Survival and patient satisfaction of short implants during the first 2 years of function: a retrospective cohort study with 694 implants in 416 patients.

OBJECTIVES: The present study aimed to evaluate the influence of implant length on implant survival and patient satisfaction during the first 24 months in function. MATERIAL AND METHODS: A retrospective cohort of 312 "short" Straumann(®) SLActive(®) implants (length ≤ 8 mm) in 224 patients, which were inserted between 2008 and 2010 in private practice, were evaluated. The mean observation period was 26.7 ± 9.7 months. Three hundred and eighty-two Straumann SLActive(®) implants in 192 patients with a length ≥ 12 mm served as control group. The mean observation period in the control group was 28.3 ± 10.1 months. Implant survival rate, crown-to-implant ratio, resonance frequency analysis, and patient satisfaction were evaluated. RESULTS: Implant survival rate was 99% in the test vs. 98.7% in the control group. The crown-to-implant ratio was significantly higher in the control group (P < 0.0001). Resonance frequency analysis showed slightly higher values for the short implants. There was a tendency to higher satisfaction (Oral Health Impact Profile [OHIP]) in the test group without statistical significant differences but a high overall satisfaction in both groups. CONCLUSION: Within the limits of the present investigation, implant length had no significant influence on implant survival during the first 24 months of function of the specific implant system with hydrophilic surface (SLActive(®) ). Further follow-up studies are required to evaluate long-term results of the reduced implant length.

Tautomer identification and tautomer structure generation based on the InChI code.

An algorithm is introduced that enables a fast generation of all possible prototropic tautomers resulting from the mobile H atoms and associated heteroatoms as defined in the InChI code. The InChI-derived set of possible tautomers comprises (1,3)-shifts for open-chain molecules and (1,n)-shifts (with n being an odd number >3) for ring systems. In addition, our algorithm includes also, as extension to the InChI scope, those larger (1,n)-shifts that can be constructed from joining separate but conjugated InChI sequences of tautomer-active heteroatoms. The developed algorithm is described in detail, with all major steps illustrated through explicit examples. Application to approximately 72,500 organic compounds taken from EINECS (European Inventory of Existing Commercial Chemical Substances) shows that around 11% of the substances occur in different heteroatom-prototropic tautomeric forms. Additional QSAR (quantitative structure-activity relationship) predictions of their soil sorption coefficient and water solubility reveal variations across tautomers up to more than two and 4 orders of magnitude, respectively. For a small subset of nine compounds, analysis of quantum chemically predicted tautomer energies supports the view that among all tautomers of a given compound, those restricted to H atom exchanges between heteroatoms usually include the thermodynamically most stable structures.

Implant survival and patient satisfaction of reduced diameter implants made from a titanium-zirconium alloy: A retrospective cohort study with 550 implants in 311 patients.

The aim of the study was to evaluate implant survival of reduced-diameter implants compared to regular-diameter implants. A retrospective evaluation of 154 Straumann Bone Level Roxolid® implants (diameter 3.3 mm) with SLActive®-surface in 107 patients, which were inserted between 2009 and 2010 in private practice, was performed. The mean observation period was 22.4 ± 8.2 months. 396 Straumann SLActive® implants (4.1 mm and 4.8 mm) in 204 patients, with an observation period of 28.4 ± 10.1 months served as control group. Implant survival rate, resonance frequency analysis and patient satisfaction were evaluated. The implant survival rate was 97.4% in the test vs. 98.5% in the control group. Resonance frequency analysis showed statistically significant lower values for the reduced-diameter implants. Patient satisfaction showed no significant difference between the test and the control group. Reduced-diameter implants displayed high survival rates during the period investigated and represent a convincing treatment alternative. Long-term follow-up investigations confirmed the high implant survival rates of 96.8% (after 69.7 ± 12.3 months) in the test group and 98.5% (after 76.0 ± 13.6 months) in the control group.