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Background The outcome of the evaluation of impression techniques accuracy may improve the selection criteria for an ideal technique. The aim was to evaluate the accuracy of the open and closed tray techniques for implant impressions, in a partially edentulous maxilla, replaced with a three-unit fixed partial denture, as well as to assess the effect of implants parallelism on accuracy. Material and methods This is an experimental in vitro study to evaluate impressions accuracy of a simulated area restored with an implant retained FPD, using the open and closed tray implant impression techniques. The effect of implant position angulation, parallelism, and implant systems (Straumann, SIC Invent, Osstem) was also evaluated. Three custom-made acrylic resin test models were prepared with two parallel and two non-parallel implants, on either side of a maxillary arch. One hundred and ninety-two impressions were made using monophase VPS impression material. Their master casts were obtained and evaluated for the horizontal and vertical discrepancy. The casts were scanned using a model scanner. The distances between the two reference points were measured. Results The Straumann and SIC Invent implants showed no statistically significant differences (Mann-Whitney U test), regarding accuracy for both the open and closed tray impression techniques ( P = 0.667 and P = 0.472). There were no significant differences for the parallel and non-parallel implants ( P = 0.323 and P = 0.814), respectively, while the Osstem system showed statistically significant differences for both the open and closed tray impression techniques ( P = 0.035) and between the parallel and non-parallel implants ( P = 0.045). For the vertical discrepancies, significant differences were detected (chi-square test) between the open and closed tray impression techniques ( P = 0.037). Conclusions Within the limitations of this study, there were generally no significant differences between open and closed, although better results were obtained for the open tray techniques. On the use of the non-parallel implants, the open tray technique provided a better result than the closed tray technique.

HighlightsA 24-year-old woman with cleidocranial dysplasia (CCD)refused orthodontic treatment.Fourteen screw basal implants were inserted in both jaws.The implants were immediately loaded 3 days later with fixed prostheses.The patient was satisfied and presented excellent oral health 3 years later.Basal-implant supported fixed prostheses can improve aesthetics and quality of life.

Background: Implant protrusion into the nasal and maxillary sinuses presents a challenge in cases of severely resorbed maxillae. Aim: The aim of this study was to evaluate the clinical and radiographic effects of BECES ® implant penetration depth into the nasal and maxillary sinuses. Setting and Design: This was an observational study conducted in a tertiary institution. Materials and Methods: Forty-nine BECES ® implants were inserted into the maxilla of patients who presented with severely resorbed ridges but no history of sinusitis. Forty-five implants protruded into the sinus cavities. Patients were examined clinically and radiographically at 1 week and 3, 6, 12, and 18 months after insertion. Maxillary sinus health, survival and success rates, and peri-implant health were assessed using the plaque index (PI), calculus index, modified gingival index (MGI), and probing pocket depth (PPD). Statistical Analysis: Wilcoxon signed-rank test and Mann–Whitney test were used in this study. Results: Four (8.16%) of the 45 implants that penetrated the cavities reached the sinus floor without disrupting the membrane; the penetration depth was ≥4 mm in 20 implants (44.44%) and <4 mm in 25 (55.56%). No patient showed clinical or radiographic signs of sinusitis during the observation period. There were significant differences in the PI, MGI, and PPD values between baseline and the 18-month follow-up with no association with the penetration depth. All implants showed radiographically direct bone-to-implant contact. Where the implant tip barely reached the sinus floor, the membrane healed uneventfully while when deeply penetrating the sinus, the membrane healed around the implant but did not cover the tip. All prostheses and implants survived during the observation period. Conclusion: Penetration depth of polished implants with cortical engagement into the maxillary sinus or the floor of the nose does not negatively affect implant survival, the success rate of the treatment, nor peri-implant soft-tissue health. It also does not provoke the development of sinusitis.