Objectives: The aim of this in vitro study was to compare the tooth structure removal required for currently available ceramic crown materials.
Material and methods: Ninety typodont teeth (60 incisors, 30 molars) were assigned to nine study groups. The teeth were digitized, weighed with a high-precision balance, and fixed in carriers in identical alignment. Full-crown restorations were prepared according to material-specific guidelines for monolithic zirconia (MZ), polymer-infiltrated ceramics (PIC), buccally veneered zirconia (BVZ), feldspathic ceramics (FC), fully veneered zirconia (FVZ), and lithium disilicate (LD). Tooth structure removal was assessed by weighing the teeth before and after preparation. Coronal volume loss was analyzed statistically by use of one-way ANOVA and post-hoc Tukey HSD tests with α = 0.05.
Results: Mean tooth structure removal for incisors was 42% (SD 2%) for MZ, 46% (SD 1%) for PIC, 50% (SD 2%) for BVZ, 57% (SD 1%) for FC, 57% (SD 2%) for FVZ, and 59% (SD 2%) for LD. Mean tooth structure removal for molars was 21% (SD 2%) for MZ, 31% (SD 1%) for PIC, and 35% (SD 1%) for LD. Inter-group differences were statistically significant, except for between FC and FVZ.
Conclusions: Preparation of full ceramic crowns for restoration-free teeth is an invasive procedure. Selecting the ceramic material can, however, reduce loss of tooth structure substantially.
Clinical relevance: Monolithic zirconia is the least invasive material for the preparation of incisor and molar ceramic single crowns. Prescribing buccally veneered instead of fully veneered zirconia reduces preparation invasiveness significantly.
Keywords: Ceramic crowns; Minimally invasive procedures; Preparation design; Tooth substance removal.