A retrospective study of short implants with two different surfaces placed in lateral aspects of the maxilla with limited height of alveolar ridge: 36 months of follow-up

Introduction
The problem of implant rehabilitation for maxillary atrophy is crucial. It involves the use of short implants or sinus-lift and the establishment of standard implants.

Objectives
To evaluate the efficacy of short (6 mm long) dental implants of two different surfaces in 36 months of follow-up.

Material and methods
Thirty generally healthy patients with good oral hygiene, treated with short implants (6 mm long and 4 mm in diameter) due to individual missing teeth in the lateral aspects of maxilla were qualified for the study. Patients were divided into two equal groups. The first group consisted of patients treated with sandblasted and additionally etched (SLA) implants, whereas in the second group, electrochemically hydroxyapatite-coated implants were used. Periodontal indexes such as pocket depth probing (PPD), height of keratinized gingiva (HKT), recession depth/width, and clinical attachment level were evaluated on the day of surgery and after 36 months. Additionally, the orthopantomographic X-ray was carried out in order to assess the marginal bone loss (MBL).

Results
The success rate in both groups were 100%. The mean MBL was 0.34 mm for SLA and 0.33 mm for hydroxyapatite (HA) implants, with no statistically important differences. The only statistically important differences were seen in PPD and HKT parameters: 2.53 ± 0.83 mm vs. 1.47 ± 0.64 mm, and 2.27 ± 0.96 mm vs. 3.30 ± 1.08 mm for SLA and HA implants, respectively.

Conclusions
Short implants can be considered as a predictable method of treatment in the lateral aspects of maxilla. There are no differences in survival rate between SLA- and HA-surfaced implants in 36 months of follow-up.