Influence of flap design on peri-implant interproximal crestal bone loss around single-tooth implants.

The anterior maxilla represents a therapeutic challenge for single-tooth replacement with implants. The surgical trauma delivered to soft and hard tissues during implant placement can influence the future esthetic result. The clinician should use surgical techniques that prevent esthetic complications, such as increased crown length or loss of interdental papillae, without compromising osseointegration. This prospective study investigated the interproximal crestal bone loss occurring after placement of single-tooth implants using 2 different flap designs: a widely mobilized flap design that included papillae, and a limited flap design that protected papillae. The interproximal crestal bone loss was of practical importance and statistically significantly less following the use of a limited flap design versus the widely mobilized flap procedure.

The Frialit-2 implant system: five-year clinical experience in single-tooth and immediately postextraction applications.

In an observational study of 696 Frialit-2 implants in 376 patients that was carried out between 1990 and 1995, implants of varying diameters and lengths were delivered for a range of indications in the maxilla and mandible. Single-tooth replacement was performed in 42% of cases; of these, 22.4% were placed immediately following extraction. Study parameters (Plaque Index, Gingival Index, probing depth, Periotest value, and peri-implant bone loss) are reported in detail. Statistical analysis is based on a 97.6% rate of recall. The overall success rate was found to be 96% using the Kaplan-Meier statistical analysis. No difference was apparent between single-tooth applications and prosthesis restorations.

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

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.

Area-dependent enlargement ratios of panoramic tomography on orthograde patient positioning and its significance for implant dentistry.

The aim of this work was to study the behavior of vertical and horizontal enlargement ratios in panoramic tomography in various implant regions of the maxilla and the mandible. A method is presented that admits determination of regional enlargement ratios as a function of the implant region. Clearly defined characteristics of the implant body (Frialit-2 implants) are used as reference points. The vertical enlargement ratio varied between 1.21 and 1.29 on optimal orthograde adjusted tomographs, depending on the measured area. The horizontal enlargement ratio at the coronal end of the implant varied between 1.15 and 1.35. As it is below the vertical value in the lateral tooth area, this contributes to the distortion of the implant structures depicted. The horizontal enlargement at the apical end of the implant varies between 1.12 and 1.44. The difference in horizontal enlargement ratios also causes a distortion of the implant structures shown on the panoramic tomograph. Based on this study scenario, panoramic tomography may be well suited to preimplant diagnosis, particularly in the vertical dimension. With regard to transparent templates designed for implant placement, an enlargement of 1.3 in the perpendicular line and 1.35 in the horizontal line is proposed.

Influence of the implant abutment on the Periotest value: an in vivo study.

OBJECTIVE: Periotest values for dental implants depend on the type of prosthetic abutment utilized for the restoration. If Periotest value cannot be measured at the single crown, the Periotest values used for comparison must be derived from the same type of superstructure. METHOD AND MATERIALS: Fifty-nine patients were selected from a regular follow-up program. At the end of the healing period, the Periotest values of Frialit-2 implants were measured at the gingiva former and abutment. The values were then compared with the Periotest measurements obtained at the placement of the final single crown and during the first follow-up examination. RESULTS: Compared to values measured at single crowns, the Periotest value measured at gingiva formers decreased on average by 3.5. The measurement of the abutment revealed a decrease of 1.7. Until the first recall and under functional loading of implants, the Periotest value increased on average by 1.8. These differences significantly differed from 0. CONCLUSION: If measurements at different abutments such as crown abutments or single crowns are necessary, comparison of the Periotest values in accordance with the given mean values will lead to more precise results. It is recommended that Periotest measurements be performed for the first and subsequent prostheses, during all prosthetic stages, to allow comparison if some parts of the prosthetic abutment have to be replaced.

Leadership, governance and management in dental education - new societal challenges.

Dental schools around the world face new challenges that raise issues with regard to how they are governed, led and managed. With rapid societal changes, including globalization and consumerism, the roles of universities and their funding have become intensely debated topics. When financial burdens on universities increase, so does the pressure on dental schools. This is exacerbated by the relative expense of running dental schools and also by the limited understanding of both university managers and the public of the nature and scope of dentistry as a profession. In these circumstances, it is essential for dental schools to have good systems of leadership and management in place so that they can not only survive in difficult times, but flourish in the longer term. This paper discusses the concept of governance and how it relates to leadership, management and administration in dental schools and hospitals. Various approaches to governance and management in dental schools on different continents and regions are summarized and contrasted. A number of general governance and leadership issues are addressed. For example, a basic principle supported by the Working Group is that an effective governance structure must link authority and responsibility to performance and review, i.e. accountability, and that the mechanism for achieving this should be transparent. The paper also addresses issues specific to governing, leading and managing dental schools. Being a dean of a modern dental school is a very demanding role and some issues relating to this role are raised, including: dilemmas facing deans, preparing to be dean and succession planning. The importance of establishing a shared vision and mission, and creating the right culture and climate within a dental school, are emphasized. The Working Group advocates establishing a culture of scholarship in dental schools for both teaching and research. The paper addresses the need for effective staff management, motivation and development, and highlights the salience of good communication. The Working Group suggests establishing an advisory board to the dean and school, including lay persons and other external stakeholders, as one way of separating governance and management to some extent and providing some checks and balances within a dental school. Several other suggestions and recommendations are made about governance, management and leadership issues, including the need for schools to promote an awareness of their roles by good communication and thereby influence perceptions of others about their roles and values.

Effect of occlusal wear on bone loss and Periotest value of dental implants.

PURPOSE: Occlusal overload may contribute to the loss of osseointegration of oral implants, so some clinicians are reluctant to place implants in patients with signs of bruxism. This study evaluated the effect of occlusal wear as a probable sign of bruxism on bone loss and implant stability. MATERIALS AND METHODS: The study investigated 379 patients who had worn implant-retained or implant-supported restorations for many years. Occlusal wear, patient age and gender, time of prosthetic loading, jaw, location in the dental arch, implant diameter, prosthesis construction, occlusal material, periimplantitis, and loosening of the prosthetic construction were recorded. One implant from each patient was selected for radiographic and Periotest measurements. The implant with the highest bone resorption was chosen. A forward stepwise multiple linear regression analysis was performed to analyze the effect of the explanatory variables on Periotest value and radiographic bone loss. RESULTS: The statistical models could account for part of the variation in bone loss rate and Periotest value. Some influence of time of loading, jaw, and implant diameter on bone loss or Periotest value was formally established. Occlusal wear failed to have any statistical impact on vertical annual bone loss rate or Periotest value. CONCLUSION: This study gave no indication that implants in patients with occlusal wear have an increased bone loss rate or Periotest value.

A clinical evaluation of some factors affecting image quality in panoramic radiography.

AIM: To evaluate the suitability of panoramic radiographs obtained with two different machines for clinical use. MATERIAL AND METHODS: Three observers assessed 111 pairs of panoramic radiographs taken with the Scanora (Soredex, Orion Corp., Helsinki, Finland) programme 001, and the Orthophos Plus (Sirona, Bensheim, Germany), programme P1 respectively, for visualisation of seven anatomical structures on each side, on a 5-point scale where 1 = very good. The median values were computed and a descriptive analysis performed. Interrater and intrarater agreement were expressed as weighted kappa. RESULTS: The median values of both Scanora and Orthophos radiographs were the same, scoring 2. The intra- and inter-observer agreement was generally poor and similar for both machines. CONCLUSIONS: The two panoramic machines were both given good ratings for evaluation of anatomical structures. The differences were very small and suggest that both machines are suitable for clinical use.