In vitro pilot study comparing a novel implantoplasty sonic instrumentation protocol with a conventional protocol using burs.

BACKGROUND AND OBJECTIVES: The aim of implantoplasty (IP) is to remove titanium implant layers that have been contaminated and to smoothen the implant surfaces so they retain less plaque. However, existing IP methods are very invasive and reduce implant wall thickness. AIM: To investigate the suitability of novel sonic tips in IP and to compare this novel protocol with conventional abrasive procedures. MATERIALS AND METHODS: Thirty dental implants (Ø 4.1 mm, 10 mm length) were distributed in three groups and investigated according to the protocol of Sivolella et al., with modifications to the instrument's feed rate, the applied contact force, and the speed of implant rotations per minute. The upper third of the implant was processed with a diamond-coated bur (BUR) or novel non-diamond-coated sonic tips (AIRSCALER). After standardized IP, the surfaces were analyzed by tactile profilometry and scanning electron microscopy (SEM). Changes in implant weight, implant material loss, and implant fracture strength were assessed. RESULTS: The mean roughness (Ra , Sa ), implant material loss, and change in implant weight were significantly lower in the AIRSCALER group than in the BUR group, whereas the mean compression resistance values were significantly higher in the AIRSCALER group than in the BUR group. CONCLUSIONS: IP with uncoated sonic tips smoothes the surfaces and reduces structural loss of the implant in the area of microthreads. This new IP method could be of great clinical importance, especially for implants with microthreads and reduced diameter or wall thickness.

Use of 8-mm and 9-mm implants in atrophic alveolar ridges: 10-year results.

PURPOSE: The use of short implants can reduce the need for augmentative procedures prior to implant placement and, thus, morbidity and treatment time for patients with severely atrophied alveolar ridges. However, the inevitably less favorable crown-to-implant ratio is often associated with higher implant failure rates and greater marginal bone loss. The aim of this study was to evaluate the long-term survival and success rates of short implants in severely atrophic alveolar ridges retaining restorations on these short implants only. MATERIALS AND METHODS: In this study, 8-mm and 9-mm implants were inserted in atrophic alveolar ridges according to the manufacturer's protocol for the respective bone quality and loaded after 3 months of healing. Prosthetic restorations were supported only by short implants (not in combination with longer implants). After a mean observation period of 10.1 years (±1.9 years), all patients were re-examined clinically and radiographically. RESULTS: In this study, fifty-two 8-mm and 9-mm implants were placed in 14 patients. After 10.1 years, no implants and suprastructures had been lost. A mean marginal bone loss of 0.3 mm (±0.4 mm) was recorded. According to the Albrektsson criteria, all implants were successful; with respect to the more rigorous Karoussis et al criteria, four implants failed. CONCLUSIONS: The results of this long-term study suggest that the use of short implants results in marginal bone resorption and failure rates similar to those for longer implants. The higher crown-to-implant ratio did not seem to have any negative influence on implant success in this study.

Determining knee joint alignment using digital photographs.

The objective of this work is to find out how reliably knee joint alignment can be measured from a standardized photograph and what influence changes in the standing position have on the angles measured. The interrater, intrarater, and test-retest reliability were evaluated. The influence of image-object distance, the distance between the legs and leg rotation on the measured angles was evaluated. In addition to the digital photographs, 10 full-length radiographs were obtained in an upright position to determine whether the measured angles represent the anatomic axis or mechanical axis. There was high correlation between the interrater (ICC 0.997), intrarater (ICC 0.989) and test-retest reliability (ICC 0.904). Only slight deviation was found with the changes in radiograph-object distance (0 degrees -1.8 degrees ). With feet together varus malalignment was greater. Leg rotation showed a strong influence on the measured results (ICC 0.658). The angle measured in the digital photographs reflects the mechanical axis with only slight deviation (0.12 degrees -1.9 degrees ). The measurement of the clinical axis using standardized radiography is highly reliable and can be used for individual follow-up of varus and valgus malalignments.