Abstract
Bone resorption and remodelling are inevitable sequelae of dental extraction and begin immediately after the extraction procedure. The buccal plate is especially predisposed to these phenomena, and if affected, may result in an increased risk of facial soft-tissue recession and other adverse clinical effects that may decrease the predictability of implant placement or impair the final aesthetic result. Buccal plate preservation is a new technique aimed at maintaining or improving the appearance of the soft and hard tissues after dental extraction procedures. The aim of this case series is to evaluate the effectiveness of this technique to maintain or improve soft tissue contours in aesthetic areas when used in conjunction with immediate implant placement. Buccal plate preservation as described may help to maintain or improve the appearance and contours of the ridge after tooth extraction, laying the groundwork for optimal functional and aesthetic replacement of the missing tooth with an implant-supported prosthesis.
Marked alterations in hard and soft tissue contours are expected after tooth extraction, particularly in the anterior maxilla. These may lead to a remodelling of the alveolar socket with profound changes in the buccal-palatal dimension as shown by Schropp et al. and Botticelli et al. Even when minimal, such resorption usually has significant adverse clinical effects, particularly in the aesthetic zone. Despite successful osseointegration of a dental implant, an anterior implant restoration may be judged to be a failure if the soft tissue appearance is poor. Although it has been postulated that placing an implant into a fresh extraction socket may counteract buccal plate resorption following dental removal, recent studies in humans and experimental animals have not validated this hypothesis. Ferrus et al. concluded that the thickness of the buccal bony wall, as well as the dimension of the horizontal gap significantly influence the hard tissue alterations following immediate implant placement into fresh extraction sockets. Tomasi et al. suggested that when immediate implantation is planned, the thickness of the buccal bony walls in the extraction sites and the tri-dimensional positioning of the fixture into the sockets must be considered, since these factors, besides others such as age, smoking and reason for extraction, can influence the hard tissue changes during healing. Connecting a provisional crown immediately after implant insertion and grafting of the facial peri-implant marginal defect with bone or bone substitutes have also been cited as factors influencing the final outcome. In aesthetic areas, any minimal alteration of soft or hard tissue may compromise the final result, thus, preservation of alveolar ridge and soft tissue contours by placement of particulate bone-graft material underneath the soft tissues in a surgically created pouch adjoining the buccal plate has been advocated to prevent recession of the facial wall of the extraction socket without interfering with its natural, self healing process. This technique, termed buccal plate preservation was originally used when delayed implant placement was planned. It has since also been used effectively in conjunction with immediate implant placement and provisionalisation. The purpose of this article is to report the results of a small case series of patients who underwent buccal plate preservation in conjunction with immediate insertion and provisionalisation of the implant with the aim of maintaining or improving the soft tissue contours and appearance in aesthetic zones areas after tooth extraction.
Materials and methods
10 consecutive patients seeking treatment in two private dental offices participated in this study. Criteria for inclusion included: ASA I physical status; non smokers; one unrestorable, periodontally healthy tooth requiring extraction from the anterior maxilla (first bicuspid to first bicuspid zone); and intact 4-wall extraction socket following extraction. Appropriate informed consent was obtained. The study was considered exempt from institutional review board regulations as per current regulations for research completed solely in a private practice located in Italy.
All patients underwent extraction and buccal plate preservation ( Fig. 1 a–c ) followed by immediate implant placement and provisionalisation. All teeth were extracted atraumatically with first bicuspids electively sectioned with rotary instrumentation and extracted in two separate pieces. The sockets were thoroughly debrided with hand instruments to remove any residual granulation tissue. A thin periosteal elevator was used to reflect the soft tissue buccal to the bony buccal plate on the facial aspect of the middle of the socket in a full-thickness manner, following a corono-apical direction, thereby creating a ‘surgical pouch’. Extreme care was paid to avoiding tearing the soft tissue. The dissection was advanced beyond the mucogingival line to approximately two-thirds the depth of the socket, and the pouch was expanded in the mesio-distal direction to stretch the soft tissues away from the underlying bony plate. Granules of bovine xenograft (Endobon ® Xenograft Granules, BIOMET 3i , Palm Beach Gardens, FL, USA) were hydrated with saline and inserted into the pouch by mean of a small periosteal elevator ( Fig. 1 c). Additional graft material was added and compressed until adequate filling of the pouch was achieved without overstretching the soft tissues. Care was taken to avoid the migration of the graft material too far apically, where the mucosa is more flexible and thin, though should this occur, the graft material can be repositioned using manual digital pressure. Since some resorption and exfoliation of the graft is always possible, the authors recommend that the final appearance of the soft tissues should mimic or even slightly exaggerate the appearance of the root eminence of the tooth prior to extraction. A total of eight 4 mm diameter and two 3.25 mm diameter tapered implants were placed according to the manufacturer’s protocol (BIOMET 3i , Palm Beach Gardens, FL, USA), engaging the palatal wall and the native bone above the alveolus ( Fig. 1 b). The gaps between the buccal bone and the implant surface were filled with the same grafting material ( Fig. 1 c). At the end of the surgical procedure, a transfer coping was made ( Fig. 2 a ) and a pick-up impression was connected to the surgical stent with self-curing resin to register the position of the implant ( Fig. 2 b), which was transferred to a laboratory model. A temporary healing abutment was placed on each implant. Custom abutment and temporary resin crowns were fabricated and delivered to the patients immediately following the surgical procedure ( Fig. 3 ). Suturing was not performed in any patient and no attempts were made to obtain primary closure. The patients were maintained on a liquid diet for 1 week postoperatively followed by a soft diet for 4 weeks. Chlorhexidine gluconate oral rinse was prescribed for 2 weeks to enhance plaque control. The final restoration was delivered at the 3-month postoperative interval ( Fig. 4 a and b ).
