Lu LIU, Wenhui YU, Xitao LI, Hui ZHAO, Jianjun YANG

1. The Affiliated Hospital of Qingdao University, Department of Oral and Maxillofacial Surgery, Qingdao 266003, China; 2. School of Stomatology of Qingdao University, Qingdao 266003, China

Abstract [Basckground] This case report presented a methodology for immediate implantation in the esthetic zone with a facial bone defect along with flap surgery, guided bone regeneration, and non-submerged healing. [Case presentation] A 27-year-old female patient was complaining of the aesthetic complication that was caused via metallic staining of the neck of ceramic crowns in the maxillary right anterior region for one year. She has experienced immediate implantation along with flap surgery, guided bone regeneration (GBR), and non-submerged healing. The torque of the implant reached to the 35 N·cm to confirm primary stability. Six months after surgery, the healing abutment and the implant were fixed, the gingiva was healthy in the surgical area, and the nearby teeth and the opposite teeth were normal. [Results] The results of cone-beam computer tomography (CBCT) revealed that bone defects were filled with the newly formed bone. At the same time, the final impressions accomplished, and an all-ceramic crown was fit-placed. As a whole, the patient satisfaction rate was high. [Conclusions] Immediate implant placement with flap surgery, GBR, and non-submerged healing with a facial bone wall defect in the esthetic zone is an achievable process.

Key words Case report, Immediate implants, Labial bone defect, Flap surgery, Guided bone regeneration, Non-submerged healing

1 Background

The idea of immediate implantation was first proposed by Professor Wilfried Schulteetal.[1]in 1978. They explained that implants should be quickly implanted in the fresh extraction socket within 24 h after extraction. In 2009, Chen and Buser[2]introduced a new time limit for various implantation techniques. They proposed that immediate implantation is carried out instantly after the extraction of the tooth. Immediate implantation is the most preferred choice for doctors and patients because it can retain the contour of the alveolar ridge post tooth extraction, overcome the course of surgery, decrease the number of visit, and save expenses. Over the past several decades, numerous studies have been confirmed that immediate implantation is a feasible and reliable method for the restoration of missing teeth[3-4]. Its long-term success rate is similar to that of delayed implantation, and it has become a conventional implantation technique in the aesthetic field[5-7].

Based on the cone-beam computer tomography (CBCT) studies, the Consensus Conference clearly recommended that when immediate implantation can be considered and used[8], including (i) an intact facial bone wall at the extraction site (> 1 mm), (ii) a gingival biotype (thick), (iii) absence of severe infection at the site of extraction, and (iv) a sufficient volume of bone (extraction site) allow the insertion of the implant in a precise 3D position for obtaining enough primary stability[8]. However, the underlined conditions are rarely encountered in the anterior maxilla. On the basis of different CBCT studies, a thick wall phenotype infrequently exists in the anterior maxilla region[9-11]. Brautetal.[9]evaluated the thickness of the facial bone wall at different positions of the tooth in the region of the anterior maxilla. Specifically, 4.6% consist of thick wall phenotypes (> 1 mm) at the site of the central incisor. And 34 successively extracted maxillary central incisors have been studied which revealed that 18 sites (52%) showed bone defects including fenestration or dehiscence[12]. When the anatomy of the facial bone has been lost, it negatively influenced aesthetics and is usually a significant factor for the complications of aesthetic implantation and its failures[13-16]. Current research suggested that early implant placement along with flap surgery, guided bone regeneration (GBR), and submerged healing post healing of soft tissue[17]. Therefore, the underlined procedure has been proposed for treating sites that consist of non-intact facial bone or a thin bone wall phenotype[8,17].

The current case report demonstrated immediate implantation along with flap surgery, GBR and non-submerged healing with labial bone wall defect in the esthetic zone. We are intended to analyze the clinical influence and new treatment in sites having a deficiency of an intact facial bone wall.

2 Case report

A 27-year-old female patient complained of an aesthetic problem caused from metallic staining of the neck of ceramic crowns in the maxillary right anterior region for one year. On intra-oral examination, the exposure of metals was found to be observed in the neck of #12 with no clear loosening or pain. Fistula and swelling were not observed on the labial gingival, as depicted in Fig. 1A. There was no considerable familial history.

CBCT study showed that the filling of the root canal was not dense in the #12. It also revealed that the area was low dense around the apical of the tooth and local resorption was noticed at the apical the root. On the root upper side, the labial bone wall thickness was measured which was about 1.68 mm, as depicted in Fig.1B. The labial bone plate was almost not found on the lower part of the root.

Note: A. the exposure of metals was found to be observed in the neck of #12; B. cone-beam computed tomography revealed the area was low dense around the apical of the tooth and the labial bone plate was almost not found on the lower part of the root.

Immediate implant placement on tooth #12 along with flap surgery, GBR, and non-submerged healing were recommended to solve her problem. Presurgery, a suitable implant, and healing abutment were chosen based on CBCT results, as depicted in Fig.1B. The patient agreed with the given treatment and signed the informed written consent.

Prophylactic antibiotic therapy (cephalosporins and metronidazole) was given 60 min pre-surgery. Intraoral antisepsis along with iodophor (2.5%) was used rinse for about 2 min, followed by the administration of local anesthesia. The tooth extraction was carried out by a minimally invasive surgical procedure. The labial vertical releasing incision at the middle of the tooth #13 ended more than 5 mm beneath the mucogingival junction. Next, the proximal and distal gingival valley of tooth #12 was incised to the crest of the alveolar ridge. On the side of the labial, a full-thickness mucoperiosteal triangular flap was increased, and the palatal mucoperiosteum was slightly increased for uncovering the alveolar crest. Then, the careful debridement of the extraction socket was carried out. The implant bed preparation was carried out at the base of the socket close to the palatal wall and autogenous bone collection was performed in the socket drilling, followed by the selection of implant (Dentium, South Korea) which was set into the fresh socket. The successful primary stability was confirmed by the torque which has been reached to 35 N·cm. The implant was placed slightly near to the palatal bone wall to predetermine the permanent prosthesis incisal edge, left a jumping distance to the internal surface of the labial bone wall. The defect of labial could be observed, as depicted in Fig.2. A suitable healing abutment (Dentium, South Korea) was screwed on the implant to a height of 1 mm higher than the mucosa after suture. The filling of the labial plate defect was carried out with artificial bone grafts (Tianbo, Beijing, China) mixed autogenous bone chips which were collected during socket drilling, followed by the covering of the bone graft surface with Haiao absorbing collagen membrane (Yantai Zhenghai Bio-Tech Co., Ltd., Shandong, China). The graft materials were not sited into the space between the implant and the socket walls. Moreover, the labial and palatal mucoperiosteal flaps were interrupted sutured around the abutment without tension. he removal of sutures was performed after 10 d.

Note: A. flap surgery; B. the implant was placed, and the bone defect was visible around the implant; C. the labial defect could be seen; D. GBR; E. the flap was sutured without tension to ensure that the gingival periosteum tightly surrounded the abutment base and closed the socket.

Six months after surgery, the healing abutment and the implant were fixed while the gingival mucosa was found to be healthy in the surgical area, and the neighboring and the opposite teeth were also normal. Then the CBCT showed the formation of labial bone. The bone defects were occupied with the anew generated bone. Instantaneously, the impression was performed. After 14 d, an all-ceramic crown was applied (Fig.3). The criteria were set by Belse[18]and include pink esthetic scores (PES) and white esthetic scores (WES) for the aesthetic analysis. The total score was 10 and the threshold was set at 6. The PES and WES were satisfactory (PES: 8, WES: 9). The aesthetic satisfaction of patients was evaluated via a visual analog scale (VAS)[19]. The satisfaction score ranged from 0 to 10. In the current case, the aesthetic satisfaction of the patient was great (the VAS score was 9.5).

3 Discussion

The improvements in the field of implantology speed up the placement of dental implantation into a fresh extraction socket which has been introduced as an alternative therapy in order to late the placement. Only after the conditions are required for the indication are met, the immediate post-implantation operation might have a high rate of stability and significant aesthetic results[17]. The primary stability is considered to be crucial for successful implantation that accomplishes all criteria such as immobility, absence of infection, and suitable width of the connected gingiva. In the current case, the torque of the implant is 35 N·cm and the significant implantation depth is at least 4 mm, which confirms the significant primary stability of the implant.

Moreover, the current case selected the flap procedure. During the implantation surgery, the labial gingival mucoperiosteum was cut and opened and turned over after the extraction of the affected teeth. Furthermore, there was varying (greater or less) inflammatory granulation tissue in the alveolar fossa and on the surface of the opened gingival mucoperiosteal flap, specifically in the coronal point of the gingiva,i.e., gingival margin position and gingival papilla of the mucoperiosteum. In this view, we speculated that immediate implantation can not only reduce the timeframe of treatment but also extensively eliminate the inflammatory tissue, thus ending the destruction of the inflammatory tissue to the soft and hard tissue around the implant bed. Because we chose the incision of the adjacent labial side oblique to the vestibular sulcus and beyond the subgingival 5 mm, the angular flap was fully free and could slide to the palatal side when the healing abutment was placed and sutured the soft tissue, it could ensure that the labial gingival mucoperiosteal flap was tightly sutured around the healing abutment under tension-free conditions. The angular flap is less traumatic than the trapezoidal flap and will not affect the blood supply. The design of the angular flap can significantly diminish the gingival soft tissue tension during dental suturing so that the gums on the lip and palate can be compactly sutured encircling the healing abutment for the development of a significant biological seal[20].

In 1994, the non-submerged healing approach was used in immediate implant surgery by Lang and achieved satisfactory results[21]. In current decades, several studies have been indicated that the clinical outcomes of non-embedded healing in the immediate implant have been generally known[22-23]. In earlier studies, the submerged healing has been used by nearly all cases of bone grafting. The main objective is to avoid exposure to bone graft material and decreases the influence of the external environment on GBR[24]. Although, in the current case, the immediate implantation along with flap surgery, GBR, and non-submerged healing were performed in the treatment, the bone graft material was not exposed. In the initial stage, the healing of soft tissue wounds was observed.

The main objectives of implantation in the anterior maxilla are remarkable aesthetics having a high rate of success and low risk of complications. The correct 3D position of the implant is highly crucial for obtaining significant effects of an aesthetic implant. In the existing case, the implant was found in the accurate 3D position and significant initial stability of the implant was obtained. One year after completion of the repair, the implant maintenance rate was almost 100%, the stability of soft and hard tissues was also observed, the aesthetic repair effect was satisfactory, and the satisfaction rate of the patients was high.

4 Conclusions

Taken together, the current case can complete tooth extraction, implant insertion, bone augmentation, and soft tissue plasty above the implant with a single surgery, which makes simpler the surgical procedure, decreases the pain of the patient, and reduces the timeframe of the treatment as well as medical expenditures. In brief, the underlined procedure has remarkable clinical application values.