Original study - ZZI 01/2013

Lateral bone augmentation applying different biomaterials

M. Merli1, M. Moscatelli1, A. Mazzoni2, M. Merli1, G. Mariotti1, M. Nieri3

A clinical and histological evaluation of a case report

Introduction: This paper describes the treatment of horizontal osseous defects around implants in a one-stage split-mouth approach in a middle-aged female patient.

Method and Material: The same identical reconstruction technique was performed in both surgical sites using different biomaterials: a ? -tricalciumphosphate (Ceros TCP granules) grafting material and a porcine, collagen pericardium resorbable membrane (Remotis) were employed on the test side and a deproteinized, bovine bone matrix (Bio-Oss) and a porcine, collagen resorbable membrane (Bio-Gide) on the control side. Bone substitutes were mixed with autologous bone (approximately 10 %) harvested during implant insertion procedures.

Results: Substantial bone regrowth was evident in both ridges, although only the test side underwent complete regeneration. Histological examination of the regenerated areas showed the presence of mature bone organized around particles of biomaterial during the incorporation phase.

Conclusion: Both therapeutic approaches have proved favorable in terms of covering the initially exposed implant threads.

Keywords: ?-tricalciumphosphate; bone augmentation; collagen membrane; dental implants; deproteinized bovine bone matrix

Citation:

Merli M, Moscatelli M, Mazzoni A, Merli M, Mariotti G,
Nieri M: Lateral bone augmentation applying different
biomaterials A clinical and histological evaluation of a case report. Z Zahnärztl Implantol 2013;29:70-79.
DOI 10.3238/ZZI.0070-0079

Introduction

A principle anatomic condition for implant therapy is the presence of sufficient bone volume to result in implant stability. Clinical situations in which the bone quantity is inadequate very often require regenerative bone therapy. Bone augmentation procedures may be carried out prior to (two-stage procedure) or simultaneously to implant placement (one-stage procedure) and these procedures can be performed using different materials and techniques [8].

The augmentation procedure is classified as horizontal or vertical bone augmentation according to the bone-type defect [8]. In one-stage horizontal bone augmentation treatments, resorbable collagen barrier membranes in combination with a variety of graft materials, such as autogenous bone, allografts, xenografts and alloplastic materials are often used [7, 13, 14, 15, 17, 18, 21]. In addition, the titanium implant surface characteristics may play a role in bone regeneration in dehiscence-type defects, such as the development of sandblasted/thermal acid-etched surface technology [16]. This new conditioning process, performed immediately before surgical placement, increases the implant surface hydrophilic [5, 19]. In animal studies, the conditioned surface reduced the healing period and increased bone apposition in the early healing phase [5, 19].

There are several systematic reviews that examine horizontal bone augmentation [7, 8]. However, in humans, one-stage randomized clinical trials (RCTs) are scarce [1, 9, 10, 11]. Recently, a RCT was published comparing a synthetic bioresorbable polyethylene glycol hydrogel (PEG) membrane and a standard collagen membrane grafted with natural bone matrix of bovine origin [11]. No differences were detected in the percentage of vertical bone defect filling after 6 months, with the exception of a greater frequency of soft tissue complications observed with the PEG membrane, and a shorter preparation and application time for the PEG hydrogel membrane [11].

Another RCT compared the amount of newly formed bone in sites with the application of a cross-linked collagen membrane versus that of a native collagen membrane for the treatment of dehiscence-type defects at titanium implants [1]. A natural bone mineral of bovine origin was also used. Four patients in the cross-linked membrane group prematurely discontinued the study (3 due to wound infection) and one patient in the native collagen group discontinued the study due to wound infection. No statistical differences regarding the change in vertical defect length, the change in horizontal defect width and the quality of newly formed tissue at the fourth month were observed.

Presently, there are no studies that compare a standard collagen membrane and natural bone mineral of bovine origin directly with another system consisting of multilayer, porcine pericardium natural collagen membrane and ?-tricalciumphosphate for horizontal bone augmentation [4, 20].

The aim of this case report is to investigate these two different procedures in a split-mouth approach using a novel implant surface with increased hydrophilicity.

 

Methods and Material

A 43-year-old female patient, non-smoker, classified as ASA-Physical Status (PS) I (good systemic health status) [12] exhibited missing first molars in the mandible. The two areas presented similar bone defects (Fig. 1–3). After scaling and root planing an integrated treatment plan was established based on the collected data and patient desires.

The research was conducted in accordance with ethical principles, including the Declaration of Helsinki and the patient gave a written consent according to the above mentioned principles.

The substitution with crowns supported by implants on both sides was preceded by orthodontic treatment. The uprighting of second molars was obtained using miniscrews to improve and accelerate the orthodontic movement.

The patient underwent intravenous conscious sedation and received local anesthesia in both sides of the mandible during the surgical procedure for guided bone regeneration with simultaneous implant insertion. Mucoperiosteal flaps, involving interproximal teeth, with one vertical incision mesial to the second premolar were raised to expose the underlying bone defects. The implant sites were prepared using cylinder burs, gradually increasing the diameter under copious saline irrigation. INICELL implants (Thommen Medical AG, Waldenburg, CH, Switzerland) were conditioned chairside and positioned both in the test and control sites, maintaining a safe distance of 2 mm from the roof of the mandibular canal. INICELL implant surface is a further development of sandblasted/thermal acid-etched surface technology [5, 19]. The one wall dehiscence-type defects were filled with a mixture of the bone substitute (approximately 90 %), autologous bone (approximately 10 %) harvested during implant insertion procedure using disposable filters, and patient’s blood.

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