Unit:
Βιβλιοθήκη ΟδοντιατρικήςΤομέας Βασική Επιστήμη Βιολογίας Στόματος
Dissertation committee:
Ευαγγελία Παπαγιαννούλη, Ομότιμη Καθηγήτρια, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Γεώργιος Ηλιάδης, Καθηγητής, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Αφροδίτη Κακάμπουρα, Καθηγήτρια, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Γεώργιος Βουγιουκλάκης, Ομότιμος Καθηγητής, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Γεώργιος Μουντούρης, Αναπληρωτής Καθηγητής, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Σπύρος Ζηνέλλης, Αναπληρωτής Καθηγητής, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Σωτηρία Γκιζάνη, Επίκουρη Καθηγήτρια, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Original Title:
Συγκριτική μελέτη της κλινικής συμπεριφοράς τριών εμφρακτικών υλικών σε αποκαταστάσεις ΙΙης ομάδας νεογιλών δοντιών - Μελέτη ανάκτησης
Translated title:
Comparative evaluation on the performance of three different materials in Class II restorations in primary molars - a retrieval analysis study
Summary:
Introduction: Dental materials tend to reduce their success rates in primary than in permanent teeth due to the morphologic and size differences of the primary teeth, their higher extent of attrition and the lack of cooperation of young children in certain cases that can affect their clinical behavior.
Αim: The purpose of this study was to evaluate comparatively the performance of three different materials (amalgam, composite resin and polyacid modified resin composites) in Class II restorations in retrieved primary molars.
Materials and method: The material of this study consisted of primary molars that have been naturally exfoliated and had been treated with Class II restorations with the following materials: amalgam (Dispersalloy, DeTrey/Dentsply, Konstanz, GER), resin composite (Spectrum, DeTrey/Dentsply), and polyacid modified resin composite (Dyract, DeTrey/Dentsply). Twenty restorations of each material were examined. The restored teeth derived from two clinical studies of the Department of Pediatric Dentistry of the University of Athens. All restorations were performed by four pediatric dentists οn primary carious lesions extending to dentin, in vital first and second primary molars that required Class II cavity preparations. The restorative protocol for each type of restorative material was predetermined. Instructions were given to both parents and children to store the restored teeth after the exfoliation in tap water and in room temperature, marking the date of exfoliation, and to hand them over to the pediatric dentists as soon as possible. After the collection, teeth were sectioned at a proximal-distal direction with a hard tissue microtome and evaluated for the following: a) Morphologic and structural relationship of material-cavity wall interfaces; b) presence of secondary caries; c) dental tissue characteristics adjacent to the cavities, and d) elemental and molecular distributions along the interfaces in the presence or absence of demineralization. The study involved the following instrumentation: a) Reflected light optical microscopy; b) computerized X-ray microtomography; c) reflection FTIR microscopy and molecular mapping and d) scanning electron microscopy and X-ray microanalysis. Statistical analysis was performed with the nonparametric method Kruskal-Wallis One Way ANOVA on Ranks. The results of interfacial lesions, hard surface deposits and marginal overhangs were investigated with Dunn's Method multiple comparison test at α=0.05 significance level.
The statistical analysis of the percentage reduction of calcification was conducted by One way ANOVA and Tukey’s multiple comparison test at α=0.05 significance level. Statistical analyses were performed using Sigma Stat software.
Results: Optical microscopy demonstrated higher rate of marginal debonding and defects in Dyract restorations compared to Spectrum TPH. No significant differences were found in the extent of interfacial lesions, hard surface deposits and marginal overhangs. Computerized X-ray microtomography revealed bulk porosity and interfacial defects, mainly on the axial and cervical cavity walls mainly on Dyract. Spectrum TPH showed significantly lower porosity and some defects probably because of fractures in cervical enamel. FTIR microscopy showed a reduction in the mineral to matrix ratio in the dentin lesions adjacent to Dyract restorations implying greater decalcification. In the presence of resin liners, interfacial gaps were observed due to the debonding of the liners from dentin. Dispersalloy and Spectrum TPH showed lower degree of subsurface decalcification than Dyract. Elemental X-ray mapping failed to disclose development of elemental migration or diffusion gradients at the dentin-restoration interfaces. However, Dispersalloy restorations showed an extended diffusion pattern of Zn in dentin, even at a large distance from the material-dentin interface without detecting other elements of amalgam, including Ag. The mechanism of the selective permeation of Zn in such great depth is unknown, apparently through the dentine tubules, nor of the biological role. However, it is known that Zn is the strongest antimicrobial agent in terms of the elemental composition of dental materials.
Clinical Significance: Marginal debonding and defects differences may imply variations in microleakage to the oral environment. Despite the similar levels of interfacial lesions, hard surface deposits and marginal overhangs, those parameters indicate different sensitivity and tooth discoloration. Bulk porosity, interfacial defects and the percentage of decalcification have revealed limited mechanical and physical properties of material and durability.
Main subject category:
Health Sciences
Keywords:
Filling materials, Class II, Primary molars, Retrieval analysis
Number of references:
226
