The Influence of Vertical Implant Position With Immediate Provisionalization on the Marginal Bone Loss.

Study Overview
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Brief Summary
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Multiple clinical studies have established high survival rates and tremendous predictability of dental implant treatment. However, a pleasant esthetic outcome is the patient's primary expectation regarding implants in the esthetic zone and several esthetic factors have been evaluated to contribute to an esthetic appearance. Among these, the midfacial soft tissue level is considered to be one of the most important factors; Cosyn and co-workers reported that among factors including soft tissue phenotype, the midfacial recession was associated with the position of the implant . Therefore, subcrestal implant placement has been advocated as it has been associated with the reduction of crestal bone loss in cases with decreased soft tissue thickness. If the vertical soft tissues on the crest of the alveolar ridge are 2 mm or less at the time of implant placement, implants will undergo unavoidable bone resorption by establishing sufficient biologic protection. Another option was proposed by Linkevicius et al, who introduced the subcrestal implant placement as a method to accommodate the problem of thin soft tissues. Research question: Does the placement of delayed implants with different vertical depth affect the marginal bone loss with immediate provisionalization?

Detailed Description
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Preservation of crestal bone is crucial and must be prioritized from the onset of implant placement. Adequate amount of peri-implant bone contributes to esthetic success and implant stability. Crestal bone contributes to both esthetics and function. Resorption of crestal bone is seen as loss of interproximal papillary support and gingival recession, which gives way to peri-implantitis and compromises esthetics. With respect to the depth of insertion, implants can be placed at various levels in the bone, in which affects the peri-implant tissues with the surrounding marginal bone. Therefore, Placement of an implant in a deeper position with re¬spect to the bone crest (subcrestal placement) has been suggested as a method that could contribute to main¬tain the periimplant soft and hard tissues in comparison with crestal placement, though this affirmation is sub¬ject to controversy. Rationale for conducting the research: Limiting the extent of peri-implant bone loss has been recognized for decades to be an important aspect of long-term implant success, and stable peri-implant bone conditions play an important role in maintaining esthetics. the opinion expressed widely in the scientific literature has been that subcrestal implant placement leads to increased crestal bone resorption. However, clinical studies addressing the implant placement depth in relation to crestal bone have been rare. Data on subcrestal versus crestal placement have mostly come from animal studies. Even fewer data are available regarding the effects of crestal versus subcrestal positioning of platform-switched implants. In a prospective research, Nagarajan et al. implanted equicrestal and subcrestal implants to examine the crestal bone levels prior to loading. The crestal bone levels of the implants placed equicrestally (1.31 mm 1.04 mm and 0.68 mm 1.08 mm on mesial and distal surfaces, respectively) were higher than those of implants placed subcrestally (0.49 mm 0.49 mm and 0.025 mm 6.06 mm on mesial and distal surfaces, respectively), with a P value of crestal bone level for both groups being 0.12 and 0. They came to the conclusion that there was no difference in the amount of crestal bone loss prior to prosthetic loading between implants placed at subcrestal and equicrestal levels. In this study eqi-crestal implant will be used as a comparator but with immediate loading.

Official Title
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The Influence of Vertical Implant Position With Immediate Provisionalization on the Marginal Bone Loss: A Randomized Controlled Clinical Trial

Conditions
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Dental Implant Failed, Implant Site Reaction

Intervention / Treatment
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* Procedure: Sub-crestal implant
* Procedure: Equi-crestal implant


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ● Patients with single missing upper anterior or premolar teeth Patients with minimum buccolingual width of 6 mm and mesiodistal width of 6mm Patients with healthy systemic conditions. Patients older than 18 years. Good oral hygiene. Accepts one year follow-up period (cooperative patients). The patient provides informed consent. Adequate Inter-arch space for implant placement. Favorable occlusion (no traumatic occlusion). Absence of allergy to the prescribed medications. Exclusion Criteria: ● Patients with inadequate bone volume and/ or quality Patients with local root remnants Patients with inadequate wound healing Patients with signs of acute infection related to the area of interest. Patients with habits that may jeopardize the implant longevity and affect the results of the study such as parafunctional habits (Lobbezoo et al., 2006). Heavy smokers patients (more than 10 cigarettes per day) (Lambert, Morris and Ochi, 2000). Metabolic diseases such as diabetes or hyperthyroidism as well as systemic medications such as chemotherapy or bisphosphonates Pregnant or nursing women. Uncooperative patients.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Sub-crestal group<br>Patients receiving delayed implant placed 2mm sub-crestal level with immediate provisionalization | Procedure: Sub-crestal implant<br>* Patients receiving delayed implant placed 2mm sub-crestal level with immediate provisionalization<br>|
| Experimental: Equi-crestal grouo<br>Patients receiving delayed implant placed equi-crestal level with immediate provisionalization | Procedure: Equi-crestal implant<br>* Patients receiving delayed implant placed equi-crestal level with immediate provisionalization<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Marginal bone loss | Crestal bone loss | 1 year follow up | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mid facial recession | Corono-apical distance between the peri-implant soft tissue margin and the cemento-enamel junction (CEJ) of the homologous contralateral tooth. Midfacial recession will be measured at 6, and 12 months. | 1 year follow up | 
| The pink esthetic score | The pink esthetic score will be calculated on the parameters defined by. Clinical photographs will be taken to evaluate peri-implant soft tissue through evaluating seven variables compared to a natural reference tooth including: mesial papilla, distal papilla, soft-tissue level, soft-tissue contour, alveolar process deficiency, soft-tissue color and texture. Using a 0-1-2 scoring system, 0 being the lowest, 2 being the highest value. The maximum achievable PES is 14. | 1 year follow up | 
| Gingival Thickness | Gingival thickness will be measured using an anesthetic needle with a rubber stopper, trans-gingivally piercing tissues horizontally perpendicular to the long axis of the tooth/implant until it contacts bone, at 3 different points; three readings mid-buccally at three different levels; 2mm, 4mm and 6mm apical to the gingival margin. The length of the part of the instrument that penetrates into the soft tissue is measured in mm using a digital caliper (Wiesner et al., 2010). | 1 year follow up | 
| Implant Survival | A binary outcome, the definition of implant success was based on the clinical and radiographic criteria;1) absence of clinically detectable implant mobility; 2) absence of pain or any subjective sensation; 3) absence of recurrent peri-implant infection; and 4) absence of persistent radiolucency around the implant after 12 months of loading | 1 year follow up | 
| Post-operative patient satisfaction | A 12-items questionnaire are self-reported by the patients after 12 months post-operative; 6 questions with with visual analoge scale from 1 to 10 with poorest score is not very satisfied equal 0 and optimum score is satisfied which equals 10. The another 6 questions is yes or no questions This questions measure patient's acceptability and esthetics satisfaction | 1 year follow up | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Delayed Implant, Immediate loading, Temporization, provisionalization