Biomechanical Phenomena, Partial Edentulism
Conditions
Keywords
titanium base, ti-base, zirconia bridge, intraoral cementation, passive fit, screw-retained restoration, strain gauge, CAD/CAM zirconia
Brief summary
This prospective clinical study compares two cementation techniques for implant-supported zirconia fixed partial dentures on titanium bases (Ti-bases): extraoral cementation performed on the working model and intraoral cementation performed chairside. Thirty clinical cases with two osseointegrated implants requiring a multi-unit zirconia restoration will be recruited at the UIC Dental Clinic. For each case, two restorations with identical design will be produced: one will be cemented extraorally (control) and an identical replica will be cemented intraorally (test). Micro-deformation will be assessed as peri-implant microstrain (µε) using a standardized strain-gauge setup and the same recording protocol for both techniques. The primary analysis compares microstrain between intraoral and extraoral cementation within each case; implant/prosthetic events will be recorded descriptively.
Detailed description
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.
Interventions
PROCEDUREExtraoral cementation on Ti-bases
Extraoral (laboratory) cementation of a three-unit zirconia bridge to Ti-bases on the working model using a standardized protocol, with strain-gauge evaluation performed prior to prosthesis delivery.
PROCEDUREIntraoral cementation on Ti-bases
Intraoral (chairside) cementation of an identical three-unit zirconia bridge to Ti-bases following a standardized protocol. The assembly is removed and sent to the laboratory, where strain-gauge evaluation is performed approximately 1 week later (7 ± 3 days).
Sponsors
Universitat Internacional de Catalunya
Study design
Allocation
NON_RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
NONE
Masking description
Blinding was not feasible. The evaluator knows which condition is being assessed because the extraoral (laboratory) cementation is evaluated first and the intraoral (chairside) cementation is evaluated afterwards; the two conditions are not assessed at the same time. To reduce bias, the same standardized strain-gauge setup and recording protocol are used for both measurements.
Intervention model description
Within-case paired comparison: for each enrolled clinical case, two identical zirconia bridges are fabricated. One is cemented extraorally to Ti-bases (control) and an identical replica is cemented intraorally (test). Microstrain is measured for both conditions using the same protocol, allowing a paired analysis within each case.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
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).
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Peri-implant microstrain (µε) measured by strain gauges | Pre-delivery (laboratory assessment) and ~1 week after intraoral cementation (7 ± 3 days). | Micro-deformation around implant replicas supporting a three-unit zirconia bridge on Ti-bases, recorded with bonded strain gauges and expressed as microstrain (µε). Measurements are obtained for both cementation techniques (extraoral vs intraoral) using the same standardized recording protocol. Measurements for the extraoral (control) restoration are recorded prior to delivery, and measurements for the intraoral (test) restoration are recorded approximately 1 week after chairside cementation once the restoration is received by the laboratory. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Difference in microstrain between techniques (paired within-case) | Pre-delivery (laboratory assessment) and ~1 week after intraoral cementation (7 ± 3 days). | Within each case, the difference in microstrain (µε) between intraoral and extraoral cementation is calculated using paired measurements to assess the magnitude and direction of the effect. Measurements for the extraoral (control) restoration are recorded prior to delivery, and measurements for the intraoral (test) restoration are recorded approximately 1 week after chairside cementation once the restoration is received by the laboratory. |
Countries
Spain
Contacts
CONTACTMARTA VALLES, DDS, PhD
CONTACTPatricia Freire, DDS
PRINCIPAL_INVESTIGATORMARTA VALLES, DDS, PhD
Universitat Internacional de Catalunya
Outcome results
None listed