17 January 2022

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Long-term behavior of PICN inlay and overlay CAD/CAM

Simona Chirico

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Inlay and overlay are a good and right choice in case of large carious and restorative defects. The introduction of CAD/CAM system gives the possibilities to provide patients aesthetic, function and long-lasting reliable restorations in one single appointment.
Today we have several studies that give us results on the long term success of lithium disilicate and feldspathic ceramic. But in this last years another CAD/CAM material is used for partial indirect restorations: PICN (polymer infiltrated ceramic network).

How does it work?
The study conducted by Spitznagel et al. tried to answer to this question. They evaluated the long-term behavior of this material in their prospective 5-year study.  

MATERIAL AND METHODS
45 inlays and 58 overlay were prepared with VITA Enamic (PICN), using a CAD/CAM system (inEoS blue/ CEREC inLab MCXL) and adhesively bonded (Variolink II). After te luting procedures, the restorations were evaluated at baseline and after 6, 12, 24, and 36 months, according to modified United States Public Health Service (USPHS) criteria. Absolute failures were demonstrated by Kaplan-Meier survival rate and relative failures by Kaplan-Meier success rate. A logistic regression model was adjusted for modified USPHS criteria to investigate time and restoration effects (p < 0.05).

RESULTS
The survival rate were 97.4% for inlays and 95.6% for overlay, after 3 years. Three restorations had to be replaced due to fractures. Secondary caries and debonding were not observed. The 3-year Kaplan- Meier success rate was 84.8% for inlays and 82.4% for overlay. The decrease in marginal adaption (p = 0.0005), increase in marginal discoloration (p < 0.0001), and surface roughness (p = 0.0005) over time were significant. Color match and anatomic form were excellent. 

CONCLUSIONS  
PICN restorations are a suitable treatment option for the rehabilitation of posterior teeth with inlay and overlay. Even if they showed a favorable clinical performance, more clinical long-term data have to be waited.

(Photocredit: Dr. Simona Chirico)

For additional informations: Polymer-infiltrated ceramic CAD/CAM inlays and partial coverage restorations: 3-year results of a prospective clinical study over 5 years