Comparative assessment of the gingival status and alveolar bone level between flap and flapless surgical technique with immediate placement of healing abutment over dental implant a randomized controlled clinical trial

Dental implant therapy has been demonstrated to be a highly successful and predictable treatment modality for replacement of missing teeth.1 However, achieving implant aesthetics remains a challenge with respect to re-creating a natural appearing gingival margin and papilla. With the rapid advancement of dental implant therapeutics, the current trend is more geared toward enhancing aesthetics and patient comfort and satisfaction. Papilla preservation and predictable soft tissue margins around dental implants are major aesthetic concerns, particularly for patients who have a high smile line. There has been a report of postsurgical tissue loss from flap reflection2, implying that flap surgery for implant placement may negatively influence implant aesthetic outcomes, especially in the anterior maxilla. One technique to overcome this concern is flapless implant placement with immediate healing abutment.

This technique involves removing a small amount of tissue over the crest of the edentulous ridge, just sufficient to expose the underlying bone to facilitate implant placement. As a consequence, no sutures are required, and no soft tissue flap is reflected, potentially reducing postoperative discomfort and swelling3. This is in contrast to the traditional flap approach with immediate healing abutment, in which an incision is made through the gingiva along the crest of the ridge, and the gingival tissue is reflected away from the underlying bone to allow access for implant placement. The traditional technique requires suturing; potentially involves more postoperative bleeding, discomfort, and swelling; and may result in a compromised aesthetic result due to the potential bone loss and recession associated with raising a flap4.

A study in beagle dogs compared buccal bone plate resorption between flapless and flap approaches to implant placement5. At 3 months, the flapless approach resulted in 0.67 mm less buccal bone resorption than the flap approach. This study and several other clinical trials in humans provide evidence that a flapless approach may provide some additional advantages over traditional flap implant placement protocols and could have a use in regular clinical practice 5-10. One study directly comparing the two surgical approaches evaluated bone density surrounding the implants over a period of 18 months and found no difference among the study groups11. Another study evaluating the flap versus flapless approach found no difference in either survival rates or bone density (as measured using radiograph) among the groups10. Fewer studies are available to provide information on aesthetic outcomes and other measures of implant success versus merely survival. In 2006, one group used a flapless surgical approach to compare early versus delayed loading of implants8. The results of that study indicated that a flapless approach results in an aesthetic soft tissue profile that is stable for up to 6 months.

Since the flapless approach is a relatively new treatment approach, data regarding healing patterns of peri-implant tissues, implant survival/success rates, and Aesthetic outcomes are not sufficient in the literature1. Although some studies have compared outcomes between the flapless and traditional flap approach, Aesthetic outcomes have not been a major focus. Hence, the primary objective of this randomized controlled study is to compare clinical outcomes of flapless implant surgery with healing abutment with those of traditional flap implant placement with immediate healing abutment.