Clinical Application Summary:
If a perforation has already happened inside of an implant preparation, I assess if I can still get a decent length implant placed and that this implant will NOT be any more than 3mm into the sinus. An implant 1-2mm into the sinus should heal uneventfully. If the sinus is perforated, I have my patients take Augmentin during the healing process. Be carefull with irrigating inside of the implant preparation when the sinus is perforated. (It might make the pateint jump in the chair!) Also, when possible, try to identify the cases where there may be a sinus perforation ahead of time. For these cases I do a sinus bump and throw some bone immediately before the implant.
How maxillary Sinus Membrane Perforation Affects Implant Survival and What You Can Do About It
Without exception, this happens after you already told the patient that the risk of complications is low, right? Then during the procedure you feel the floor of the sinus break and the patient feels water gushing into their nose. Crap! What happens now? Does this mean that mean your procedure is a failure?
This article will briefly discuss the complications associated with sinus perforations. Next, it will describe the associated effect on implant survival rate and finally provide some clinical suggestions about how to modify your management if a perforation happens.
Dental implants have been a very successful and predictable treatment choice in patients with sufficient amount of bone, which facilitates osseointegration of implants. However, in clinical practice, we are faced with clinical situations in which there is a limited amount of bone due to pneumatization of the sinus or resorption of alveolar bridge or both. This usually happens as a consequence of edentulism in posterior maxilla. The dentist must be aware of the possibility of sinus membrane perforation whether during instrumentation prior to implant placement or during implant insertion. As a matter of the fact, implant perforation of the maxillary sinus has been reported by Branemark et al. as early as 1984.
Complications associated with maxillary sinus membrane perforation:
The migration of bacteria into the sinus and the development of sinusitis remain the major complication. Complications are mainly related to having foreign body in the maxillary sinus such as migrated dental implants or the presence of bone substitutes used for sinus augmentation. In addition, non-osseointegrated implants can provide an oroantral fistula which enables communication with bacteria in oral cavity.
However, it’s important to note that recent animal and human studies indicate that implant penetration into the maxillary sinus does not cause sinus complications even when the length of implant penetration is more than 4 mm (Abi Najm et al. 2013, Jung et al. 2005).
Implant Survival Rate (ISR) associated with maxillary sinus perforation:
Studies have provided different perspectives on this issue. A study by Khoury in 1999 concluded that sinus membrane perforations negatively affect ISRs and correlate with increased implant failures especially after the first year of loading these implants.
Meanwhile, Abi Najm et al. in 2013 reported successful and uneventful osseointegration of implants penetrating into the sinus with an average follow up period of 9 years. Furthermore, Ferreira et al. in 2017 pointed out that survival rates are not affected by sinus membrane perforations and are similar to non-perforated sinus membranes.
Let’s take a deeper look at these studies again. Khoury’s study included evaluation of implant survival rates following perforations caused by sinus lift procedures and simultaneous implant placement. However, this study didn’t report the implant survival rate or the perforation size. In addition, he used different surgical approaches for sinus elevation procedures.
On the other hand, in addition to the retrospective studies by Abi Najm and Ferreira, in-vitro studies also confirm the successful osseointegration of implants in perforated sinus membranes such as a study by Jung et al. in 2005 on dogs. Furthermore, as indicated above, implant penetration into the sinus membrane was not correlated with further complications. So it is reasonable to assume that there is no statistically significant difference in implant survival rates between implants in perforated and non-perforated sinus membranes.
However, it is not as simple as it looks…
High ISR (implant survival relates) in perforated sinuses has been attributed to suitable management of these perforations. Some studies recommended using a collagen membrane over the perforation area (Ferreira et al. 2017, Kim et al. 2016), other studies used a mixture of alloplastic material such as hydroxyapatite and autogenous bone chips stabilized by fibrin glue to manage these perforations (Khoury 1999). Platelet Rich Fibrin (PRF) is now a popular material to use to repair sinus perforations.
Furthermore, studies (Jung et al. 2005, Abi Najm et al. 2013) recommended that the perforation size does not exceed 4 mm as this will allow the sinus membrane mucosa to cover the perforated parts otherwise, it will cause thickening of sinus membrane around implants rather than covering it although this is not associated with sinus complications.
In conclusion, maxillary sinus membrane perforations have been viewed less importantly in relation to success rates of implants; however, this is attributed to a good management of these perforations which maintains the high success rate of implants in such cases.
Stay tuned for upcoming articles in “Short vs Long Implants.” We will cover how different lengths of implants that are available in the market correlate to different success rates of implants.
Fouad Khoury. Augmentation of the sinus floor with mandibular bone block and simultaneous implantation: a 6-year clinical investigation Int J Oral Maxillofac Implants. 1999 Jul-Aug;14(4):557-64.
Ferreira et al. Effect of Maxillary Sinus Membrane Perforation on Implant Survival Rate: A Retrospective Study. Int J Oral Maxillofac Implants. 2017 Mar/Apr;32(2):401-407.
Kim et al. Evaluation of clinical outcomes of implants placed into the maxillary sinus with a perforated sinus membrane: a retrospective study.. Maxillofac Plast Reconstr Surg. 2016 Dec 5;38(1):50
Abi Najm et al. Potential adverse events of endosseous dental implants penetrating the maxillary sinus: long-term clinical evaluation. Laryngoscope. 2013 Dec;123(12):2958-61.
Jung et al. A retrospective study of the effects on sinus complications of exposing dental implants to the maxillary sinus cavity. 2007 May;103(5):623-5