Influence of application site of provisional cement on the marginal adaptation of provisional crowns

Mayra Cardoso,Mariana Ribeiro De Moraes Rego,Luiz Carlos Santiago,Marcelo Ferreira Torres

doi:10.1590/s1678-77572008000300010

Mayra Cardoso, Mariana Ribeiro De Moraes Rego + Show 2 more

Open Access

https://doi.org/10.1590/s1678-77572008000300010

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Abstract

Introduction: Marginal discrepancies may lead to cement washout and marginal leakage, damaging periodontal and pulp tissues or causing premature loss of the restoration. Purpose: This study evaluated the influence of application site of provisional cement on the marginal adaptation of provisional crowns. Material and Methods: Four different application sites of provisional cement (Temp Bond NE, Kerr Corporation) were used for cementation of provisional crowns on phantom teeth prepared for full crown restorations, performing 4 experimental groups (n=10): cement applied to all internal surfaces of the crown (CAO); cement applied to all internal surfaces of the crown, except for the occlusal surface (CA); cement applied to the cervical crown margin (CM); and cement applied to the cervical tooth margin (TM). A comparison microscope (Mitutoyo America Corporation) was used to measure the distances between the internal tangents of two circular marks, one made on the provisional crown and one made apical to the tooth preparation margin, in areas corresponding to buccal, lingual, mesial and distal surfaces. Marginal adaptation was determined before and after cementation, with 0.0001-mm accuracy. Data were analyzed statistically by ANOVA and Tukey's test at 5% significance level. Results: Mean values of marginal opening obtained for each group were: CAO: 145 μm; CA: 67 μm; CM: 46 μm; TM: 34 μm. CA, CM and TM presented significantly lower marginal openings than CAO (p<0.05). Conclusion: complete filling of the crown with provisional cement, including the occlusal surface, provided grater marginal discrepancies when compared to the other methods evaluated.

Highlights

Marginal discrepancies may lead to cement washout and marginal leakage, damaging periodontal and pulp tissues or causing premature loss of the restoration
Within the limits of this in vitro study, it was found that when the provisional cement was applied only to the cervical margins of the prepared tooth, lower marginal discrepancies were obtained (34.3 μm)
Considerably larger marginal discrepancies were observed when the cement was applied to the internal surfaces of the crown, including the occlusal surfaces (144.8 μm), with a high standard deviation, which might be due to the amount of cement applied, as reported elsewhere[5,11]

Summary

Introduction

Marginal discrepancies may lead to cement washout and marginal leakage, damaging periodontal and pulp tissues or causing premature loss of the restoration. An ill-fitting margin may contribute to increase plaque retention and compromise gingival health by causing alterations in gingival microbiota[11], leading to cement washout and loss of retention[2]. This phenomenon has been mainly related to the entrapment of cement between the tooth and the restoration, followed by hydrodynamic intracoronal pressure during cementation, preventing complete seating of the restoration[6]. Several methods have been suggested to improve the seating of crowns after cementation based on the release of hydrodynamic pressure of cementation These techniques rely on venting or internal relief of the restoration[2,4,5,7,10,11]. Few studies have reported the influence of the amount of cement or of the application site on the marginal adaptation of cemented crowns[2,5,11]

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