PGO Scientific journal

Since the 1970s, modern implantology has been based on performing surgery with large incisions and large flaps in order to have a wide working field and to be able to see the area to be treated correctly. Gradually, the concepts of minimally invasive surgery have been established, where the surgical fields are increasingly smaller, with the consequent reduction of tissue damage, which improves the patient’s postoperative period and provides success rates similar to those obtained with classic protocols. treated using the punch technique. The present case demonstrates that flapless surgery using the punch technique is a safe and reproducible technique, however, the choice of patient and case are essential for successful treatment.

Surgical techniques in the field of oral implantology have undergone significant changes in recent decades. Early surgeries followed the protocol designed by Brånemark, which required an incision to be made in the mucosa, so that when the flap was closed the incision line and the suture were separated from the implant site, thus trying to avoid infection of the surgical site. ¹

The literature has shown evidence of crestal resorption following surgical procedures involving incision and elevation of a flap. Several authors have pointed out that during the first year after implant insertion there is peri-implant bone resorption in the crestal area of the alveolar bone.^1–5

The effect of surgical trauma caused by the lifting of a mucoperiosteal flap is the subject of scientific research. The debate revolves around the idea that the temporary interruption of the blood supply to the outer layers of the bone may cause increased resorption of the alveolar ridge.  In addition, regeneration of bone injured by implant surgery is negatively influenced when a pedicled mucoperiosteal flap is dissected.²

When teeth are present, the blood supply to the bone comes from 3 different pathways: from the periodontal ligament, from the connective tissue above the periosteum, and from within the bone. When a tooth is lost, the blood supply from the periodontal ligament disappears, so the blood now comes only from the soft tissue and underlying bone. Cortical bone, unlike medullary bone, is poorly vascularised and has very few blood vessels passing through it. When soft tissue flaps are exposed for implant placement, the blood supply from the soft tissue to the bone is removed, thus leaving the poorly vascularised cortical bone without a portion of its vascular supply, resulting in bone resorption during the initial healing phase. ³

Flapless surgery avoids detachment of the periosteum, which provides the blood supply to the peri-implant alveolar bone⁴ In addition, surgical trauma is minimal because the circular incision is very small, typically only 1 mm wider than the implant to be placed, so postoperative pain, inflammatory process and discomfort related to soft tissue trauma are greatly minimised.³

These advantages have led to the spread of the use of this type of incision, which has been the most widely used in recent years. ¹

However, this technique also has its limitations and complications, primarily limited visibility which increases the possibility of fenestration of the cortex, or placing the implant at an incorrect angulation.^1,5

The poor visibility and small operative field make this technique unsuitable for cases requiring hard or soft tissue volume augmentation techniques. In addition, the small operative field also makes it very difficult to visualise anatomical landmarks and vital structures; the potential for thermal damage secondary to reduced access during osteotomy preparation; a reduced ability to contour the bone topography to facilitate restorative procedures and to optimise soft tissue contours and, most importantly, the inability to manipulate the soft tissues to ensure circumferential adaptation of adequate dimensions of keratinised gingival tissue around emerging implants are the main drawbacks of the flapless technique.^1,5

62-year-old patient, with no medical history of interest, recently intervened for exodontia of 37, which had caused a lymphadenopathy due to the existence of a large carious lesion. The 36 had been absent for years. After three months, it was decided to remove the 38 because it was mobile and was causing the patient pain.

The anatomy and bone quality were then assessed with a cone beam computed tomography (CBCT), as well as a periodontal probe to measure the amount of keratinised gingiva. The ideal implant position was planned with the DentaScan software. The treatment plan consisted of placing two transmucosal implants using the flapless technique (Galimplant 3.5×8 mm, Galicia), given the good bone availability and adequate soft tissue quality.

Local anaesthesia was administered with articaine hydrochloride with epinephrine 1:100,000. Prior to surgery the patient was rinsed with 0.1 % chlorhexidine gluconate. The third molar was extracted without major complications using periostotomes and a straight botator. The alveolus was curetted post-extraction and filled with a fibrin sponge and sutured with simple PTFE/000 stitches.

Two circumferential incisions were then made in positions 36 and 37. A 5 mm diameter transmucosal circular scalpel was used to make a hole to match the diameter of the implant neck, avoiding soft tissue injury as much as possible. The cut was made with a circumferential rotating blade at low speed (100 rpm) and with saline irrigation.

The epithelial tissue was removed with a mosquito forceps and a periostotome.

Drilling was performed freehand without a surgical guide, following the drilling protocol proposed by the implant manufacturer. The two implants were then inserted manually with the aid of a dynamometric ratchet at a torque of 30 N, as recommended by the manufacturer. Once inserted, healing caps were placed, and no sutures were required at the implant site.

The postoperative regimen was: Ibuprofen 400-600 mg 6-8 hours and if the pain did not subside, add Paracetamol 500 mg every 6-8 hours orally between doses. In addition, Amoxicillin 1g every 12 hours for a week was prescribed.

As for the immediate post-surgery recommendations, it is important not to eat for 4-6 hours after the operation, continuing afterwards with a soft diet, preferably cold or at room temperature. It is advisable not to smoke or drink alcohol the days after surgery. It is important not to do any heavy physical work or exercise the following days, and to try to sleep with your head higher than your body, as well as to apply chlorhexidine gel to the operated area several times a day.

The surgery went very well. Thanks to this punch technique we drastically reduced the surgery time. The patient left the clinic very happy and reported no immediate pain or discomfort. After one week, no signs of oedema or swelling were observed in the area and the patient indicated that two days after surgery she stopped taking painkillers due to the absence of symptoms in the area.

Conventional surgery for implant placement involves direct access to the recipient site. However, the “blind” flapless technique, aided by preoperative three-dimensional planning, also allows correct positioning and angulation of the implant if the patient has been adequately assessed preoperatively.

The flapless procedure avoids detachment of the periosteum, thus also ensuring a better postoperative recovery for the patient. ⁴

In a cohort study conducted between 2003 and 2008 in Germany by Maier et al. ² 207 implants were placed in 80 patients. In total 104 implants were placed with the conventional flap elevation technique and 103 with the punch technique. In the first year only one implant was lost in each study group, giving a survival rate of 99.03%. After 1 year, a mean cumulative crestal bone loss of 0.24 +- 0.62 mm was measured. A mean bone loss of 0.55 to 0.57 mm was observed in the mucoperiosteal flap group, while a slight mean bone height gain of 0.09 to 0.49 mm was observed in the test group, a statistically significant difference. ²

A systematic review and meta-analysis by Cai H et al. ⁴ ccompared the long-term clinical performance of conventional flap and flapless implant surgery in edentulous patients over a follow-up period of at least three years. Evidence from a total of 8607 participants and 20428 implants indicated that there was no significant difference between implant survival rate, marginal bone loss and complication rate after flapless and conventional surgery. In addition, there were no significant differences between flapless and conventional techniques, both with the use of a surgical guide and the freehand method during the follow-up period of three years or more.

In another 15-month follow-up study by Wadhwa, et al. ⁵ showed that none of the implants placed with both techniques had bone loss >1.5 mm after the first year of loading. The results of the present study showed that with the flapless technique, the change in crestal bone height in both proximal aspects was negligible in the first 9 months. After 15 months the mean crestal bone loss was 0.046 ± 0.008 mm in the mesial aspect, 0.043 ± 0.012 mm in the distal aspect with the flapless technique and 1.48 ± 0.085 mm in the mesial aspect, 1.42 ± 0.077 in the distal aspect with the conventional open “flap technique”.

Information from a literature review evaluating the clinical performance of implants in 14 studies, which had a mean observation period of 19 months, showed a high survival of implants placed with a flapless technique. A survival rate of 98.6% based on prospective cohort studies suggests the clinical efficacy of the technique.⁶

As the literature states in the “flapless” technique, the blood supply remains intact, which facilitates the maintenance of nutrition, a critical factor in preventing initial bone loss around the implant.

This also helps to maintain the soft tissue architecture and hard tissue volume. Thus, recovery is accelerated, allowing the patient to immediately resume normal hygiene procedures due to the absence of sutures. According to previously published studies, early plaque control plays an important role in promoting the health of the peri-implant mucosa and also eliminates the second surgical phase, thus reducing the overall working time, the number of visits and the materials to be used. ⁵

These advantages may contribute to a comparable long-term clinical performance between flapless and conventional implant surgery. Therefore, the flapless technique can be considered a valid alternative that does not compromise the long-term results of implant treatment. Furthermore, although peri-implant bone gain was rarely observed in both groups, flapless surgery may ensure better patient comfort during postoperative recovery due to less oedema and pain. ⁴

Today, flapless surgery is in line with the progress of minimally invasive surgery in general medicine. However, not all cases can be performed with this technique; each case has to be studied individually. It is generally accepted that patients with an adequate amount of alveolar bone and keratinised tissue (i.e. a minimum of 6 mm width) can be treated by flapless implant surgery. Also the recipient site must be free of soft tissue debris or concavities after tooth extraction, otherwise a mucoperiosteal flap has to be performed.⁴

Practitioners should be aware of the risks and benefits related to the flapless technique. In addition, preoperative analysis with CBCT is recommended for ideal treatment planning.

Flapless implant surgery and the conventional approach with flap elevation have comparable results in terms of long-term implant survival rate, marginal bone loss and complication rate. In addition, guided or freehand insertion does not significantly affect the long-term effects of flapless surgery compared to the conventional approach.

Therefore, the flapless or punch technique is a valid alternative to be used in patients with adequate bone and soft tissue conditions. However, the surgeon’s experience will be key to the success of the treatment.

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2. Maier F-M. Initial Crestal Bone Loss Af ter Implant Placement with Flapped or Flapless Surgery—A Prospective Cohort Study. Int J Oral Maxillofac Implants. 2016;31(4):876–83.
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4. Cai H, Liang X, Sun DY, Chen JY. Long-term clinical performance of flapless implant surgery compared to the conventional approach with flap elevation: A systematic review and meta-analysis. World J Clin Cases. 2020;8(6):1087–103.
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