Influence of Schneiderian Membrane Perforations on the Prognosis and Outcomes of Lateral Window Sinus Lift Operations: A Retrospective Case Series Study

Abstract

Introduction: This study analyzed the influence of Schneiderian membrane perforations covered with collagen membranes on the success of augmentation and implantation as well as the influences of smoking, radiation and chemotherapy. Patients and Methods: 182 consecutive operated patients with a total of 298 augmented sinuses and 833 inserted implants were analyzed retrospectively. Success rates of sinus augmentations with perforated and unperforated Schneiderian membranes were compared. Results: Perforations of the Schneiderian membrane occurred in 23.2% (p< 0.001). Success rate decreased from 89.4% (p< 0,001) at unperforated sinuses to 80.0% (p=0.005) at perforated sinuses for the irradiated patients and from 95.6% (p< 0,001) at unperforated sinuses to 89.8% (p< 0.001) at perforated sinuses for patients not treated with radiation therapy. Similar results were found for the implant loss rate, which was highest for perforated sinuses at irradiated patients – 43.9% (p=0.023) – and lowest for unperforated sinuses at not irradiated patients – 4.5% (p< 0.001). Comparing membrane perforation to lost implants and failure rate a statistically significant difference could be detected (p=0,029). Conclusions: Although Schneiderian membrane was covered with collagen membranes in all cases, perforations still have a negative impact on success rates of augmentation and implant survival. Possible improvements of this method should be investigated in following studies. Keywords: Radiation therapy; Smoking; Chemotherapy; Sinus augmentation; Implant loss; Implant survival;