Sunday, January 8, 2012

A 6-month histological analysis on maxillary sinus augmentation with and without use of collagen membranes over the osteotomy window: randomized clinical trial

Wallace and others from the NYU Group have argued on the basis of their own clinical experience and based on their and other meta analyses that covering the sinus window with a collagen membrane makes a significant difference both to the quality of the regenerated bone as well in turn to the overall survival of dental implants placed into the sinus. Others such as Fuggazotto have argued to the contrary.
The current study inspite of its small sample size (n=18) seems to suggest that there was no difference in the amount of vital bone formed in both groups but that use of a membrane resulted in better corticalisation of the osteotomy window.
In the Indian scenario considering the cost that a collagen membrane adds to what is an already expensive procedure we might want to wait for more conclusive evidence !

A 6-month histological analysis on maxillary sinus augmentation with and without use of collagen membranes over the osteotomy window: randomized clinical trial:



Over the years, several modifications have been made to the sinus augmentation technique and to the materials used. However, there is still controversy about the need for using a barrier concurrently with a graft in sinus augmentation procedures. On this basis, the aim of this randomized clinical study was to investigate the effect of resorbable collagen membrane over the osteotomy window on maxillary sinus augmentation healing.

Materials and methods

Patients who required maxillary sinus augmentation were evaluated and selected to enter the study. After maxillary sinus grafting, each patient was randomly assigned to control (membrane over the osteotomy window) or test (no membrane) group. After 6 months, one bone biopsy was harvested from the lateral window and sent to the histology laboratory. The Mann–Whitney nonparametric test was used for comparing the two groups. P-value was set at 5%.


Eighteen patients entered the study and were randomly allocated in control (nine patients) or test group (nine patients). The histomorphometric measurements revealed that newly formed bone was 30.7% ± 15.5% of the total volume from the membrane group (control). The average percentage of connective tissue was 50.6% ± 18.7% and residual graft percentage was 18.4% ± 20.3%. On the other hand, data regarding the nonmembrane group (test) showed that the percentage of newly formed bone was 28.1% ± 19.4%. The mean percentage of connective tissues was 59.3% ± 15.4% and 12.6% ± 12.4% for the residual graft particles. No significant difference was detected in the histomorphometrical evaluation between the two groups.


Our results showed that, compared with sites not covered, the use of the membrane did not substantially increase the amount of vital bone over a period of 6 months. On the other hand, the use of membrane seems to reduce the proliferation of the connective tissue and the graft re-absorption rate. It is plausible that blood supply of maxillary sinus can play a role in such a result. Further studies are needed to explore whether the use of membrane could really be advantageous for the sinus augmentation procedure and to evaluate what influence this method can have on the amount and quality of reconstructed bone.

Histologic and histomorphometric evaluation of a synthetic bone substitute for maxillary sinus grafting in humans

Many of us here in India use Biphasic Ceramics such a Ossifi or Biograft for our sinus lifts. All there is an extensive orthopedic literature on the use of these materials ,studies describing their use in oral applications has been slow in coming. This study helps increase our confidence in the use of these products. It's important to note however that one needs to wait atleast 9 to 12 months for graft maturation before one can proceed to implant placement in moderate sized sinuses . In extremely large , heavily pneumatised sinuses using a mixture of alloplast and autograft will shorten healing times.

Histologic and histomorphometric evaluation of a synthetic bone substitute for maxillary sinus grafting in humans:



The present study investigated the efficacy of a biphasic calcium phosphate as a bone grafting material for maxillary sinus augmentation in humans.

Materials and methods

Half of the thirty patients selected for sinus augmentation were grafted with biphasic calcium phosphate, whereas the other half were grafted with autogenous bone chips harvested intraorally. After 9 months of healing, bone cores were retrieved from implant sites for histologic and histomorphometric evaluation.


The areas augmented with autogenous bone chips showed newly formed bone with a pattern very similar to that of the native area. Histomorphometry demonstrated that the amount of newly formed bone in the autogenous bone group was significantly greater than in the biphasic calcium phosphate group (P < 0.05). In the biphasic calcium phosphate group, less bone formation was observed in the area further away from native bone interface than in the area closer to native bone interface (P < 0.05), whereas no significant differences were observed between both areas in the autogenous group. In both groups, the implant survival rate was 100% with a minimum 1-year follow-up.


The data presented in this work confirm the osteoconductive properties of biphasic calcium phosphate, as well as its use in association with maxillary sinus floor augmentation procedures with successful outcomes.

Histomorphometric and immunohistochemical analysis of human maxillary sinus-floor augmentation using porous β-tricalcium phosphate for dental implant treatment

Interesting to note that there was a gradient of of positive staining cells. The greatest density was close to the native bone and the least was at the apical extensions of the graft.

Histomorphometric and immunohistochemical analysis of human maxillary sinus-floor augmentation using porous β-tricalcium phosphate for dental implant treatment:



This study utilized the constitution and expression of Runx2/Cbfa1 to conduct 6-month-post-operation histomorphometrical and histochemical analysis of osteocalcin in bone regeneration following sinus-floor augmentation procedures using β-tricalcium phosphate (β-TCP) and autogenous cortical bone.

Material and methods

Thirteen sinuses of nine patients were treated with sinus-floor augmentation using 50% β-TCP and 50% autogenous cancellous bone harvested from the ramus of the mandible. Biopsies of augmented sinuses were taken at 6 months for histomorphometric and immunohistochemical measurements.


Runx2/Cbfa1- and osteocalcin-positive cells were found around TCP particles and on the bone surface. Approximately 60% of cells found around TCP particles stained positive for Runx2/Cbfa1. Fewer cells stained positive for osteocalcin. These positive cells decreased apically with increasing vertical distance from the maxillary bone surface. Histomorphometric analysis showed that the augmented site close to residual bone and periosteum contained approximately 42% bony tissue and 42% soft connective tissue, and the remaining 16% consisted of TCP particles. On the other hand, the augmented bone far from residual bone and periosteum contained 35% bony tissue and 50% soft connective tissue.


Our data suggest that TCP particles attract osteoprogenitor cells that migrate into the interconnecting micropores of the bone-substitute material by 6 months. The augmented site close to residual bone contained a higher proportion of bony tissue and a lower proportion of soft connective tissue than did the augmented site far from residual bone.

Novel Glass Ceramic Puts a Bang in Your Bite

A new development in ceramics !

Novel Glass Ceramic Puts a Bang in Your Bite: 39481_web

Chemists from the Otto-Schott-Institute for Glass Chemistry at Jena University in Germany have produced a new kind of glass ceramic with a nanocrystalline structure. The material has high strength characteristics and optical properties which make it ideal for use in dental applications.

The ceramic material comprises magnesium, aluminum and silicon dioxide, a combination known for its high strength properties. So far the new material has demonstrated a strength five times greater than comparable denture ceramics. By making the ceramic optically similar to natural teeth the researchers have overcome the major barrier for use of the material in dental applications.

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