Cost Effectiveness of Various Implant Placement Protocols in the Esthetic Zone

Cost Effectiveness of Various Implant Placement Protocols in the Esthetic Zone - a Non-randomized Controlled Trial

Loss of teeth in the anterior upper jaw significantly affects both well-being and chewing function. Nowadays, dental implants are the treatment of choice for replacing missing teeth with fixed dental prostheses and are often placed in the anterior upper jaw. Depending on various patient-related factors, protocols for the placement of dental implants involve the following time points after tooth extraction: On the same day (immediate implantation) After 1-4 months (early implantation) After more than 4 months (late implantation). The different treatment protocols have been investigated over long periods. The choice of the individually suitable treatment protocol for dental implantation depends on many factors and is of utmost importance in order to achieve the best possible treatment outcomes. Selecting an inappropriate treatment protocol would otherwise result in an increased risk of failure. After decades of research and development in dental implantology, an expert association (International Team for Implantology, ITI) published an evidence-based decision management tool in 2022. This decision management tool assists dentists in choosing the individually suitable implant treatment protocol for single-tooth replacement in the upper jaw. A structured examination of the tooth to be extracted allows to classify the situation and select the most suitable treatment protocol for the individual situation. The treatment protocols differ in terms of time and material requirements, which are associated with different costs. There is limited data about the cost-effectiveness of these treatment protocols. The present study aims to assess how the costs of the three treatment protocols differ in relation to treatment success.

Tooth loss in the visible esthetic zone of the anterior maxilla strongly impairs both patients' psychosocial well-being and masticatory function with a high demand for tooth replacement. Therefore, single tooth replacement by dental implant therapy is a very frequent indication in the esthetic zone, being corroborated with high expectations on esthetic parameters of the treatment outcomes. Depending on local, systemic, surgical, and prosthetic factors, dental implant placement can be carried out utilizing different protocols according to the time after tooth extraction: immediate (same day, fresh extraction socket), early (1-4 months, soft tissue healing), or late (more than 4 months after tooth extraction, bone healing). Insufficient weighting of risk factors may lead to the selection of a too risky implant placement protocol, which may cause implant failures in the esthetic zone. Therefore, the appropriate selection of timepoint and corresponding surgical protocol for implant placement are of outmost importance to achieve satisfying and predictable long-term treatment outcomes in the esthetic zone. To guide clinicians in the choice of the individually appropriate placement protocol for single tooth replacement in the esthetic zone, an evidence-based decision management tool was developed and released by the International Team for Implantology (ITI) in 2022 after decades of research and developments in dental implantology. The flowchart includes radiographic and clinical pre- and intraoperative assessments when extracting a failing tooth, to apply defined inclusion/exclusion criteria to the individual case and define the indicated implant placement protocol aiming at high implant survival and success rates. Besides the timepoint of implant placement, the implant placement protocols involve differing amount of surgeries (immediate: 1-2, early: 3, late: 3-4), techniques for tissue augmentation including varying amount of biomaterials (immediate: socket grafting (SG), early: guided bone regeneration (GBR), late: SG and GBR) and estimated overall clinical visits (immediate: minimum 4, early: minimum 5, late: minimum 6). All these factors contribute to the operating costs of a private practice/dental clinic in implant dentistry, with the majority of costs being composed of material costs and the procedural time involved. To date, there is a lack of data about the cost effectiveness of dental implant placement using varying implant placement protocols. Therefore, this study is designed to primarily evaluate the surgical costs in relation to the implant survival rates of implant placement procedures using various placement protocols as indicated by an evidence-based decision management tool. The secondary outcomes include the assessment of placement protocol frequency, biological/mechanical/technical complication rates and the long-term stability of regenerated tissues.

Esthetic Zone, Single Tooth Lost, Accuracy of Dental Implants, Dimensional Changes, Patient Reported Outcome Measures, Implant Survival and Success, Cost-effectiveness, Cost-Benefit Analysis, Complications, Frequency of Treatment Protocol, Single Tooth Dental Implant

Immediate implant placement The extraction of the failing tooth will be carried out. Subsequently, immediate implant placement and bone grafting of the intra-alveolar space by the means of a well-documented xenogeneic bone substitute will be carried out, will be conducted all in one single surgical intervention. After a healing period of at least 8 weeks, implant reopening takes place (conventional loading protocol).

Early implant placement The extraction of the failing tooth will be carried out. Within a healing period of 4-16 weeks, the extraction socket will be completely covered by soft tissues. Implant placement and bone grafting by the means of guided bone regeneration using locally harvested autogenous bone and a well-documented xenogeneic bone substitute will be carried out. After a healing period of at least 8 weeks, implant reopening takes place (conventional loading protocol).

Late implant placement The extraction of the failing tooth and a socket grafting procedure using a well-documented xenogeneic bone substitute will be carried out. Within a healing period of at least 16 weeks, the extraction socket will be completely covered by soft tissues and complete bone healing is anticipated. Implant placement and bone grafting by the means of guided bone regeneration using locally harvested autogenous bone and a well-documented xenogeneic bone substitute will be carried out. After a healing period of at least 8 weeks, implant reopening takes place (conventional loading protocol).

The extraction of the failing tooth will be carried out. Subsequently, immediate implant placement and bone grafting of the intra-alveolar space by the means of a well-documented xenogeneic bone substitute will be carried out, will be conducted all in one single surgical intervention. After a healing period of at least 8 weeks, implant reopening takes place (conventional loading protocol).

The extraction of the failing tooth will be carried out. Within a healing period of 4-16 weeks, the extraction socket will be completely covered by soft tissues. Implant placement and bone grafting by the means of guided bone regeneration using locally harvested autogenous bone and a well-documented xenogeneic bone substitute will be carried out. After a healing period of at least 8 weeks, implant reopening takes place (conventional loading protocol).

The extraction of the failing tooth and a socket grafting procedure using a well-documented xenogeneic bone substitute will be carried out. Within a healing period of at least 16 weeks, the extraction socket will be completely covered by soft tissues and complete bone healing is anticipated. Implant placement and bone grafting by the means of guided bone regeneration using locally harvested autogenous bone and a well-documented xenogeneic bone substitute will be carried out. After a healing period of at least 8 weeks, implant reopening takes place (conventional loading protocol).

Absence of persisting subjective discomfort such as pain, foreign body perception and or dysaesthesia (e. g. painful sensation), absence of a recurrent peri-implant infection with suppuration (where an infection is termed recurrent if observed at two or more follow-up visits after the treatment with systemic antibiotics), absence of implant mobility on manual palpation, absence of any continuous peri-implant radiolucency

The frequency of application of the various types of implant placement (immediate, early, late), when applying the inclusion-criteria of a decision management tool

Biological/technical/mechanical complication rates as defined by (Salvi et al., 2009; Schwarz et al., 2018)

Patient-centered outcomes: placement protocol-related satisfaction (visual analogue scale (VAS)-based questionnaire)

Accuracy of the final implant position compared of computer-assisted implant placements compared to the virtually pre-operatively planned implant position by superimposition of intraoral scans

Mesial and distal implant bone level changes using standardized and digitized peri-apical radiographs

Inclusion Criteria: Age ≥ 20 years Willingness and ability to sign informed consent (Appendix Informed Consent Form) and to participate in the study Plaque index according to Silness and Loe of < 35% Presence of a single tooth (FDI positions 15 - 25) that has to be extracted Sufficient vertical interocclusal space for the placement of an implant crown (FDI regions 13-23: 3 mm, FDI regions 15, 14, 24, 25: 6 mm) Ridge height sufficient for the placement of a ≥ 8 mm-long implant Sufficient ridge width for the placement of a 2.9 mm diameter implant (min. 5 mm) Exclusion Criteria: Any physical or mental disorder that would interfere with the ability to perform adequate oral hygiene or the capability of providing written informed consent and compliance to the protocol Any disorder that would interfere with wound healing or represent a contraindication for implant surgery such as, but not limited to, uncontrolled diabetes or conditions resulting in or requiring immunosuppression, radiation, chemotherapy, frequent use of antibiotics or antiresorptive medication such as bisphosphonates Pregnancy (pregnancy tests will be applied; see chapter 6.5) Intention to become pregnant between inclusion and implant loading Heavy smoking habit with ≥ 10 cig/d Allergy to titanium Severe bruxism or clenching habits, present oro-facial pain Insufficient ridge width/height for the study implant

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