Intraoral vs Extraoral Cementation of Zirconia Bridges on Ti-Bases: Microstrain Evaluation

This study will evaluate whether the cementation approach of zirconia restorations onto Ti-bases influences peri-implant strain. Two clinical workflows are compared: (1) extraoral cementation of the zirconia restoration to Ti-bases on the working model prior to delivery, and (2) intraoral chairside cementation of an equivalent restoration to Ti-bases using the same intended clinical seating conditions.

For each enrolled case, two restorations with the same design will be fabricated so that both cementation approaches can be assessed within the same case. After cementation, restorations will be evaluated using a standardized strain-gauge measurement setup on a model reproducing the clinical implant relationship, applying the same torque and recording procedure for both techniques.

All clinical procedures will be performed at the UIC Dental Clinic, and strain-gauge recordings will be performed at the collaborating center (Universidad Europea Miguel de Cervantes, UEMC) following a consistent protocol. Data will be handled using study codes, and only study-coded technical files will be shared with the collaborating center.

Inclusion criteria

• Adults (≥18 years old) in good general health.
• Presence of an edentulous space requiring rehabilitation with a three-unit implant-supported fixed bridge.
• Presence of two already osseointegrated Essential Cone implants (Klockner) indicated for a three-unit implant-supported restoration in the edentulous area.
• Ability and willingness to participate and attend study visits and follow-up.
• Signed informed consent.

Exclusion criteria

• ASA III or ASA IV.
• Current or previous treatment with bisphosphonates.
• Smoking >10 cigarettes/day.
• Extraction in the study area <3 months before implant placement with incomplete healing.
• Guided bone regeneration in the study area with <6 months of healing time.
• Signs of active periodontal disease (e.g., poor plaque control and/or bleeding on probing above acceptable levels).