Retrospective Study: Lateral Ridge Augmentation Using Autogenous Dentin: Tooth-Shell Technique vs. Bone-Shell Technique

Abstract

In the literature, autogenous dentin is considered a possible alternative to bone substitute materials and autologous bone for certain indications. The aim of this proof-of-concept study was to use autogenous dentin for lateral ridge augmentation. In the present retrospective study, autogenous dentin slices were obtained from teeth and used for the reconstruction of lateral ridge defects (tooth-shell technique (TST): 28 patients (15 females, 13 males) with 34 regions and 38 implants). The bone-shell technique (BST) according to Khoury (31 patients (16 females, 15 males) with 32 regions and 41 implants) on autogenous bone served as the control. Implants were placed simultaneously in both cases. Follow-up was made 3 months after implantation. Target parameters during this period were clinical complications, horizontal hard tissue loss, osseointegration, and integrity of the buccal lamella. The prosthetic restoration with a fixed denture was carried out after 5 months. The total observation period was 5 months. A total of seven complications occurred. Of these, three implants were affected by wound dehiscences (TST: 1, BST: 2) and four by inflammations (TST: 0, BST: 4). There were no significant differences between the two groups in terms of the total number of complications. One implant with TST exhibited a horizontal hard tissue loss of 1 mm and one with BST of 0.5 mm. Other implants were not affected by hard tissue loss. There were no significant differences between the two groups. Integrity of the buccal lamella was preserved in all implants. All implants were completely osseointegrated in TST and BST. All implants could be prosthetically restored with a fixed denture 5 months after augmentation. TST showed results comparable to those of the BST. Dentin can therefore serve as an alternative material to avoid bone harvesting procedures and thus reduce postoperative discomfort of patients.

Keywords: autogenous; bone graft; dentin; implant; tooth-shell technique.

Figure 1

Clinical procedure of the bone-shell technique. (a): The graft was harvested with a MicroSaw-Kit^® from the retromolar region/linea obliqua. (b,c): The bone block graft was split into two thin bone slices with a diamond disc. (d,e): The thin bone slices were fixed at a distance from the alveolar ridge with osteosynthesis screws. (f): The cavity between the fixed bone slice and the alveolar ridge was filled with autologous bone chips.

Figure 2

(a): The illustration shows the removal of debris and foreign material, such as restorations and root filling material, as well as the periodontal ligament, from the root surface with a coarse diamond bur under water cooling. (b): Dentin shell obtained from the root dentin with a diamond cutting disk. (c): Sterile disposable dentin grinder (Smart Dentin Grinder) for the particulates of dentin. (d): Particulate treated dentin.

Figure 3

Clinical procedure of the tooth-shell technique. (a): Inserted implants at the site of tooth 25 and tooth 26 with vestibular bone missing. Dentin shell fixed (blue arrows) with osteosynthesis screws to the vestibular aspect of the implant. (b): The hollow space created between the dentin shell and implant was filled with particulate dentin (green arrows).

Figure 4

(a): A cone-beam computed tomography (CBCT) in the sagittal plane shows an implant regio 11 with the tooth-shell technique (TST) at the time of the implant exposure. The integrity of the buccal lamella is visible. The dentin shell does not appear to show any resorption. (b): The same CBCT in the axial plane with the implant in region 11 and another implant region 21. Two buccal dentin shells are clearly visible. (c): This figure shows a CBCT in the sagittal plane of an implant region 12 with BST at the time of implant exposure. At this plane, the complete integrity of the buccal lamella can be seen. The bone shell is no longer visible and appears to have undergone replacement resorption. (d): The same implant in the CBCT in the axial plane. No bone shell can be seen.