Management of edentulous spaces has been revolutionized by dental implants. Dental implant therapy has replaced most of the conventional methods of treating edentulous patients and has become a highly predictable treatment modality. Albrektsson et al. [4] in 1986 proposed certain criteria to assess success of implants. According to these criteria, bone loss of less than 0.2 mm annually following the implant’s first year of function is stated as being essential for long-term success [4]. Since then, the crestal bone area has been considered as a significant indicator of implant health. With the rapid advancement of dental implant therapeutics, the current trend is now geared toward enhancing esthetics and patient comfort. Establishing intact papillae and gingival contour around implants is of utmost importance, especially in patients who display soft tissue during function, such as speaking and smiling.

Branemark established the use of extensive surgical flaps to visualize the surgical field during implant surgery [5]. In the early 1970s, studies demonstrated a correlation between flap elevation and gingival recession, as well as bone resorption around natural teeth [6]. Furthermore, there has been a report of postsurgical tissue loss from flap elevation, implying that the use of flap surgery for implant placement may negatively influence implant esthetic outcomes, especially in the anterior maxilla [7]. Over the past 30 years, flap designs for implant surgery have been modified, and more recently, the concept of implant placement without flap elevation and exposure of the bony tissues was introduced. Flapless procedures have already been used for some time with tooth extractions and site preservation and have shown less morbidity. In addition, surgeons have also considered a flapless approach for immediate implants in order to preserve the vascular supply and existing soft tissue contours. Surgeons use either rotary instruments or a tissue punch to perforate the gingival tissues to gain access to bone.

When teeth are present, blood supply to the bone comes from three different paths: from the periodontal ligament, from the connective tissue above the periosteum and from inside the bone [6]. When a tooth is lost, blood supply from the periodontal ligament disappears, so that blood now comes only from soft tissue and bone. Cortical bone is poorly vascularized and has very few blood vessels running through it, in contrast to marrow bone. When soft tissue flaps are reflected for implant placement, blood supply from the soft tissue to the bone (supraperiosteal blood supply) is removed, thus leaving poorly vascularized cortical bone without a part of its vascular supply, prompting bone resorption during the initial healing phase.

The crestal bone area is considered a significant indicator of implant health [8]. Crestal bone is the area that bears the maximum stress around an implant. Blood supply to the crestal bone area is reduced around an implant compared with that of a natural tooth, because the blood vessels from the periodontal ligament are absent. Its major source of blood supply is from the periosteum covering the bone. Several studies have shown that mucoperiosteal flap elevation leads to bone resorption; however, there are few studies comparing crestal bone height between flapless and conventional flap technique.

The results of this study show that the mean difference in the bone loss for baseline to the third month for the flap group was 0.34 ± 0.05 and for the flapless group was 0.03 ± 0.004 (p = 0.000***). The results of the present study appear to concur with the findings of Tonetti and Schmid [9], as the cases treated with the flapless technique have shown significantly less bone loss compared with the cases treated with a conventional flap technique. Shamsan et al. [10] reported a mean crestal bone loss of 0.45 ± 0.22 mm in the flapless technique and 0.82 ± 0.09 mm in the conventional flap group. Gomez and Roman [11] supported the results of the present study by reporting that whenever it comes to marginal bone, higher bone loss rates usually occur with widely mobilized surgical flap sites where the interdental bone in the proximity to the implant is denuded from the periosteum thus affecting the nutrition of the bone and papillae, thus resulting in unpredictable degree of resorption of the interproximal marginal bone. Bhavita et al. [12] in their study showed that the overall average crestal bone resorption was 0.046 ± 0.008 on mesial aspect, 0.043 ± 0.012 on distal aspect with flapless technique, 1.48 ± 0.085 on mesial aspect and 1.42 ± 0.077 on distal aspect using with “open flap” technique. Sunitha and Sapthagiri [13] found that flapless surgery resulted in the nonsignificant crestal bone loss of (0.03–0.09 mm) on both proximal aspects during the healing period and after loading. Jeong et al. [14] observed mean marginal bone loss ranging from 0.0 to 1.1 mm with flapless technique over a period of 1 year. Becker et al. [15] also noted nonsignificant bone loss around implants placed with flapless technique until 2 years. Wood et al. [16] reported bone loss ranging from 0.23 to 1.60 mm in 4–6 months following flap elevation. Campelo and Camara [17] reported that bone resorption after using “with flap” technique is related to the thickness of the flap at the surgical site.

Job et al. [18] observed a crestal bone loss of 0.06 mm with “flapless” technique and 0.4 mm “with flap” technique over a period of 3 months. Nickenig et al. [19] found that radiographic evaluation of marginal bone levels adjacent to implants showed comparable results with flapless (0.7–2.4 mm) and flap surgery (2–3 mm) during the healing period. Similar findings were also reported by Al-Juboori et al. [20]. Jeong et al. [21] conducted their study in dogs, and after a healing period of 8 weeks they noted greater peri-implant bone height (10.1 mm) with flapless technique than at open flap site (9.0 mm). The cumulative success rate for implants placed using a flapless one-stage surgical technique varied from 74.1% to 100% after a 10-year period in a retrospective analysis done by Campelo and Camara [17]. In contrast, Pisoni Luca et al. [22] observed that there were no statistical differences in peri-implant bone resorption between the two groups, both at the basal record, implant loading and 3-year control. In our experience, there is definite advantage of flapless implant placement over the conventional flap technique in preserving the crestal bone loss. This is mainly because the crestal bone area which determines the implant health mainly depends on the periosteal blood supply [8]. Once the periosteum is stripped, there is definite loss of blood supply to the crestal bone area resulting in accelerated bone loss.

Studies quote several other advantages of flapless implant surgery, including preservation of circulation, soft tissue architecture and hard tissue volume, decreased surgical time and accelerated recuperation, allowing the patient to resume normal oral hygiene procedures immediately after the procedure [8]. In our present study, clinically patients in the flapless group have better comfort, painless postoperative days and early return to their routine day-to-day life as stated above.

Fear of pain is one of the most commonly cited anxieties associated with dental treatment. In particular, oral surgical procedures, including implant insertion, have been reported by patients to be among the most stressful and anxiety-provoking procedures in dentistry. Indeed, pain is a common complaint following dental implant surgery.

Despite the importance of pain during oral surgery for the patient and the clinician, there are few studies on the pain experienced following the placement of dental implants. Most studies fail to evaluate the intensity of pain and inflammation after surgery, and none have yet compared the patient’s perceived pain between different surgical alternatives. To evaluate the pain felt by patients, the current study used a VAS [9] which is the most widely used pain measurement instrument in many centers. The VAS is a simple, solid, sensitive and reproducible tool for assessing pain in a given patient at different points in time.

Flapless implant surgery is considered to offer advantages over the traditional flap approach, since bleeding is minimized, surgical time is shorter, and patient pain is reduced. However, studies contrasting patient outcome variables in support of these assumptions are lacking. Only one comparison has been made of flapless versus conventional flapped implant placement [23]. Therefore, the present study sought to explore patient pain/discomfort, using a subjective visual analog scale (VAS) to compare dental implant placement achieved by means of an atraumatic flapless technique with placement done with a conventional full-thickness flap technique.

The results of this present study show that there is a significant decrease in the VAS score of flapless group when compared with conventional flap with the difference being highest in the second postoperative day. Also the results of this present study show that the number of patients who felt no pain was also higher in the flapless group. These results are concurrent with studies by Shamsan et al. [10] who reported statistically significant higher mean pain severity and duration in conventional technique of implant placement compared to the flapless procedure.

The pain was also assessed by comparing the total number of analgesics taken between flapless and conventional flap group. The results of this study show that there is no painkiller taken by patients in the flapless group on the fourth day and fifth day. Except for the day of surgery, all the other postoperative days in flapless group had taken less number of analgesics when compared with conventional flap group. In accordance with the current study, Fortin et al. [24] also found that pain decreased faster and the number of patients who felt no pain was more in the flapless technique. They suggested that the objective of the flapless procedure is to reduce the invasiveness of surgery thereby reducing the surgical outcomes such as pain, edema and hematoma. This generally agrees with results reported by Chang et al. [25].

In the present study, the swelling assessment was done by the level of facial swelling which was determined by a modification of tape measuring method described by Gabaka and Matsumara [3]. The results of this present study show that there is no statistical difference in the level of swelling between these two groups. To our knowledge, there is no literature on swelling assessment in comparison between flapless and conventional flap techniques. Even though there is no statistical significance, the second postoperative day assessment value clearly shows that there is more swelling in the conventional flap group from their baseline value when compared with the flapless group.

Preoperative preparation is a critical component of the successful placement of implants using the flapless method [26]. Careful examination and diagnosis of the implant site, with radiographic assessment, is mandatory. Preoperative preparation may also include the use of computer tomography and sophisticated diagnostic software and the fabrication of a surgical template with a drilling guide for each implant.

There is a learning curve associated with every surgical procedure, after which it becomes routine. Appropriate case selection, meticulous planning, systematic surgical protocols and operator experience are required for success in flapless surgical techniques.