A comparison of three calcium phosphate based space fillers in sinus elevation: a study in rabbits

in International Journal of Oral & Maxillofacial Implants (2013)

Aim: Sub-sinusal bone regeneration procedures are reliable procedures that are known to be efficient with the use of biomaterials alone. Nevertheless, many types of biomaterials are available, and their ... [more ▼]

Aim: Sub-sinusal bone regeneration procedures are reliable procedures that are known to be efficient with the use of biomaterials alone. Nevertheless, many types of biomaterials are available, and their efficacy in terms of bone formation and resorption rate have rarely been compared. This study aimed to compare the bone formation, resorption rate, osteoconductivity and 3D volume changes of three biomaterials often used for alveolar ridge augmentation. Materials and Methods: Rabbits underwent a double sinus lift procedure using three different types of space fillers: bovine hydroxyapatite (BHA), beta calcium phosphate (ß-TCP) and biphasic calcium phosphate (BCP). Animals were sacrificed at 1 week, 5 weeks and 6 months. Samples were subjected to X-ray microtomography and histology. Qualitative analysis was performed on non-decalcified sections, and quantitative histomorphometric analysis was conducted using SEM. Volume variations of bone augmentations were calculated at different time points. Results: All three particulated biomaterials proved to be effective in promoting osteogenesis. At 6 months, biomaterial resorption rates were significantly different across the 3 groups (p<0.0001). The highest resorption rate was found with β-TCP, in which only 6.7% of the baseline particle surface remained. At 6 months, bone was in close contact with the BHA particles, constituting a composite network; in contrast, BCP particles were often surrounded by soft tissues. In each group, no significant difference in volume variations were found at the different time point. Conclusions and clinical implications: Despite the limitations of the study, the three particulated space-filling biomaterials proved to be efficient to promote osteogenesis. High resorption rates and complete replacement of the biomaterials by bone seemed to withstand intrasinusal pressure. Further investigations in humans should consider longer follow-up periods. [less ▲]

Patient morbidity after socket preservation using a connective tissue graft versus a bilayer collagen matrix: Preliminary results of a comparative Randomized Control Trial.

Poster (2012, June)

INTRODUCTION AND AIM: The present randomized controlled trial compared socket preservation procedures using bovine hydroxyapatite (Bio-Oss®, Geistlich, Switzerland) covered with a connective tissue graft ... [more ▼]

INTRODUCTION AND AIM: The present randomized controlled trial compared socket preservation procedures using bovine hydroxyapatite (Bio-Oss®, Geistlich, Switzerland) covered with a connective tissue graft (CT) versus a bilayer collagen membrane (CM) (Mucograft®, Geistlich, Switzerland), placed from buccal to palatal in split-thickness pouches in order to seal the extraction site and to potentially thicken the buccal mucosa. The aim of this present abstract was to evaluate post-operative complications and patient-centered outcomes of the two independent surgical protocols. METHODS: This randomized controlled trial included 26 patients (16 female, 10 male) aged from 20 to 69 years (mean: 42.6, SD: 12). 26 teeth were extracted atraumatically and the 2 distinct surgical protocols were applied randomly. Patients filled out a VAS form 1 week after the surgery to evaluate their level of discomfort and post-operative pain. Drug intakes as well as complications were also recorded. RESULTS: No statistical significant differences were found between the 2 groups in terms of post-operative complications (bleeding) and post-operative pain. The consumption of painkillers after the surgery decreased over time but was similar in the two groups. CONCLUSION: According to the preliminary results of the present RCT, none of both protocols seemed to induce significant post-operative pain and discomfort. There was no difference between the two procedures regarding post-operative complications and patient centered outcomes. [less ▲]

Early Implant placement in socket preservations: 12-month results of a prospective case series.

Poster (2012, June)

Objectives: The aim of this study was to evaluate the clinical and histological outcomes of implant placed after socket preservation procedures in the esthetic zone. Implant survival rate and biological ... [more ▼]

Objectives: The aim of this study was to evaluate the clinical and histological outcomes of implant placed after socket preservation procedures in the esthetic zone. Implant survival rate and biological complications were recorded during a follow-up period of 1 year. Materials and methods: A series of 12 patients needing the replacement of a single tooth in the esthetic zone were included in the present study. The hopeless teeth were extracted atraumatically, the sockets were filled with bovine hydroxyapatite (0.25-1mm particles) and the sites were covered with a saddled connective tissue graft. After a healing period of 3 months, biopsies were retrieved in the socket preservation sites and implants were placed. The patients were followed for a period of 1 year. Results: The etiologies of tooth loss were : endodontic (9), caries (1), periodontal (1), and traumatic (1). A total of 12 implants (10 incisors, 2 premolars) were placed on 12 patients (6 men / 6 women) aged from 24 to 61 (42,3 – 11,91). All implant reached an adequate primary stability (> 20N/cm2). 7 out of 12 implants were immediately restored with a temporary crown, and the définitive restorations were successfully placed in all cases. After a follow-up period of 1 year, all implants fulfilled strict success criteria for dental implants with regard to osteointegration, including the absence of peri-implant radiolucency, implant mobility, suppuration, and pain and no further complications occurred. Out of 12 sites only 7 biopsies were retrieved for histological analyses. New bone was found in the apical third of the socket in every specimen, in the mid-third in only 3 specimen and no bone was found in any of the spécimen in the more cervical third of the socket. Conclusion: The results from this prospective case series suggest that early implant placement in extraction socket site seems to display good clinical outcomes despite the incomplete bone regeneration in the socket at 3 months. [less ▲]

Patient morbidity after 2 different surgical protocols to treat miller class I recession in the anterior maxilla: A Comparaitive Ramdomized Control Trial.

Conference (2012, June)

Bone Regeneration Using Porous Titanium Particles versus Bovine Hydroxyapatite: A Sinus Lift Study in Rabbits.

in Clinical Implant Dentistry & Related Research (2011)

Aim: The first objective of this study was to qualitatively and quantitatively assess the bone formation process, particularly the long-term behavior and three-dimensional volume stability of subsinusal ... [more ▼]

Aim: The first objective of this study was to qualitatively and quantitatively assess the bone formation process, particularly the long-term behavior and three-dimensional volume stability of subsinusal bone regeneration, using titanium (Ti) or bovine hydroxyapatite (BHA) granules, in a rabbit model. The second objective was to evaluate the effect of the hydration of the BHA particles with a therapeutic concentration of doxycycline solution on the osteogenesis and biomaterial resorption. Materials and Methods: Rabbits underwent a double sinus lift procedure using one of three materials: grade 1 porous Ti particles, BHA, or BHA hydrated with doxycycline solution (0.1 mg/ml) (BHATTC). Animals were sacrificed after 1 week, 5 weeks, or 6 months. Samples were analyzed using µCT and nondecalcified histology. Results: The materials used in each of the three groups allowed an optimal bone formation; bone quantities and densities were not statistically different between the three groups. At 6 months, more stable three-dimensional volume stability was found with Ti and BHATTC (p = .0033). At 5 weeks and 6 months, bone to material contact corroborating osteoconduction was significantly higher with BHA and BHATTC than with Ti (p < .0001). Conclusions and Clinical Implications: Even though the studied biomaterials displayed different architectures, they are relevant candidates for sinus lift bone augmentation prior to dental implants because they allow adequate three-dimensional stability and osteogenesis. However, to recommend the clinical use of Ti, both an observation on the drilling effects of Ti particles and clinical trials are needed. [less ▲]

Influence of Biomaterials in Alveolar Bone Regeneration and Preservation

Doctoral thesis (2011)

Dental implants are nowadays a reliable solution to replace missing teeth and have been widely documented. However, they require a minimal bone quantity (in height and thickness). But alveolar bone ... [more ▼]

Dental implants are nowadays a reliable solution to replace missing teeth and have been widely documented. However, they require a minimal bone quantity (in height and thickness). But alveolar bone defects are very frequent, for instance due to periodontitis, traumatism or acute dental infection. Moreover, a simple tooth extraction leads to significant bone resorption. Therefore, alveolar bone regeneration is often necessary in order to place implants and to restore the patient's dentition with implant-supported prosthesis. Even though alveolar bone reconstructions have been considered as traumatic, especially due to the need of a second surgical site for bone harvesting, techniques have evolved with the introduction of biomaterials. However, it is difficult to compare the influences of such biomaterials on osteogenesis and to elaborate on the advantages of one product over another. The overall objective of this thesis is to contribute to the understanding of the biological concept of alveolar bone regeneration, in particular sinus lift and socket preservation procedures. The influence of biomaterials on bone regeneration has been emphasized through preclinical and clinical studies. The number of commercially available biomaterials for bone regeneration is growing every day and some materials are not supported by strong scientific data in the literature. The first part of this thesis (Chapter 1) is dedicated to the characterization of several biomaterials often used in dentistry. The impact of their various characteristics on osteogenesis has been reviewed, from chemical aspect to micro- and macromorphology. Furthermore, a data sheet integrating the physico-chemical and morphological properties of each studied biomaterial has been developed as a tool for clinicians. Sinus floor elevation has often been considered as a bone graft. In 1996, a consensus conference on “sinus lift” took place and the procedure was qualified as “sinus bone-graft”. But new scientific evidence has shown that this qualification is not justified. Chapter 2 aims at understanding the physiology and the biological model of sub-sinusal bone augmentation by using either a simple blood clot, autogenous bone chips or biomaterials (BHA) as space fillers under the lifted sinusal membrane. If bone formation did occur with the 3 types of space fillers, the augmented volumes significantly dropped with the blood clot or the autogenous bone chips but remained stable with BHA. Therefore, a slowly resorbable biomaterial such as BHA might be suitable in sub-sinusal bone augmentation to prevent the re-expansion process. Understanding the biological concept of sinus lift procedures, several authors demonstrated the clinical efficacy of biomaterials when used alone in this specific model. Nevertheless, biomaterials known to be resorbable led to a lamellar bone architecture that might not be able to maintain the volume of the regenerated tissue over time. Moreover, many types of biomaterials are available and scientific evidence of short and long-term performance of newly introduced biomaterials is still poor. Chapter 3 aims at comparing the performances, in terms of bone formation, resorption rate and 3-D stability, of four calcium phosphate-based biomaterials often used for sub-sinusal bone augmentation, in a rabbit model. Particulated space-filling biomaterials seemed to be more efficient to promote osteogenesis compared to paste-like biomaterials. Highly resorbable biomaterials appeared to withstand intrasinusal pressure after a period of six months in rabbits. Non- or slowly resorbable biomaterials are of great interest in the dental field because the long-term stability of 3-D bone augmentation is a key factor for dental implant and aesthetic outcomes. Therefore, the mechanical and non-resorbable properties of titanium, known to be highly compatible in vivo and highly resistant to body fluid corrosion, are potential advantages for bone augmentation prior to dental implantation. Nevertheless, the use of titanium particles as space fillers in bone regeneration was weakly reported in the literature from a histological point of view. Thus, Chapter 4 compares the behavior and the effect of porous titanium particles versus the well-documented BHA. Even though both biomaterials allowed osteogenesis and adequate 3-D stability, the bone architecture, and more specifically the amount of bone-to-material contact (BMC), was significantly different. Inclusion of the particles in a carrier or in binding agents such as a collagen gel or fibers might be of interest in order to ease surgical handling. However, the possible influence of those collagen carriers on bone tissue responses remains poorly investigated. The objective of Chapter 5 was to investigate the effect of collagen at different stages of the osteogenesis process, still in the same rabbit model. The findings clearly showed the presence of inflammatory cells at an early stage of bone regeneration when collagenated xenogenic biomaterials were used compared to collagen-free xenogenic granules. Nevertheless, despite the transient inflammation, the final quantity of newly formed bone was similar in the various groups. The last two chapters of this thesis take some of the preclinical findings of the previous chapters to the clinical field. The objective of Chapter 6 was to assess the clinical outcome of a minimalized sub-sinusal bone augmentation procedure using only biomaterials, simultaneously with the placement of 102 non-submerged implants in 40 patients. Implant and prosthodontic survival rates as well as complications were evaluated after a follow-up period of 2 to 6 years. This clinical trial emphasized that, if the amount of remaining bone height is sufficient to ensure implant primary stability, their placement can be performed simultaneously with sinus lifting, even in a non-submerged fashion. This procedure reduces the number of surgeries and the time before prosthetic rehabilitation. The objective of Chapter 7 was to to develop a new method to objectively evaluate in humans the 3-D volume variation of alveolar socket preservation over time by means of computed tomography and 3-D image analysis. Short summary: Before placing dental implants, alveolar bone regeneration is often required due to bone defects caused by periodontitis, traumatism or even a simple tooth extraction. Bone augmentation surgical procedures have very much evolved thanks to a better understanding of biological processes and to the introduction of biomaterials. The overall objective of this thesis is to bring a contribution to the understanding of the biological concept of alveolar bone regeneration, and in particular sinus lift and socket preservation procedures. The influence of biomaterials on bone regeneration has been emphasized through preclinical and clinical studies. [less ▲]

Influence of space-filling materials in subantral bone augmentation: blood clot vs. autogenous bone chips vs. bovine hydroxyapatite

in Clinical Oral Implants Research (2011), 22(5), 538-545

Aim: The first objective of the present study was to compare the short- and long-term 3D volume stability of sub-sinusal bone regeneration in rabbits using different space fillers. The second objective ... [more ▼]

Aim: The first objective of the present study was to compare the short- and long-term 3D volume stability of sub-sinusal bone regeneration in rabbits using different space fillers. The second objective was to assess qualitatively and quantitatively the early bone formation process and long-term behavior of the regenerated bone. Materials and methods: Fifteen rabbits underwent a double sinus lift procedure using: blood clot (Clot), autogenous bone chips (Auto) and bovine hydroxyapatite (BHA). Animals were euthanized at 1 week, 5 weeks and 6 months. Samples were subjected to X-ray microtomography and histology. Variations in the volume of bone augmentations were calculated at different time points. Qualitative analysis was performed using 7 μm sections and quantitative histomorphometric analyses were carried out using scanning electron microscopy. Results: From baseline (100%) to 5 weeks, the augmented volumes declined to 17.3% (Clot), 57.6% (Auto) and 90.6% (BHA). After 6 months, only 19.4% (Clot) and 31.4% (Auto) of initial volumes were found, while it remained more stable in the BHA group (84%). At 1 week, an initial osteogenesis process could be observed in the three groups along the bone walls. At 5 weeks, despite a significant decline in the volume, newly formed bone density was higher with Clot and Auto than with BHA. At 6 months, bone densities were statistically similar in the three groups. However, after 6 months, the surface invaded by newly formed bone (regenerated area) was significantly higher when BHA was used as space filler. In the BHA group, the biomaterial area slightly decreased from 42.7% (1 week) to 40% (5 weeks) and 34.9% (6 months) and the density of the composite regenerated tissue (bone+BHA) reached >50% at 6 months. Conclusions and clinical implications: The three space fillers allowed bone formation to occur. Nevertheless, augmented volumes declined in the Clot and Auto groups, while they remained stable with BHA. A slowly resorbable biomaterial might be suitable in sub-sinusal bone augmentation for preventing the re-expansion process and for augmenting the density of the regenerated tissues. [less ▲]

One-step approach for implant placement and subantral bone regeneration using bovine hydroxyapatite: a 2- to 6-year follow-up study.

in International Journal of Oral & Maxillofacial Implants (2010)

Descriptive analysis of implant and prosthodontic survival rates with fixed implant-supported rehabilitations in the edentulous maxilla.

in Journal of Periodontology (2009), 80(8), 1220-30

BACKGROUND: This descriptive study reviewed the 1- to 15-year survival rates of fixed implant rehabilitations in the edentulous maxilla. METHODS: An electronic search was conducted, and cohort studies ... [more ▼]

BACKGROUND: This descriptive study reviewed the 1- to 15-year survival rates of fixed implant rehabilitations in the edentulous maxilla. METHODS: An electronic search was conducted, and cohort studies with 1- to 15-year follow-ups were identified by two independent reviewers. The implant and prosthodontic survival rates were reviewed at 1-, 3-, 5-, 10-, and 15-year endpoints. Descriptive analysis includes surface characteristics, bone-augmentation procedure, prosthetic design, and implant number and distribution along the edentulous maxilla. RESULTS: Thirty-three studies, including 1,320 patients and 8,376 implants, were selected for analysis. The overall calculated implant survival rates ranged from 94% (1 year) to 87.7% (15 years). The implant survival rates for rough-surface implants ranged from 97% (1 year) to 98% (15 years); machined implants showed survival rates of 92% to 87.7%; respectively. Implants placed in native bone had greater survival rates than those placed in augmented bone. The prosthodontic survival rate ranged from 98.2% at 1 year to 92.1% at the 10-year endpoint, and it was only influenced by the implant number and distribution. CONCLUSIONS: Implants with rough surfaces showed a statistically higher survival rate than machined implants at all intervals. Implants placed in augmented bone had a statistically lower survival rate, except for rough-surface implants, for which no statistical difference between augmented and non-augmented bone survival rates was found. Machined implants showed a stable survival rate only when placed in native bone. When machined implants were placed in augmented bone, the survival rate decreased significantly at each study endpoint. The prosthetic design, veneering material, and the number of prostheses per arch had no influence on the prosthodontic survival rate. Implant number and distribution along the edentulous maxilla seemed to influence the prosthodontic survival rate. [less ▲]

Sinus floor bone augmentation: implementation of the concept of sinus-lift]

in Revue Belge de Médecine Dentaire = Belgisch Tijdschrift voor Tandheelkunde (2009)

Sinus floor elevation is a technique allowing implant placement in the posterior edentulous maxilla when residual bone height is limited. This technique has evolved a lot since it has been first ... [more ▼]

Sinus floor elevation is a technique allowing implant placement in the posterior edentulous maxilla when residual bone height is limited. This technique has evolved a lot since it has been first introduced in the eighties. Nowadays, this approach is considered as predictable, simple and practicable under local anaesthesia. This present article aims at understanding clearly the biological phenomenon of “sinus- lift”. Moreover, the surgical protocol used at the University of Liège is considered didactically and reasoned according to the scientific literature. [less ▲]