{'fraction_non_alphanumeric': 0.029088558500323207, 'fraction_numerical': 0.014867485455720749, 'mean_word_length': 4.976833976833976, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Retrospective clinical evaluation of 86 Procera AllCeram anterior single crowns on natural and implant-supported abutments.

BACKGROUND
The Procera AllCeram (Nobel Biocare AB, Göteborg, Sweden, and Procera Sandvik AB, Stockholm, Sweden) technique is one alternative to metal-ceramic restorations. However, few long-term evaluations of its use for single crowns on natural and implant-supported abutments are available.


PURPOSE
The aim of the present study was to assess the clinical performance of Procera AllCeram single crowns when placed in aesthetic sites supported by either natural teeth or implants over a period of 48 months.


MATERIALS AND METHODS
Eighty-six single crowns were fabricated and used in 51 patients. The restorations were examined according to the California Dental Association's quality assessment system.


RESULTS
One crown was lost after 20 months of follow-up. Of the 85 restorations that completed the 48-month follow-up, only one crown (1.2%) showed a veneering porcelain chip. All crowns were ranked as either excellent or acceptable. The success rates of single crowns supported by natural tooth and implant-supported abutments were 100% and 98.3%, respectively; the total crown success rate was 98.8%.


CONCLUSION
Within the limitations of the present study, Procera AllCeram crowns proved to be a reliable therapeutic choice for the restoration of anterior teeth on both natural and implant-supported abutments. The hybrid glass-ionomer cement used in the present study appeared to be a reliable luting agent.