1. Multiple Condensing Thread Design and Implant Stability In Vitro
Georgios E. Romanos, DDS, PhD, Prof Dr med dent*; Wei Hou, PhD,
Rafael A. Delgado-Ruiz, DDS, MSc, PhD2
School of Dental Medicine, Stony Brook University, Stony Brook, New York

2. Implant thread design has a fundamental impact on implant primary stability (PS). The aim of this study was to evaluate the PS of dental implants with multiple condensing threads (MCT) in vitro.

3. 160 MCT-designed implants were placed in cellular rigid polyurethane foam bone blocks (Sawbone, Pacific Research Laboratories, Vashon, WA, USA), simulating type II and type IV bone density. Two different types of implants (SBII and SBIII, Anker, Alliance Co.) were evaluated for implant stability. Implants with diameters of 3.5 mm and 4.0 mm and lengths of 11.5 mm (Fig. 1) were placed into bone blocks after drilling the osteotomies with 800 rpm. PS was recorded using RFA (Penguin and Osstell devices) and Periotest. Statistical comparison between SBII and SBIII was performed with the t-test.
Fig. 1: SB II and SB III Implants used in this experiment. Two diameters were used per each implant group.

4. The data showed that all implants had a very good PS for all evaluation methods and high reliability of the results due to the consistency in measurements (Tables 1 and 2). In soft bone, the SBII was higher (p < ) for 4.0 mm diameter implants.
All other implant groups did not show any statistical differences. Narrow or wider implants did not have any difference in terms of implant PS (p > 0.05).

5. The MCT-designed implants have an excellent PS in artificial bone
The MCT-designed implants have an excellent PS in artificial bone. Due to the condensation effect of the thread design, the narrow diameter does not influence negatively the implant stability.