Marginal Fit of Metal‐Ceramic Copings: Effect of Luting Cements and Tooth Preparation Design

Abstract

Lower convergence angle combined with shoulder and a low-consistency luting cement is preferable to cement metal copings.

Effect of Luting Cement and Convergence Angle of the Preparation on the Internal Fit of Zirconia Restorations

“…The internal fit of fixed restorations has been the focus of several studies [23][24][25]; however, investigations of the combined influence of different luting agents with various total occlusal convergence angles are still limited regarding this particular factor, whose results have reported mainly on retention, fracture resistance, and marginal fit [9,10,12,[26][27][28][29]. Water-based luting agents such as ZPC and GIC seem to contribute to an improved fit when compared to RC [9,10]. This can be explained by the influence of viscosity on film thickness when sitting the restoration over the preparation [9,10,12].…”

“…An inadequate internal fit can contribute to microleakage, thus predisposing the abutment tooth to caries, sensitivity, and loss of vitality or even fracture [5,6]. Moreover, the poorer the adaptation between the intaglio surface of the restoration and the tooth preparation, the lower the retention [7,8]; increasing the likelihood of restoration instability and decementation, particularly when the luting agent presents a higher solubility index [9,10].…”

“…From a clinical standpoint, several critical factors are dependent upon the clinician's knowledge and execution capabilities related with tooth preparation design (total preparation occlusal convergence angle, finish line design, occlusal reduction, and surface roughness), impression material selection, and technique, all capable of impacting upon the accuracy of the working cast and, therefore, affecting the resulting restorations. From the dental laboratory perspective, apart from a knowledgeable and careful material selection and execution, adjusting the thickness of cement spacing to meet the future requirements of the luting agent and cementation technique will ultimately be determinant to improve the clinical fit of the restoration after cementation [4,5,[9][10][11].…”

“…Therefore, understanding the influence of internal adaptation in the success of fixed prosthodontics is a clinically revenant factor to predict the outcome and longevity of a given restoration. Several studies have shown that factors such as preparation and restoration design, restorative material, manufacturing system, and luting agent, can influence the restoration/abutment fit [3,[9][10][11]19,20]. This multitude of influencing factors may help explain the disparity of results reported among studies regarding restoration fit [6,21,22].…”

Evaluation of the Marginal and Internal Fit of Implant‐Supported Metal Copings Fabricated with 3 Different Techniques: An In Vitro Study

“…de Almeida et al evaluated the effect of cement and tooth preparation on the marginal fit of metal‐ceramic copings. They stated that high consistency cement type and a convergence angle of 20° would increase the marginal fit of copings.…”