A comparative assessment of the submergence levels on the soft tissue emergence profile of dental implants placed in aesthetic zone – An in-vivo study

Background

Successful implant treatment demands the best gingival esthetics success along with stability and function of implant. Esthetics is important when implants are placed in the anterior maxilla. The goal of a dental implant is to restore missing teeth by placing implants that are anatomically correct and esthetically pleasing in functional positions. There are two approaches for the implant placement in relation to the bone- submerged and nonsubmerged

Aim/Hypothesis

To assess the emergence profile around dental implants when placed at crestal level. To assess the emergence profile around dental implants when placed at 1 mm sub-crestal level. To compare the difference in emergence profile observed when implants are placed at crest and 1 mm sub-crestal level.

Material and Methods

Pre-surgical evaluation comprised of radiographic investigations, systemic evaluation and study models, routine blood investigation. Radiographic guides and surgical stent was prepared for all the cases. All the implants were of OSSTEM TSII placed following Branemark's 2 stage surgical protocol. The diameter and length of the implant was selected as per the available bone. For control group, implants were placed at crest level and for test group implants were placed 1 mm subcrestally. 3–4 months later, stage 2 surgery was carried out. Cover screw was removed and gingival former with the height of 7 mm was used for both control and test group. After a period of 7 days gingival cuff was formed around the gingival former. Once the gingival cuff formation was found satisfactory, emergence profile was evaluated using depth gauge at four distinct points (mesial, distal, midfacial, midpalatal) when the was gauge placed at crest module of the implant.

Results

Assessment of emergence profile at crest level implants (Group A)- The mucosal height values were approximately 3.20 mm distally, 3 mm mesially, 2.73 mm midpalatally and 2.07 mm mid-facially when implants were placed at crest level. Assessment of emergence profile at sub-crustal level implants (Group B)- Mean of mucosal height values when implants were placed sub-crestally were 4.13 mm distally, 3.87 mm mesially, 3.40 mm midpalatally and 2.73 mm mid-facially. Comparison of emergence profile at crest and sub-crustal level implants (Group A and Group B) Unpaired T test was applied keeping the confidence levels at 95% (P < 0.05). The results of this study show that the formation of emergence profile was significantly better with submerged implants than crest level implants.

Conclusion and Clinical Implications

The formation of emergence profile around dental implants when placed at 1 mm sub-crestal level was better than when implants were placed at crest level. Therefore, subcrestal implant positioning could be suggested as a way to maintain and reposition peri-implant soft and hard tissue. formation of the gingival cuff which is understood as the biologic width. A well formed biologic width allows for the obvious benefits of esthetics, microbial protection and also reduced crestal bone loss.