Evidence insufficient to recommend routine antibiotics for joint replacement patients, experts say

Evidence insufficient to recommend routine antibiotics for joint replacement patients, experts say

Please read and save for future reference ! The latest recommendations for a commonly encountered clinical situation.

How Videogames Could Help Train the Next Generation of Robotic Surgeons

From Wired
I wonder when robotic surgery will be a reality in dentistry! OMFS will most probably be the place it will make it's first impact. In the meantime I'm going to get started on my video games!


How Videogames Could Help Train the Next Generation of Robotic Surgeons: Doling out death in the virtual world of first-person-shooter games might help the next generation of surgeons save lives in the real world. A new study used simulators to compare the robotic surgery skills of med school residents against college and high school students who spend a lot of their time playing video games -- and the video gamers won.

Periodontist Group Develops Diabetes Educational Material

Periodontist Group Develops Diabetes Educational Material: In honor of November, American Diabetes Month, the New Jersey Society of Periodontists developed this great brochure that can help your patients understand the diabetes/periodontal disease connection. If you have a blog or use social media for your dental practice, we recommend sharing these images so your patients can learn more about how their oral [...]

A very nice and informational brochure. Print it out for your patients or put it up on your wall. 

Surgical Rehearsal Platform Makes Virtual Operations Possible (Interview)

Surgical Rehearsal Platform Makes Virtual Operations Possible (Interview):
Medicine is continuously learning from other fields, perhaps the best example being aviation. It is from aviation that we gained the benefits of checklists, integrated ICUs and ORs, and – most recently – simulators. The first computer-based flight simulators came out 50 years ago and only now are we getting up to speed in terms of developing systems that enable surgeons to rehearse operations in advance.
This past June Medgadget met up with the Surgical Theater team at The White House and discussed how they are turning this vision into a reality – or, rather, the other way around. Their flagship product, the Selman Surgical Rehearsal Platform (SRP), allows surgeons to “pre-live the future” by practicing procedures on their actual patients’ anatomies using pre-operative MRI and CT images. We heard from them recently because the SRP has reached a few milestones in the past six months, including its first purchase by University Hospitals (UH) Case Medical Center in Cleveland and submission for FDA approval.
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Vertical Augmentation of the Posterior Mandible

Vertical augmentation of the posterior mandible remains challenging. A variety of approaches have been tried. Among them are:

• Short Implants
• Vertical augmentation using block grafts (autogenous,alloplastic as well as xenogenic).
• Vertical augmentation using tenting screws, and a mixture of autograft and bovine bone mineral covered with a titanium reinforced PTFE membrane barrier.This is quite popular.
• Vertical augmentation as above but using the implants themselves as tenting screws.
• Tilted implants where feasible.
• Transverse placement to avoid the IAN.
• Nerve repositioning/relocation.
• Subperiosteal implants if the resorption is down to basal bone. Not commonly used currently due to the high rate of failure and complications, technique sensitivity and lack of validating studies.

Another technique which does not enjoy the popularity it deserves is the interpositional graft. As far as techniques go I would rate it as moderately difficult but the results are phenomenal and complications are few. This has also been popularised by Ole Jensen as the "smile osteotomy" in his book The Osteoperiosteal Flap

Here is an illustration from the book that illustrates the procedure

The case presented below differs in some respects.

• The interpositional graft used was a FDBA Bone Block from Tata Bone Bank in Mumbai not autogenous bone or particulate graft material..
• No bone plates were used to stabilise the fragments. In some cases this may be necessary.

The "smile" osteotomy

Mobilising the the fragment vertically. Note that the coronal fragment is still pedicled to the lingual mucosa. The incision in the soft tissue is vestibular rather than crestal. One can use a bur, peizosurgery saw or oscillating saw for this cut..One can easily create a gap of 5 to 6mm or more using this technique. 

Maintaining the gap with a graft: Here we have used a block of FDBA from the Tata Tissue Bank in Mumbai. Alternatively one can use autograft harvested from the chin or ramus , or practically any kind of allograft or xenograft by itself or mixed with autograft. In case of particulate autograft it may be necessary to stabilise the coronal fragment with plates and screws. This may be needed even in case of block grafts if the fragments do not maintain position. 

Three or four months later the graft is on its way to being replaced by the body's own bone and one can see the margins of the osteotomy have been bridged over. The increase in vertical height is evident.

Implants have been placed .

A Classic "Royally" treated

What do you think of this "bed of Nails"?

Christensen pins implant makers !

Upfront as always Gordon Christensen makes a strong point. Follow the link to this article in drbicuspid.com
http://www.drbicuspid.com/index.aspx?sec=sup&sub=rst&pag=dis&itemId=311794&wf=1380

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Is Bruxism a Risk Factor for Dental Implants? A Systematic Review of the Literature

I haven't read the original study but the abstract seems interesting. The authors attempt to answer a question that we all have asked ourselves at some time or another. But we still don't have a useful classification system for Bruxism or Parafunction that allows us to categorise patients in some clinically relevant fashion.....
If someone has access to the original paper I would appreciate if you could mail it to me !
Is Bruxism a Risk Factor for Dental Implants? A Systematic Review of the Literature:

Abstract

Purpose

To systematically review the literature on the role of bruxism as a risk factor for the different complications on dental implant-supported rehabilitations.

Material and Methods

A systematic search in the National Library of Medicine's Medline Database was performed to identify all peer-reviewed papers in the English literature assessing the role of bruxism, as diagnosed with any other diagnostic approach (i.e., clinical assessment, questionnaires, interviews, polysomnography, and electromyography), as a risk factor for biological (i.e., implant failure, implant mobility, and marginal bone loss) or mechanical (i.e., complications or failures of either prefabricated components or laboratory-fabricated suprastructures) complications on dental implant-supported rehabilitations. The selected articles were reviewed according to a structured summary of the articles in relation to four main issues, viz., “P” – patients/problem/population, “I” – intervention, “C” – comparison, and “O” – outcome.

Results

A total of 21 papers were included in the review and split into those assessing biological complications (n = 14) and those reporting mechanical complications (n = 7). In general, the specificity of the literature for bruxism diagnosis and for the study of the bruxism's effects on dental implants was low. From a biological viewpoint, bruxism was not related with implant failures in six papers, while results from the remaining eight studies did not allow drawing conclusions. As for mechanical complications, four of the seven studies yielded a positive relationship with bruxism.

Conclusions

Bruxism is unlikely to be a risk factor for biological complications around dental implants, while there are some suggestions that it may be a risk factor for mechanical complications.

Something to think about !

ADA News 2012 Conference:

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Must See Video!

A very dramatic representation of the difference in strength between a PFM and a ful contour zirconia crown. Worth watching !

Bone-to-implant contact after maxillary sinus floor augmentation with Bio-Oss and autogenous bone in different ratios in mini pigs

Bone-to-implant contact after maxillary sinus floor augmentation with Bio-Oss and autogenous bone in different ratios in mini pigs:

Abstract

Objectives

The objective was to test the hypotheses: (i) no differences in bone-to-implant contact formation, and (ii) no differences between the use of autogenous mandibular or iliac bone grafts, when autogenous bone, Bio-Oss mixed with autogenous bone, or Bio-Oss is used as graft for the maxillary sinus floor augmentation.

Material and methods

Bilateral sinus floor augmentation was performed in 40 mini pigs with: (A) 100% autogenous bone, (B) 75% autogenous bone and 25% Bio-Oss, (C) 50% autogenous bone and 50% Bio-Oss, (D) 25% autogenous bone and 75% Bio-Oss, or (E) 100% Bio-Oss. Autogenous bone was harvested from the iliac crest or the mandible and the graft composition was selected at random and placed concomitant with the implant placement. The animals were euthanized 12 weeks after surgery. Bone-to-implant contact was estimated by stereological methods and summarized as median percentage with 95% confidence interval (CI). Bone-to-implant contact formation was evaluated by fluorochrome labelling and assessed by median odds ratios (OR) with 95% (CI).

Results

Median bone-to-implant contact was: (A) 42.9% (95% CI: 32.1–54.5%), (B) 37.8% (95% CI: 27.1–49.9%), (C) 43.9% (95% CI: 32.6–55.9%), (D) 30.2% (95% CI: 21.6–40.3%), and (E) 13.9% (95% CI: 11.4–16.9%). Bone-to-implant contact was significantly higher for A, B, C, D as compared to E (P < 0.0001). Bone-to-implant contact was not significantly influenced by the ratio of Bio-Oss and autogenous bone (P = 0.19) or the origin of the autogenous bone (P = 0.72). Fluorochrome labelling revealed extensive variation in bone-to-implant contact formation over time. The labelling at weeks 2–3 was significantly increased with A compared to E (OR = 8.1 CI: 5.0–13.1, P < 0.0001), whereas E showed a significantly increased labelling at weeks 8–9 compared to A (OR = 0.5 CI: 0.3–0.7, P = 0.0028).

Conclusions

The hypothesis of no differences in bone-to-implant contact between the various treatment modalities was rejected since the bone-to-implant contact was significantly increased with autogenous bone or Bio-Oss mixed with autogenous bone as compared to Bio-Oss. Early bone-to-implant contact formation was more advanced with autogenous bone. No differences between the use of mandibular or iliac bone grafts were observed since the bone-to-implant contact was not significantly influenced by the origin of the bone graft.

Significance of keratinized mucosa around dental implants: a prospective comparative study

Significance of keratinized mucosa around dental implants: a prospective comparative study:

Abstract

Objective

The aim of this investigation was to evaluate the significance of keratinized mucosa (KM) around dental implants both clinically and biochemically for 12 months.

Material and methods

Fifteen edentulous patients treated with implant-retained overdentures in edentulous mandible (four implants per patient). Based on the presence of keratinized mucosa on the buccal surfaces, implants were divided into two groups: Implants having minimal 2 mm of KM on their buccal surfaces and implants having no KM on their buccal surfaces. Thirty-six implants were included in the evaluations; 19 implants in 15 patients had minimal 2 mm of KM on their buccal surfaces and 17 implants in 15 patients had no KM on their buccal surfaces. Clinical measurements of Plaque Index, Gingival Index, probing depths, and Bleeding on Probing were performed and peri-implant crevicular fluid (PICF) were collected immediately before loading (baseline) and at 6th, 12th months after loading. Interleukin-1 beta (IL-1 β) and tumor necrosis factor-alpha (TNF-α) have been assessed in the crevicular fluid. Results were analyzed by repeated-measures of variance (ANOVA) and Wilcoxon signed rank tests.

Results

After 12 months of evaluation the results of ANOVA showed that implants with KM had lower levels of TNF-α total amounts than implants without KM (P < 0.05). Additionally, TNF-α total amounts were significantly higher at 12^th month compared to baseline for implants without KM (P < 0.05). Plaque index and Gingival index values were also found significantly higher for implants without KM (P < 0.05). For IL-1 β and PICF volume levels the differences between the implant groups were non significant, whereas the differences between the periods were significant. (P < 0.05) Additionally, both of the groups had higher levels of PII and BoP scores when compared to baseline (P < 0.05).

Conclusions

The results of this study showed that an adequate band of keratinized mucosa was related with less plaque accumulation and mucosal inflammation as well as pro-inflammatuar mediators, suggesting that it may be critical especially for plaque control and plaque associated mucosal lesions around dental implants.

These Silently Screaming Dental Mannequins Are What Nightmares Are Made Of [WTFriday]

These Silently Screaming Dental Mannequins Are What Nightmares Are Made Of [WTFriday]:

These synthetic heads don't need to be anywhere near the Uncanny Valley to be terrifying. Our friends at Oobject have assembled 12 of the creepiest prosthetic mouths in dentistry. More »

Graphene Nanosensor Monitors Bacteria in Your Mouth

Graphene Nanosensor Monitors Bacteria in Your Mouth:
A team of scientists from Tufts University and Princeton University have developed a wireless bacteria detection technology which can be interfaced with a number of surfaces, including biological substrates, such as the enamel of a tooth.  The researchers used graphene to achieve a very high degree of sensitivity. By printing the graphene onto water soluble silk, the sensor could then be easily transferred to biological surfaces. A patterned resonator coil design on the printed sensor acts as a passive antenna to enable power and wireless communication with the sensor.
Most recently, the researchers have demonstrated their sensor by attaching it to a tooth for monitoring of respiration and bacteria detection in saliva.Their findings have  been reported in the March 27 online edition of Nature Communications.
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New Gel May Mean No More Dental Anesthesia Shots - Science News - redOrbit

This seems exciting. It would definitelymake treatment more acceptable to many of our patients !

New Gel May Mean No More Dental Anesthesia Shots - Science News - redOrbit:

Anesthetic gel made from a rare plant found deep in the Peruvian rainforest has been found to be so potent that it could potentially replace the uncomfortable anesthetic injections used prior to dental procedures — and provide a natural remedy for aching teeth, scientists say.

The remarkable painkilling properties of the Acmella oleracea plant, commonly referred to as Spilanthes Extract, have been used for centuries if not millennia by Incas to treat toothache, ulcers, abscesses and to even clean teeth.

Indigenous tribes revealed the secrets of the plant to Cambridge University researcher Dr. Françoise Barbira Freedman, who has spent more than 30 years visiting and living with the Keshwa Lamas tribe of Peru. Freedman said the plant could literally transform western dental practice.

Freedman became the first westerner to be accepted into the secretive society in 1975. During one of her trips to the rainforest, she suffered severe pain in her wisdom teeth. She was given the remedy by the tribe‘s medicine men and the pain subsided “immediately,” she said. more

Source: redOrbit (http://s.tt/17lS9)

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Membrane Perforation in Sinus Floor Elevation – Piezoelectric Device versus Conventional Rotary Instruments for Osteotomy: An Experimental Study

It seems NOTHING , nothing is a substitute for knowledge, experience and expertise !

A piezosurgery device is a very useful adjunct for doing sinus floor elevations. But it is not a magic wand that will make membrane perforations go away !

Membrane Perforation in Sinus Floor Elevation – Piezoelectric Device versus Conventional Rotary Instruments for Osteotomy: An Experimental Study:

ABSTRACT

Purpose: Sinus membrane perforation is the most common intraoperative complication of maxillary sinus floor elevation (MSFE) procedures and frequently causes postoperative problems. Piezoelectric devices have been claimed to reduce the frequency of membrane perforations although no clear evidence supports this view.

Materials and Methods: Ten surgeons with different expertise levels performed 80 MSFEs in selected lamb heads, with rotary and piezoelectric instruments following standard protocols. After the procedures, specimens were coded and perforations or tears determined through a microscope.

Results: No significant differences in terms of thickness either of the sinus lateral wall (x_i-x_j = 73.2; 95% confidence interval [CI] = 45.3–191.8) or the membrane (x_i-x_j = 24.2; 95% CI = −29.4 to 77.9) were identified between the specimens allocated to each group. Nine membrane perforations (11.2%) occurred during the study, all within the lower expertise group. Membrane elevation by hand instruments caused five perforations (40%) in the rotary instrument group and one in the piezoelectric group. Expert surgeons produced no membrane perforations, the size of the antrostomy that was smaller in the piezoelectric group being the only significant difference between the rotary and piezoelectric groups.

Conclusions: The use of piezoelectric material for MSFE reduces the frequency of membrane perforation among surgeons with a limited experience.

Soft Tissue Preservation and Pink Aesthetics around Single Immediate Implant Restorations: A 1-Year Prospective Study

As one can see from the abstract below , even when the biotype is thick and buccal bone is intact achieving esthetic success with immediate implant placement in the esthetic zone is fraught with uncertainty. The protocol suggested by Buser and Belser for early placement after soft tissue healing is probably a safer protocol for most of us in clinical practice where predictability is key.

Soft Tissue Preservation and Pink Aesthetics around Single Immediate Implant Restorations: A 1-Year Prospective Study:

ABSTRACT

Purpose: (1) To document soft tissue aspects using a specific protocol for immediate implant treatment (IIT) following single-tooth removal; (2) to evaluate whether this protocol allows preservation of pink aesthetics as objectively assessed.

Materials and Methods: Patients with a thick gingival biotype and intact buccal bone wall upon extraction of a single tooth in the aesthetic zone (15–25) were consecutively treated. The protocol included flapless extraction and implant surgery, socket grafting, immediate nonocclusal loading with a screw-retained provisional crown, and replacement by a permanent crown 6 months thereafter. The outcome was assessed after 3, 6, and 12 months. Cases demonstrating major alveolar process remodeling and/or advanced midfacial recession (>1 mm) at 3 months were additionally treated with a connective tissue graft (CTG). The emergence profile of the provisional crown was replicated for all permanent crowns.

Results: Twenty-two patients (12 men, 10 women; mean age 50) were treated after tooth extraction for nonperiodontal reasons using a novel bone condensing implant with variable-thread design, conical connection, and platform switch (NobelActive®, Nobel Biocare, Göteborg, Sweden). One implant failed and mean marginal bone loss was 0.1 mm (p = .059). Temporary mesial papilla reduction occurred, whereas distal papilla reduction was permanent (mean 0.5 mm; p = .001). At 3 months, five cases demonstrated major alveolar process remodeling and two advanced midfacial recession. Hence, slight initial decline in the pink esthetic score (PES) (p = .053) was observed. CTG resulted in a steady improvement of the PES after 3 months (p ≤ .037). At 12 months, pink aesthetics (mean PES 12.15) was comparable to the preoperative status (mean PES 11.86; p = .293). Distal papillae had significantly deteriorated (p = .020) in this time span, whereas midfacial contour had significantly improved (p = .005).

Conclusions: Preservation of pink aesthetics is possible following IIT. However, to achieve that, CTG may be necessary in about one-third of the patients. Major alveolar process remodeling is the main reason for additional treatment.

A Novel Use for Biphosphonates !

A Bioactive Nanolayer for Orthopedic and Dental Implants

(Nanowerk News) AddBIO AB, a subsidiary of Accelerator Nordic AB, has developed Zolidd®, a proprietary bioactive nanolayer for orthopedic and dental implants that releases bisphosphonate, a bone strengthening drug. A randomized clinical trial, conducted at Linköping University Hospital, Sweden, shows that dental implants with a bisphosphonate nanolayer have improved stability (see paper in Bone:"A bisphosphonate-coating improves the fixation of metal implants in human bone. A randomized trial of dental implants").

Millions of people worldwide have dental implants, i.e. screws inserted to support artificial teeth. The first time after surgery, the implant is often not stable enough to enable chewing. It may take several months for the bone around the implant to heal and become strong enough for the patient to regain normal chewing function.

"The study shows that local bisphosphonate improves implant stability, meaning that the time until normal chewing function could be shortened, thus reducing the suffering for the patient", says Professor Per Aspenberg, Linköping University Hospital, co-founder of AddBIO.

Zolidd is the first application from a platform technology designed for local release of drugs from medical implants, developed by Professors Per Aspenberg and Penti Tengvall, Linköping University. A nanometer-thin protein layer is attached to the metal surface and a bisphosphonate is attached to the protein. When the bisphosphonate is released, a local effect is obtained, which improves implant stability. In the present study, a Zolidd prototype was used to release bisphosphonate in this way.

Sixteen patients each received two implants, one with bisphosphonate and one without. After six months, the bisphosphonate treated implant showed improved stability in 15 out of 16 patients. On x-rays, the treated implants showed positive effects already after two months. No complications occurred.

"This is an important study. With these results, we are now ready to take the next step in commercializing Zolidd", says Dr. Trine Vikinge, CEO AddBIO.

Source: AddBIO (press release)

Dental CR Reader Featuring Tablet Support

Dental CR Reader Featuring Tablet Support:

3DISC Imaging inc., Dulles, VA, a manufacturer of digital imaging products, has developed a compact imaging device that provides reading of reusable dental imaging plates. The FireCR Dental Reader features a tablet computer to immediately view and share imaging results at the chair side and features touch screen software that provides dentists with immediate access to the history of the patient’s dental images.

The reader is DICOM 3.0 compatible with existing systems and uses low-cost, reusable imaging plates in a variety of sizes, including bite-wing and intraoral dental imaging plates.

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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:

Abstract

Introduction

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%.

Results

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.

Discussion

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:

Abstract

Objective

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.

Results

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.

Conclusion

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:

Abstract

Objectives

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.

Results

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.

Conclusions

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:

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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Guided bone regeneration using collagen membranes for sinus augmentation

http://www.bjoms.com/article/PIIS026643561000330X/abstract?rss=yes