Is clinical experience important for obtaining the primary stability of dental implants with aggressive threads? An ex vivo study

The aim of this study was to investigate the clinicians? experience on maintaining the primary stability of implants with aggressive threads belonging to a novel dental implant system. Three hundred implants with aggressive threads were inserted in fresh bovine ribs mimicking Type IV bone by five clinicians which were classified according to their previous experience of total number of implant insertion. An independent examiner measured the primary stability of all implants after insertion by using resonance frequency analysis (RFA), electronic percussive testing (EPT) and removal torque methods. No significant differences were detected between the stability values measured by the clinicians (p0.05). Significantly higher stability values were detected in the secondary insertion of the non-experienced clinician as compared to her initial insertion values (p >0.05). No significant differences were detected between the first and second measurements of the other clinicians (p< 0.05). Within the limitations of this ex-vivo study, it may be concluded that experience does not play an important role in maintaining the stability of implants with aggressive threads

How Precise Is Dental Volumetric Tomography in the Prediction of Bone Density?

Objectives. The aim of this study was to review the bone density assessment techniques and evaluate the macroscopic structure of bone specimens scored by Hounsfield Units (HUs) and decide if they are always in congruence. Methods. The mandible of a formalin-fixed human cadaver was scanned by dental volumetric tomography (DVT) for planning of the specimen positions and fabrication of a surgical guide and a surgical stent was fabricated afterwards. Bone cylinders of 3.5 mm diameter and 5 mm length, were excised from the mandible using the surgical stent with a slow speed trephine drill. After removal of the cylinders two more scans were performed and the images of the first scan were used for the determination of the HU values. The removed bone cylinder was inspected macroscopically as well by micro-CT scan. Results. The highest HU values were recorded in the interforaminal region, especially in the midline (408–742). Posterior regions showed lower HU values, especially the first molar regions (22–61 for the right; 14–66 for the left first molar regions). Conclusion. Within the limitations of this pilot study, it can be concluded that HU values alone could be a misleading diagnostic tool for the determination of bone density

Alternative impression technique for multiple abutments in difficult case to control

BACKGROUND: Even though excellent impression materials are now available for making accurate replication for hard and soft tissue, the numerous dentists have faced lots of obstacles in making simultaneous impressions of multiple abutments. CASE DESCRIPTION: This article describes a modified method of tray fabrication using auto-polymerizing acrylic resin and impression technique for multiple prepared teeth in cases with limitations and difficulties in taking dental impressions. CLINICAL IMPLICATION: This segmental tray technique has several advantages, including higher impression quality, fewer impressions, and being more comfortable for the patient and less stressful for the clinician.ope

The use of definitive implant abutments for the fabrication of provisional crowns: a case series

Purpose: The anterior region is a challenge for most clinicians to achieve optimal esthetics with dental implants. The provisional crown is a key factor in the success of obtaining pink esthetics around restorations with single implants, by soft tissue and inter-proximal papilla shaping. Provisional abutments bring additional costs and make the treatment more expensive. Since one of the aims of the clinician is to reduce costs and find more economic ways to raise patient satisfaction, this paper describes a practical method for chair-side fabrication of non-occlusal loaded provisional crowns used by the authors for several years successfully

Complication rates and patient satisfaction with removable dentures

PURPOSE. The purpose of this clinical study was to evaluate the frequency and type of prosthetic complications in relation to type and properties of removable dentures and to investigate the influence of these complications and several data about the existing dentures on patient satisfaction. MATERIALS AND METHODS. Ninety nine patients (44 males and 55 females) wearing removable dentures have been included in the study. The complications of the patients were recorded; patient satisfaction was determined with a Visual Analog Scale (VAS) and the relationship of complications and patient satisfaction with several data about the dentures such as denture age, type of denture, centric relation and vertical dimension was investigated. Kruskal Wallis, Mann Whitney U and Chi square tests were used for statistical analyses. The results were evaluated statistically at a significance level of P<.05. RESULTS. Need for addition of artificial teeth for dentures with correct centric relations was found to be significantly lower than dentures with wrong centric relations (P<.01). Loss of retention, ulcerations and high vertical dimension affected the VAS chewing ability scores negatively and ulcerations affected the VAS phonation scores negatively (P<.05). CONCLUSION. Considering the results of this study, it can be concluded that loss of retention, ulcerations and high vertical dimension caused patient dissatisfaction. Additionally, dentures with wrong centric relations caused need for addition of artificial teeth. [J Adv Prosthodont 2012;4:109-15

Mandibular 2-Implant Overdentures Improve Oral Health-related Quality of Life More Than Conventional Dentures, But There Are Cultural Differences

Subject

The influence of framework material on stress distribution in maxillary complete-arch fixed prostheses supported by four dental implants: a three-dimensional finite element analysis

The purpose of the present study was to compare the stress distribution patterns of four materials used for the framework of All-on-4 prostheses. Following framework materials were evaluated: PEKK, PEEK, titanium, and monolithic zirconia. Bilateral 150 N axial and oblique loads were applied in the first molar region and analyzed using FEA. The highest maximum principal stress and minimum principal stress values in cortical bone were found to appear with PEKK and PEEK frameworks around the posterior dental implants upon oblique loading. The fabrication of frameworks from rigid materials in All-on-4 prostheses reduces stress in dental implants and peri-implant bone when the distal implants are tilted 30 degrees

Evaluation of Possible Prognostic Factors for the Success, Survival, and Failure of Dental Implants

Purpose:To analyze the prognostic factors that are associated with the success, survival, and failure rates of dental implants.Material and Methods:Data including implant sizes, insertion time, implant location, and prosthetic treatment of 1656 implants have been collected, and the association of these factors with success, survival, and failure of implants was analyzed.Results:The success rate was lower for short and maxillary implants. The failure rate of maxillary implants exceeded that of mandibular implants, and the failure rate of implants that were placed in the maxillary anterior region was significantly higher than other regions. The failure rates of implants that were placed 5 years ago or more were higher than those that were placed later.Conclusions:Anterior maxilla is more critical for implant loss than other sites. Implants in the anterior mandible show better success compared with other locations, and longer implants show better success rates. The learning curve of the clinician influences survival and success rates of dental implants