Dental implants with locking taper connection versus screwed connection: microbiologic and scanning electron microscope study.

The aim of this study is to carry out an analysis of the Fixture-Abutment Interfaces (FAI), comparing different connection systems, to evaluate the role of geometric discrepancy, which is present between the abutment and the fixture, in favoring the permeability to bacterial colonization. Two types of commercially available FAI were studied, 16 screwed FAI (Sweden-Martina Italia) (4 of Ø 3.8 mm diameter, 4 of Ø 4.7 mm diameter, 4 of Ø 5.7 mm diameter and 4 of Ø 6.7 mm diameter) and 4 FAI (Bicon) (Ø 3.5mm diameter). The assays were carried out in vitro, placing the different dental implants in contact with broth culture of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Streptococcus pyogenes to test the infiltration inside the FAI. Furthermore, scanning electron microscope (SEM) analysis was carried out to evaluate the gap at the fixture-abutment interface. In all the locking taper FAI and in the screwed FAI with a diameter of 3.8 mm there was no trace of bacterial infiltration of the species examined. In the screwed FAI with a diameter of 4.7 mm, 5.7 mm and 6.7 mm there was an increasing level of bacterial infiltration in relationship to the diameter. Therefore, this paper shows that there exists an important correlation between the diameter of the screwed implant and the permeability to microbic infiltration that is directly proportional to the diameter of the implant.

Further evaluation of microswitch clusters to enhance hand response and head control in persons with multiple disabilities.

This study was a further evaluation of microswitch clusters (combinations of two microswitches) to improve adaptive responding together with correct head position in two persons with multiple disabilities. The two participants were 19.7 and 6.6 yr. old and had profound intellectual disabilities, spastic tetraparesis, and visual impairment. They were initially taught an adaptive hand response that activated a pressure microswitch and produced favorite stimulation. Thereafter, their performance of the hand response produced favorite stimulation only when it was combined with a correct head position (detected through a mercury microswitch). Analysis showed that both participants increased the frequency of the hand response and, subsequently, the percentage of times they emitted this response in combination with correct (upright) head position. In essence, they were able to coordinate constructive occupation with exercise of appropriate posture. Performance was maintained at a 2-mo. postintervention check.

Microswitch clusters to enhance adaptive responses and head control: a programme extension for three children with multiple disabilities.

PURPOSE: We assessed the possibility of extending adaptive responding and head control in three children with multiple disabilities through the use of microswitch clusters. METHOD: The children had previously learned to perform an adaptive hand response and to control head position during that response. They were now taught one or two new adaptive responses (foot lifting, leg touching, or vocalization) and to combine such responses with appropriate head position. Microswitch clusters served to ensure that an adaptive response was followed by positive stimulation only if it was combined with appropriate head position. RESULTS: The results were positive with the children learning the new adaptive responses and combining them with appropriate head position. This performance was maintained during two- or three-month post-intervention checks. During these checks, the children were also successful in using the old adaptive hand response with appropriate head position. CONCLUSIONS: The use of microswitch clusters was effective to extend the level of adaptive responding and enhance appropriate head position during this responding. This outcome, which indicates a successful technical replication and procedural extension of previous work in the area, has positive practical implications for educational and occupational programmes for children with multiple disabilities.

Microswitch clusters to support responding and appropriate posture of students with multiple disabilities: three case evaluations.

PURPOSE: This study extended the evaluation of microswitch clusters to support responding and appropriate posture with three students with multiple disabilities. METHOD: Initially, a baseline level was established for the target response selected for each student. Then, Intervention I was implemented to increase the frequency of that response through the presentation of favourite stimuli. During Intervention II, the response was followed by favourite stimuli only if the microswitch cluster detected it in combination with appropriate posture. Post-intervention checks were carried out within 2 or 3 months from the end of Intervention II. RESULTS AND CONCLUSIONS: All students showed an increase in the frequency of the target response during Intervention I and in the percentage of times the response occurred in combination with appropriate posture during Intervention II. These changes lasted over time. The importance of microswitch clusters to enhance the performance of students with multiple disabilities was underlined.

Extending the use of familiar microswitches to difficult daily situations: two case evaluations.

This study assessed the possibility of successfully extending the use of familiar microswitches by two adults with multiple disabilities to a difficult, standing-with-support situation. Analysis showed that the introduction of the familiar microswitches into this situation increased the participants' constructive engagement; they had repeated contacts with the microswitch systems and activated them fairly consistently. For one of the participants, improvement also occurred in terms of mood (smiling) and standing time.

Microswitch clusters to enhance non-spastic response schemes with students with multiple disabilities.

PURPOSE: The study explored whether the use of microswitch clusters could enhance the performance of correct (non-spastic) response schemes by two students with multiple disabilities. METHOD: The study started with baseline on the two responses selected for each student. Then, intervention was implemented on the first response. This was followed by new baseline and intervention on the second response. Subsequently, intervention sessions on the two responses were alternated. Post-intervention checks were carried out over periods of 4 and 2.5 months. RESULTS AND CONCLUSIONS: Both students had an increase in correct response schemes and, conversely, a decline in spastic response schemes. The importance and practicality of microswitch clusters to enhance appropriate responding in students with multiple disabilities were discussed.