Maxillary sinus floor augmentation with Bio-Oss or Bio-Oss mixed with autogenous bone as graft in animals: a systematic review

Abstract

The objective of the present systematic review was to test the hypothesis of no differences between the use of Bio-Oss or Bio-Oss mixed with autogenous bone as graft for maxillary sinus floor augmentation (MSFA) applying the lateral window technique, as evaluated in animals. A MEDLINE (PubMed), Embase, and Cochrane Library search in combination with a hand-search of relevant journals was conducted by including animal studies published in English from 1 January 1990 to 1 June 2010. The search provided 879 titles and 14 studies fulfilled the inclusion criteria. The volumetric stability of the graft improved significantly with increased proportion of Bio-Oss. Bone regeneration, bone-to-implant contact (BIC), biomechanical implant test values, and biodegradation of Bio-Oss after MSFA with Bio-Oss or Bio-Oss mixed with autogenous bone have never been compared within the same study in animals. Thus, the hypothesis of no differences between the use of Bio-Oss and Bio-Oss mixed with autogenous bone as graft for MSFA could neither be confirmed nor rejected based on existing animal studies.

Maxillary sinus floor augmentation (MSFA) using the lateral window technique is the most commonly applied method to increase the alveolar bone height of the posterior part of the maxilla, and high prosthesis and implant survival rates have been reported in several systematic reviews .

Autogenous bone is generally the preferred graft material , but the use of autogenous bone is associated with risk of donor site morbidity and unpredictable graft resorption so, increasingly, various bone substitutes are being used.

A deproteinized bone substitute of bovine origin (Bio-Oss, Geistlich Pharma, Wolhusen, Switzerland) is frequently used for MSFA, either alone or in combination with autogenous bone . The anorganic bone matrix of Bio-Oss appears to have a microporous structure similar to human cancellous bone , but the outcome of MSFA with Bio-Oss or Bio-Oss mixed with autogenous bone in animal studies has not previously been assessed in a systematic review.

The objective of the present systematic review was to test the hypothesis of no differences in the use of Bio-Oss or Bio-Oss mixed with autogenous bone as graft for MSFA applying the lateral window technique, as evaluated in animal studies.

Materials and methods

Animal studies assessing MSFA with Bio-Oss or Bio-Oss mixed with autogenous bone using the lateral window technique were evaluated. No animal species restrictions were applied.

The outcome measures included: bone regeneration; bone-to-implant contact (BIC); biomechanical implant test values; biodegradation of Bio-Oss; and volumetric stability of graft.

The search strategy used for identification of studies is summarized in Fig. 1 . A MEDLINE (PubMed), Embase, and Cochrane Library search was conducted by including studies published in English from 1 January 1990 to 1 June 2010. The search strategy utilized a combination of controlled vocabulary (MeSH) and free text terms: (1) exp Maxillary sinus; (2) exp Bone regeneration; (3) ‘Bio-Oss’; 1 AND 2 OR 3.

Fig. 1
Search strategy for identification of studies.

The search was supplemented by a thorough hand-search page by page of relevant journals ( Fig. 1 ). The manual search also included the bibliographies of all articles selected for full-text screening as well as previously published reviews relevant for the present systematic review. The search was performed by one reviewer (TJ).

The titles of the identified reports were screened initially ( Fig. 1 ). The abstract was assessed when the title indicated that the study fulfilled the inclusion criteria. Full-text analysis was carried out when the abstract was unavailable or when the abstract indicated that the inclusion criteria were fulfilled. The study selection was performed by one reviewer (TJ).

Animal studies assessing the outcome of MSFA with Bio-Oss or Bio-Oss mixed with autogenous bone as graft were included by addressing the previously described outcome measures. The review focused on studies using the lateral window technique for MSFA. Studies comparing Bio-Oss with other bone substitutes were included, if the outcome measures could be identified for Bio-Oss or Bio-Oss mixed with autogenous bone.

Animal studies assessing the outcome of MSFA with Bio-Oss mixed with other bone substitutes, bone morphogenetic proteins, or platelet-rich plasma were excluded. Also studies with insufficient description of the number of MSFA procedures performed, number of animals included, and number of inserted implants were excluded. Studies with insufficient description of the length of the observation period were excluded.

Data were extracted by one reviewer (TJ) according to the data-collection form ensuring systematic recording of the outcome measures. Relevant characteristics of the animal model used and length of the observation period were recorded. The studies included revealed considerable variations in study design, such as length of observation period, species, ratio of Bio-Oss and autogenous bone, type of implant, immediate or delayed implant placement, loading protocol, presence or absence of a barrier membrane, and outcome measures, therefore, meta-analyses were not applicable.

The search result is outlined in Fig. 1 . 879 titles were identified, and 121 abstracts were reviewed. Full-text analysis included 22 articles and 14 studies were finally included . No additional reports were included as the result of hand-searching. Only one comparative study was identified focusing on the volumetric stability of the graft . The main results are described below and summarized in Tables 1–3 .

Table 1
Comparative studies.
Animal Material and methods Length of observation period Results Ref.
Histology and radiography Other results
32 minipigs 32 sinuses with iliac bone and Bio-Oss in different ratios
32 Brånemark implants simultaneously
12 weeks Resorption of graft Volumetric stability of graft improved significantly with increased proportion of Bio-Oss
Volumetric stability not related to origin of autogenous bone graft, i.e. bone from either mandible or iliac crest
J ensen et al.
Graft Iliac bone Mandible bone
Bone 75% and Bio-Oss 25% 40% 35%
32 sinuses with mandibular bone and Bio-Oss in different ratios
32 Brånemark implants simultaneously
Bone 50% and Bio-Oss 50% 22% 25%
Bone 25% and Bio-Oss 75% 13% 19%
Bio-Oss 100% 6% 6%

All group values referred to are expressed as mean values.

Table 2
Supplementary studies with Bio-Oss.

All group values referred to are expressed as mean values. Abbreviations : BIC: bone-to-implant contact; NR: not reported.
a Amounts of new bone formation and remaining Bio-Oss were evaluated medially, laterally, and apically around the implants.

Table 3
Supplementary studies with Bio-Oss mixed with autogenous bone.
Animal Material and methods Length of observation period Results Ref.
Histology and radiography Other results
5 minipigs 5 sinuses with 50% iliac bone and 50% Bio-Oss
5 ITI implants simultaneously
6 weeks BIC: 17%
Height of newly formed bone: 5.7 mm
Newly mineralized bone: 52%
Proportion of newly formed bone declined substantially with increasing distance from host bone R oldán et al.

All group values referred to are expressed as mean values. Abbreviation : BIC: bone-to-implant contact.

Results

For each outcome measure the results of comparative studies of Bio-Oss as opposed to Bio-Oss mixed with autogenous bone are presented first ( Table 1 ). This is followed by results of supplementary studies including only one of the two treatment modalities ( Tables 2 and 3 ).

Bone regeneration

No comparative studies were identified.

In supplementary studies, the proportion of newly formed mineralized bone varied between 20% and 70% after 4–18 months when MSFA involved Bio-Oss , and bone regeneration seemed to increase during a 1–12-week healing period . The proportion of newly formed bone declined substantially with increased distance from the host bone . Bio-Oss particles within the central part of the augmented region were embedded entirely in connective tissue, whilst Bio-Oss particles adjacent to the host bone were mainly surrounded by newly formed bone. The proportion of newly formed bone was 52% after 6 weeks, when a mixture of 50% Bio-Oss and 50% iliac bone was used .

In summary, bone regeneration after MSFA with Bio-Oss or Bio-Oss mixed with autogenous bone has never been compared within the same study.

Bone-to-implant contact

No comparative studies were identified.

In supplementary studies, when Bio-Oss was used, BIC varied between 0.4% after 3 weeks and 58% after 180 days for simultaneously inserted implants . Implants inserted in a delayed surgical procedure demonstrated 47–57% BIC after a healing period of 4–15 months . BIC increased with the length of the observation period , but a healing period of more than 8 months seemed not to improve BIC substantially . BIC was always higher in the residual bone than in the augmented bone . BIC after using a mixture of 50% Bio-Oss and 50% iliac bone was 17% after 6 weeks for simultaneously inserted implants .

In summary, BIC after MSFA with Bio-Oss or Bio-Oss mixed with autogenous bone has never been compared within the same study.

Biomechanical implant test values

No comparative studies were identified. In supplementary studies, implant pull-out strength increased significantly from 325 N after 12 weeks to 522 N after 26 weeks when Bio-Oss was used . In summary, biomechanical implant test values after MSFA with Bio-Oss or Bio-Oss mixed with autogenous bone have never been compared within the same study.

Biodegradation of Bio-Oss

No comparative studies were identified.

In supplementary studies, no, or limited, biodegradation of the Bio-Oss particles was reported up to 15 months after MSFA with Bio-Oss , whilst pronounced biodegradation with only a few remaining Bio-Oss particles after 6 months was reported in one study . The above-mentioned studies included histologic evaluation of the presence or absence of osteoclast-like cells at specific time-points . No study included quantitation over time. No significant differences in the proportion of remaining Bio-Oss particles were revealed after 7.5 months and 1.5 year .

In summary, biodegradation of Bio-Oss after MSFA with Bio-Oss or Bio-Oss mixed with autogenous bone has never been evaluated within the same study.

Volumetric stability of graft

In comparative studies, the volumetric stability of the graft with Bio-Oss, or different ratios of Bio-Oss and autogenous bone, has been assessed after 12 weeks in minipigs using unbiased three-dimensional quantitation of computed tomography Images . The volumetric stability of the graft was significantly influenced by the ratio of Bio-Oss and autogenous bone, but not by the origin of the autogenous bone graft, i.e. bone from either the mandible or the iliac crest.

In supplementary studies, when MSFA involved the use of Bio-Oss, two-dimensional quantitation of histologic sections demonstrated a 15% and 17% volumetric reduction after 90 and 180 days, respectively .

In summary, the volumetric stability of the graft after MSFA improved significantly with increased proportion of Bio-Oss in the graft.

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Jan 26, 2018 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Maxillary sinus floor augmentation with Bio-Oss or Bio-Oss mixed with autogenous bone as graft in animals: a systematic review
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