Oval Abutment Versus a Circular Abutment in Dental Implants in the Anterior Maxillae

Study Overview
=================
Brief Summary
-----------------
Objetive: The main objective of this clinical trial is to assess whether the oval section abutment of a 2.9mm implant achieves a greater covering of the tooth-implant papilla compared to a circular section abutment in 3.3mm implants in upper lateral incisors and lower central / lateral incisors. Material and methods: fourty patients received unitary implants of 3.3mm or 2.9 mm diameter to replace the absence of upper lateral incisor or lower central/lateral incisor with an edentulous space of at least 6.4mm (mesio-distally). Esthetic and clinical parameters were evaluated 12 months after installation of the prosthesis. Condition or disease: dental implants Intervention/treatment: 3.3 or 2.9 mm diameter dental implants Phase: Not Applicable

Detailed Description
-----------------
The study was a double-blind controlled clinical trial (RCT) comparing the oval section abutment of a 2.9mm (test group) to a circular section abutment in 3.3mm (control group) implants for the replacement of a single tooth. The choice of the diameter to be used as recommended by the manufacter, was determined by the mesiodistal width between the two adjacent natural teeth, in order to maintain at least 1.5mm between the implant and the adjacent tooth. When said the distance was between 5.9 and 6.3 mm, a 2.9 mm implant was placed, while if the width ranged between 6.4 and 7.1 mm, a 3.3 mm implant was placed. Both implant designs are made of a titanium and zirconium alloy (Roxolid®) with a SLActive® surface (Institut Straumann AG, Basel, Switzerland). The main objective was the papillary index (PI) (Jemt, 1997). It consists in four scores: 0 = absence of interdental papilla; 1 = filling of the interdental space less than 50% of the soft tissues; 2 = filling of the interdental space greater than 50% of the soft tissues; 3 = total filling of the interdental space with good aesthetic harmony; 4 = Hyperplasic interdental papilla formation with irregular soft tissue. Both mesial and distal papilla will be recorded. The secondary objectives are (a) to observe the stability of the soft and hard tissues after one year in function, (b) to assess the success and survival rate of the implants, (c) to assess the stability of the implants and their evolution and (d) to analyze the degree of patient satisfaction with the aesthetic result.

Official Title
-----------------
A Randomized Controlled Clinical Trial Comparing the Placement of an Oval Abutment in 2.9 mm Implants Versus a Circular Abutment in Implants of 3.3 mm to 12 Months of Evolution

Conditions
-----------------
Dental Implants

Intervention / Treatment
-----------------
* Procedure: Oval section abutment of 2.9 mm
* Procedure: Circular section abutment of 3.3 mm


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients >18 years of age Absence of upper lateral incisors or lower central / lateral incisors with an edentulous space of at least 6.4mm (mesio-distally). The teeth adjacent to the edentulous space must be natural. Patients who are in periodontal health. Signing of informed consent before entering the study. Exclusion Criteria: Patients with any systemic condition or disease that may interfere with oral surgery. History of radiotherapy. Patients smoking more than 20 cigarettes per day. Pregnant or breastfeeding patients.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: The study was a double-blind controlled clinical trial (RCT) comparing the oval section abutment of a 2.9mm (test group) to a circular section abutment in 3.3mm (control group) implants for the replacement of a single tooth. The choice of the diameter to be used as recommended by the manufacter, was determined by the mesiodistal width between the two adjacent natural teeth, in order to maintain at least 1.5mm between the implant and the adjacent tooth. When said the distance was between 5.9 and 6.3 mm, a 2.9 mm implant was placed, while if the width ranged between 6.4 and 7.1 mm, a 3.3 mm implant was placed. Both implant designs are made of a titanium and zirconium alloy (Roxolid®) with a SLActive® surface (Institut Straumann AG, Basel, Switzerland).
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: oval section abutment of a 2.9mm<br>The choice of the diameter to be used as recommended by the manufacter, was determined by the mesiodistal width between the two adjacent natural teeth, in order to maintain at least 1.5mm between the implant and the adjacent tooth. When said the distance was between 5.9 and 6.3 mm, a 2.9 mm implant was placed. Implant designs are made of a titanium and zirconium alloy (Roxolid®) with a SLActive® surface (Institut Straumann AG, Basel, Switzerland). | Procedure: Circular section abutment of 3.3 mm<br>* The choice of the diameter to be used as recommended by the manufacter, was determined by the mesiodistal width between the two adjacent natural teeth, in order to maintain at least 1.5mm between the implant and the adjacent tooth. When said the distance was between 6.4 and 7.1 mm, a 3.3 mm implant was placed. Implant designs are made of a titanium and zirconium alloy (Roxolid®) with a SLActive® surface (Institut Straumann AG, Basel, Switzerland).<br>* Other names: Prosthetic treatment over a circular section abutment of 3.3.mm;|
| Placebo Comparator: circular section abutment in 3.3mm<br>The choice of the diameter to be used as recommended by the manufacter, was determined by the mesiodistal width between the two adjacent natural teeth, in order to maintain at least 1.5mm between the implant and the adjacent tooth. When said the distance was between 6.4 and 7.1 mm, a 3.3 mm implant was placed. Both implant designs are made of a titanium and zirconium alloy (Roxolid®) with a SLActive® surface (Institut Straumann AG, Basel, Switzerland). | Procedure: Oval section abutment of 2.9 mm<br>* The choice of the diameter to be used as recommended by the manufacter, was determined by the mesiodistal width between the two adjacent natural teeth, in order to maintain at least 1.5mm between the implant and the adjacent tooth. When said the distance was between 5.9 and 6.3 mm, a 2.9 mm implant was placed. Implant designs are made of a titanium and zirconium alloy (Roxolid®) with a SLActive® surface (Institut Straumann AG, Basel, Switzerland).<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The main objective was the papillary index (PI) (Jemt, 1997) | It consists in four scores: 0 = absence of interdental papilla; 1 = filling of the interdental space less than 50% of the soft tissues; 2 = filling of the interdental space greater than 50% of the soft tissues; 3 = total filling of the interdental space with good aesthetic harmony; 4 = Hyperplasic interdental papilla formation with irregular soft tissue. Both mesial and distal papilla will be recorded. | 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To observe the stability of the soft and hard tissues after one year in function: probing depth | Probing depth (PD), defined as the distance (mm) between the most apical point of the gingival sulcus or periodontal pocket and the free gingival margin. It will be taken at six points per tooth and in four points by implant. | 12 months | 
| To observe the stability of the soft and hard tissues after one year in function:bleeding on probing | Bleeding on probing (BP) (Ainamo and Bay 1975), presence of bleeding in six points per tooth (3 in vestibular and 3 in lingual or palatal). | 12 months | 
| To observe the stability of the soft and hard tissues after one year in function: suppuration on probing | Suppuration on probing, presence of pus within 15 seconds after probing. | 12 months | 
| To observe the stability of the soft and hard tissues after one year in function: Modified plaque index (MPI) | Modified plaque index (MPI) (Mombelli et al 1987): 0 = no plaque detected; 1 = detection of plaque when a periodontal probe passes over the surface of the implant; 2 = the plaque is visible to the naked eye; 3 = abundant plate. | 12 months | 
| Assessment of survival rate of the implants | The survival rate of the implants will be recorded taking into consideration Albrektsson et al.´s criteria. (Albrektson et al 1986) | 12 months | 
| Assessment of the success of the implants | The implant will be considered successful when: (a) non-detectable clinical mobility (manual test); (b) absence of radiolucency around the surface of the implant; (c) absence of persistent pain; (d) absence of recurrent peri-implant infection. (Buser et al. 1990) | 12 months | 
| Analyze the degree of patient satisfaction with the aesthetic result. | Visual analog scale (VAS): the general patient satisfaction will be evaluated. The specific satisfaction with respect to 5 parameters will also be recorded - aesthetics, mastication, phonation, comfort and self-esteem - using 10 cm visual analog scales calibrated with the terms nothing satisfied and totally satisfied at the left and right ends respectively. | 12 months |