Aim: The aim of the present study to clinically evaluation of monolithic zirconia crown.
Methods: This prospective study conducted in the, Department of Dentistry, Anugrah Narayan
Magadh Medical College and Hospital, Gaya, Bihar, India for 18 months. This study based on
record evaluation and clinical examination of patients treated with tooth-supported monolithic
zirconia single crowns was performed. The inclusion criteria were as follows: age >18 years,
need for crown treatment in the permanent teeth, pre-prosthetic treatment completion, low
caries activity, good oral hygiene, regular dental check-ups.
Results: Thirteen patients (mean age, 53.1±12.0 years; gender, four men and nine women)
participated in this study, and 40 monolithic zirconia crowns were provided in total. The mean
follow-up time was 2.0 ± 1.0 years (range 0.14.3 years). All patients continuously responded
to a request to attend a recall every 3 to 6 months. Only one crown was placed with resin
modified glass ionomer cement; the rest of the crowns were placed with resin cement. During
this period, clinical complications were found in four crowns, and the details were as follows:
1) fracture of the crown (two crowns), 2) abrasion of the crown (one crown), and 3) fracture of
the antagonist tooth (one crown). Of the four cases of failure, three (cases 1, 3, and 4) were
treated by the same clinician and the four crowns fabricated by different dental technicians.
The crown fractures occurred 0.8 and 1.5 years after placement and propagated medio-distally
and buccal lingually from the central occlusion region, respectively. The fractured crowns had
a minimum thickness of approximately 0.6 mm, and the antagonist teeth had been restored with
a metal inlay and monolithic zirconia crown. In the case of crown abrasions, loss of retention
of the crown was caused by the wear of the crown placed in the lower left of the first molar. Its
antagonist tooth was a natural tooth. In case 4, chipping of the antagonist tooth occurred 0.1
year after crown placement. In this case, a metal partial- coverage crown was placed on the
antagonist teeth. Three of these were placed on the rearmost tooth. The estimated Kaplan-Meier
3.5-year success and survival rates of the 40 monolithic zirconia crowns were 90.5% (95%
confidence interval [CI]: 73.197.1) and 92.8% (95% CI: 74.198.3), respectively.
Conclusion: Considering the limitation of the study period, our results suggest that the molar
application of monolithic zirconia crowns requires detailed attention to interocclusal clearance
and whether the antagonist tooth has been partially restored
Key words: monolithic zirconia, crown, abrasions