Single and double density biopolymer foams, composite biopolymer foams including both single and double density foams, and methods of preparing these foams and composite foams are described. Also described are biocompatible constructs which include single or double density biopolymer foams and extracellular matrix particulates and methods of preparing these constructs. The foams, composite foams, and biocompatible constructs of the invention can be used in tissue repair and reconstruction.

Biopolymer foams for use in tissue repair and reconstruction

Background: Peri-implant diseases include peri-implant mucositis, describing an inflammatory lesion of the peri-implant mucosa, and peri-implantitis, which also includes loss of supporting bone.

Methods: A literature search of the Medline database (Ovid), up to 21 January 2008 was carried out using a systematic approach, in order to review the evidence for diagnosis and the risk indicators for peri-implant diseases.

Results: Experimental and clinical studies have identified various diagnostic criteria including probing parameters, radiographic assessment and peri-implant crevicular fluid and saliva analyses. Cross-sectional analyses have investigated potential risk indicators for peri-implant disease including poor oral hygiene, smoking, history of periodontitis, diabetes, genetic traits, alcohol consumption and implant surface. There is evidence that probing using a light force (0.25 N) does not damage the peri-implant tissues and that bleeding on probing (BOP) indicates presence of inflammation in the peri-implant mucosa. The probing depth, the presence of BOP, and suppuration should be assessed regularly for the diagnosis of peri-implant diseases. Radiographs are required to evaluate supporting bone levels around implants. The review identified strong evidence that poor oral hygiene, a history of periodontitis and cigarette smoking, are risk indicators for peri-implant disease. Future prospective studies are required to confirm these factors as true risk factors.

Peri-implant diseases: diagnosis and risk indicators

http://www.tissueeng.net/lab/papers/124.pdf

Engineering microscale topographies to control the cell-substrate interface.

Porcelain veneers: a review of the literature.

Purpose The aim of this article was to review the current literature with regard to survival and success rates, along with the clinical procedures and outcomes associated with immediate and delayed implant placement Materials and methods A MEDLINE search was conducted of studies published between 1990 and June 2003 Randomized and nonrandomized clinical trials, cohort studies, case-control studies, and case reports with a minimum of 10 cases were included Studies reporting on success and survival rates were required to have follow-up periods of at least 12 months Results Thirty-one articles were identified Most were short-term reports and were not randomized with respect to timing of placement and augmentation methods used All studies reported implant survival data; there were no reports on clinical success Peri-implant defects had a high potential for healing by regeneration of bone, irrespective of healing protocol and bone augmentation method Sites with horizontal defects (HD) of 2 mm or less healed by spontaneous bone fill when implants with rough surfaces were used In the presence of HDs larger than 2 mm, or when socket walls were damaged, concomitant augmentation procedures with barrier membranes and bone grafts were required Delayed implant placement allowed for resolution of local infection and an increase in the area and volume of soft tissue for flap adaptation However, these advantages were diminished by simultaneous buccolingual ridge resorption and increased requirements for tissue augmentation Discussion Immediate and delayed immediate implants appear to be predictable treatment modalities, with survival rates comparable to implants in healed ridges Relatively few long-term studies were found Successful clinical outcomes in terms of bone fill of the peri-implant defect were well established However, there was a paucity of data on long-term success as measured by peri-implant tissue health, prosthesis stability, and esthetic outcomes Conclusions Short-term survival rates and clinical outcomes of immediate and delayed implants were similar and were comparable to those of implants placed in healed alveolar ridges

Immediate or early placement of implants following tooth extraction: review of biologic basis, clinical procedures, and outcomes.

Statement Of Problem. Gap measurements along margins are frequently used to assess the quality of single crowns. However, the number of gap measurements required for clinically relevant results in laboratory studies is not known. Purpose. This study estimated the minimum number of gap measurements on margins of single crowns to produce relevant results for gap analysis. Methods And Material. Ten all-ceramic crowns were fabricated on a master steel die. Gaps along crown margins were investigated in a scanning electron microscope on the master steel die without cementation and on replica dies after conventional cementation. Measurements were made in 100 μm steps according to 3 gap definitions. The initial number of measurements per crown (n = 230) was reduced to smaller subsets using both systematic and random approaches to determine the impact on the quality of results. Results. On the data of gap definition 1, reduction from 230 to about 50 measurements caused less than ±5 μm variability for arithmetic means. Analysis of standard errors showed slowly increasing values smaller than 3 μm, both indicating no relevant impact on the quality of results. Smaller data sizes yielded accelerated increase of standard errors and divergent variabilities of mean. The minimum of 50 measurements did not depend on gap definition or on cementation condition. Conclusion. Fifty measurements are required for clinically relevant information about gap size regardless of whether the measurement sites are selected in a systematic or random manner, which is far more than what current in vitro studies use. (J Prosthet Dent 2000;83:40-9.)

Determination of the minimum number of marginal gap measurements required for practical in-vitro testing.

Objective: We compared the performance of damping capacity assessment (Periotest™ device) to resonance frequency analysis (Osstell™ device) in the assessment of peri-implant bone loss in an in vitro experiment.

Material and methods: Screw-type oral implants were polymerized into acrylic blocks. Peri-implant bone loss was simulated by successively removing defined portions of material surrounding the implants in millimeter increments. Measurement values of both devices were compared by assessing the associated measurement errors, by calculating correlation analyses and drawing scatterplots, and by means of regression analysis referring to increasing bone loss.

Results: Both devices produced comparable results suggesting agreement of the measured implant stability values to the actual loss of peri-implant resin. There was a noticeable correlation of the Periotest™ and Osstell™ implant stability values.

Conclusion: The results of this experiment suggest agreement in predicting the actual implant stability with both the instruments with the Osstell™ instrument being the more precise device.

Resonance frequency analysis and damping capacity assessment. Part 2: peri-implant bone loss follow-up. An in vitro study with the Periotest and Osstell instruments.

Objectives The aims of this in vitro study were to evaluate reliability of the Osstell and Periotest devices in the assessment of implant stability and to perform a method comparison. Material and methods Commercial dental implants were inserted into bovine rib segments of different anatomical origins and densities. Repeated measurements were performed, varying (a) the torque-in force of the devices' attachment screw (the Osstell transducer and the ball attachment, insert for the Periotest device), (b) the insertion site bone quality, and (c) the thread exposure in simulated peri-implant bone defects. Results Both methods were comparably reliable and showed a strong association to each other in the classification of implant stability. As opposed to torque-forced screw attachment, the variations in bone composition, differences in inter-implant stability of adjacent implants, and peri-implant bone reduction were statistically significant for both methods. Conclusions Both non-invasive diagnostic devices seem to be useful in the long-term follow-up of implant integration.

Resonance frequency analysis and damping capacity assessment. Part I: an in vitro study on measurement reliability and a method of comparison in the determination of primary dental implant stability.

The present study investigated 124 stepped-screw implants (gritblasted and acid-etched surface) placed in 104 patients immediately after tooth extraction or implant explantation and followed between August 1990 and December 1996. Implants of varying diameters and lengths were used to cover a wide range of indications in both the maxilla and mandible; 68% of the implants supported single-tooth replacements. The study parameters included Plaque Index, Gingival Index, probing depth, Periotest values, and peri-implant bone loss. Statistical analysis according to Kaplan-Meier revealed a 97% survival rate.

/pdf/immediate-postextraction-implant-placement-with-root-analog-2gbe5mqxzp.pdf

Immediate postextraction implant placement with root-analog stepped implants: surgical procedure and statistical outcome after 6 years.

Titanium requires special ceramic systems for veneering. This study compared the three-point bending strength of three commercially available titanium ceramic systems with a NiCr-alloy with conventional ceramics. Three-point bend specimens 25 x 5 x 0.5 mm were cast from polyethylene patterns. After alpha-case removal, they were veneered with 8 x 5 x 1 mm of ceramics at the center of the bar. Specimens were tested in a universal testing machine without ageing, after thermocycling, and after 90 d storage in an electrolyte solution. Titanium-ceramic systems were found to have a significantly lower bond strength in comparison to the NiCr-ceramic system. One of the titanium ceramic systems had a significantly lower bond strength in comparison to the other systems investigated. It could be concluded that bonding between titanium and ceramics is obtainable; however, the achievable bonds strengths did not match the NiCr-ceramic control.

Heiner Weber

Papers

Determination of the minimum number of marginal gap measurements required for practical in-vitro testing.

Resonance frequency analysis and damping capacity assessment. Part 2: peri-implant bone loss follow-up. An in vitro study with the Periotest and Osstell instruments.

Resonance frequency analysis and damping capacity assessment. Part I: an in vitro study on measurement reliability and a method of comparison in the determination of primary dental implant stability.

Immediate postextraction implant placement with root-analog stepped implants: surgical procedure and statistical outcome after 6 years.

Three‐point bending strength of ceramics fused to cast titanium