Single-Tooth Replacement in the Esthetic Zone With Ridge Expansion Osteotomy: A Clinical Report and Radiographic Results

The treatment of fractured, missing, or hopeless teeth within the esthetic zone has traditionally presented difficulties within the anterior region. Most clinicians have limited guidance in the evaluation and then selection of the appropriate restorative options in this esthetic zone. Recent investigations have focused on the diagnosis evaluation of a site prior to selecting a particular restorative option for tooth replacement.1 This selection criterion is based on a careful evaluation of the alveolar bone surrounding the site, particularly the integrity of the buccal plate, and the interproximal bone, which significantly influences individual tooth form and esthetics.

Sufficient density and appropriate volume of bone are crucial factors for successful implant treatment.2^,3 Only a few experimental studies have been performed that are aimed at the improvement of bone density and quality of the implant site.4^,5 

With implant-shaped instruments, the trabecular bone is compressed laterally. Furthermore, one experimental study that highlighted the course of osseointegration when using the osteotome technique is present in the literature.5 Few studies have been performed that are aimed at the radiographic results shown after the osteotome technique by computed tomography (CT) scan and assessment of objective improvement of bone density using Misch's classification.6 

The aim of this clinical case was to analyze the radiographic data of the osteotome technique on the change of bone density and to demonstrate the efficacy of the ridge expansion crest to bypass bone fenestrations of the buccal plate in the esthetic zone.

A 32-year-old female patient was referred to the authors to save her maxillary left lateral incisor. The tooth was slightly mobile (grade 1), nonvital, and extremely sensitive to palpation. Radiographic examination (panoramic) revealed a periapical radiolucency of tooth 2.2 associated with slight widening of the periodontal ligament space (Figure 1). The differential diagnosis included the possibility of a periapical granuloma or cyst. In areas of previously treated apical pathology, a surgical defect or periapical scar was also considered. In this case, the diagnosis was made of a periapical cyst.

The prognosis of the tooth was hopeless, and it was destined for extraction. After this tooth was extracted, curettage of the epithelium in the zone of apical pathology was performed.

The objective of treatment was to replace the lateral incisor with an implant-supported crown restoration without interfering with the integrity and topography of the adjacent gingival tissues.

A low-dose CT scan (Fanucci's protocol)7 for treatment planning and fabrication of a surgical/prosthetic guide was performed (slice thickness = 1.25; interval = 0.6; table feed = 11.25 mm × rotation; field of view = 0.6 mm; matrix = 512 × 512/200 Ma/80 kV). The CT scan revealed a great bone dehiscence of the buccal plate in the maxillary left lateral area with a bone density of D4 using Misch's classification6 (140 ± 20 HU) (Figure 2). The bone height was measured at the point of interest (2.2) both before and after implant placement in the reconstructed panoramic and parasagittal views.

Two months following extraction, expansion of the ridge was performed.

A midcrestal, full-thickness incision was performed. Once the flap was reflected, spiral drills were used to establish the future implant osteotomy sites. After establishing the initial implant osteotomy site, a sagittal osteotomy was outlined in the bone by scoring it with a No. 64 Beaver blade. The blade functions as a chisel and is tapped with a surgical mallet in small increments until a creation of a 1- to 3-mm-deep furrow along the length of the ridge. The seam is also made vertically to within 2 mm of the adjoining teeth. Once the crestal furrow and adjacent vertical bone releases have been defined, the bone chisel can be progressively driven deeper (Figure 3). Once the furrow is completed, the implant osteotomy site can be prepared to full dimension by osteotomes of increasing diameter (Friadent GmbH, Mannheim, Germany). Each instrument remained in the implant site for 1 minute before the next diameter was used. Finally, a Tapered Screw-Vent (Zimmer Dental, Carlsbad, Calif) of 3.7 × 13 mm was place in the distracted area. The flap was repositioned and sutured after the placement of the cover screw. Systemic antibiotics (amoxicillin + clavulanic acid) 2 gr/die were also prescribed for 4 days. Chlorhexidine gluconate 0.2% mouth rinse 3 times per day was prescribed for 10 days. Ice was applied postoperatively externally for 24 to 48 hours.

Five months after implant placement, the fixture was uncovered, and the abutment was connected. A low-dose CT scan (80 kV) was performed immediately after abutment placement. A bone-anchored fixed provisional prosthesis was then fabricated and put in place (Figure 4). The CT scan showed reconstruction of the buccal plate and enhancement of bone density from D4 (140 ± 20 HU) to D3 (380 ± 20 HU) according to Misch's classification (Figure 5). The final results demonstrated an increase in width of 4 mm after ridge expansion (from 9 mm to 13 mm) (Figures 2 and 5).

At 1-year follow-up, the implant met the Albrektsson et al criteria for success.8 No significant marginal bone resorption was seen around the implant 12 months after implant placement. The patient has been using this prosthesis with satisfactory function and great pleasure.

Only a few experimental studies have been performed that were aimed at the improvement of bone density and quality of the implant site.4^,5 Nkenke et al5 showed in a histological and histomorphometric analysis of implant osseointegration a benefit of the osteotome technique for increased bone-to-implant contact ratio in the early phase after implant placement. In contrast to the histomorphometrical data regarding increased bone-implant contact, the mechanical stability of implants inserted in condensed bone, true improvement of the bone density, and quality of the implant site are unknown.

By low-dose CT scan, we have shown in this case an increase in the width and density using the osteotome technique.

In conclusion, the results of this study have clinical relevance with regard to understanding the improvement of bone density and quality of the implant site, crucial factors for successful implant treatment.