A comparison of the depths produced using three different tooth preparation techniques

Area of Science:

• Dental Materials Science
• Restorative Dentistry
• Prosthodontics

Background:

• Inadequate tooth preparation for metal ceramic crowns compromises restoration longevity and affects supporting tissues.
• Consistent and accurate preparation is essential for successful definitive restorations.

Purpose of the Study:

• To evaluate the impact of three distinct tooth preparation techniques on operator consistency.
• To determine the effectiveness of freehand, silicone index, and depth gauge bur methods for metal ceramic crown preparation.

Main Methods:

• Thirty typodont maxillary central incisors were prepared by one operator using three techniques: freehand (control), silicone index, and depth gauge bur.
• Preparation depth was measured using a silicone index, optical microscopy, and image analysis software at five specific points.
• Statistical analysis included one-way ANOVA and Scheffe's post hoc test (P<.05).

Main Results:

• Palatal preparation depth differed significantly between groups (P=.01).
• Incisal reduction was significantly less with the depth gauge bur (2.13 mm) and silicone index (2.74 mm) compared to freehand (3.00 mm) (P=.00).
• Labial preparation depth showed no significant difference (P=.06).

Conclusions:

• Freehand preparation without depth control can lead to insufficient labial reduction and excessive incisal reduction.
• Utilizing a depth gauge bur or silicone index enhances preparation consistency for metal ceramic crowns.
• A depth gauge bur appears most effective in controlling incisal reduction.