 2009JA Michael Abstract Non-carious cervical lesions involve loss of hard tissue and, in some instances, restorative material at the cervical third of the crown and subjacent root surface, through processes unrelated to caries. These non-carious processes may include abrasion, corrosion and possibly abfraction, acting alone or in combination. Abfraction is thought to take place when excessive cyclic, non-axial tooth loading leads to cusp flexure and stress concentration in the vulnerable cervical region of teeth. Such stress is then believed to directly or indirectly contribute to the loss of cervical tooth substance. This article critically reviews the literature for and against the concept of abfraction. Although there is theoretical evidence in support of abfraction, predominantly from finite element analysis studies, caution is advised when interpreting results of these studies because of their limitations. In fact, there is only a small amount of experimental evidence for abfraction. Clinical studies have shown associations between abfraction lesions, bruxism and occlusal factors, such as premature contacts and wear facets, but these investigations do not confirm causal relationships. Importantly, abfraction lesions have not been reported in pre-contemporary populations. It is important that oral health professionals understand that abfraction is still a theoretical concept, as it is not backed up by appropriate clinical evidence. It is recommended that destructive, irreversible treatments aimed at treating so-called abfraction lesions, such as occlusal adjustment, be avoided. [source] | ||||||||||