Biology, aesthetics and background

From 18–20 October, more than 430 participants interested in Oral Regeneration came together to attend Osteology Paris 2018. In line with the topic of the congress ‘De la biologie à l’esthétique’, seven international and 31 national speakers covered a broad spectrum of topics in their lectures and workshops – and helped to strike a balance between theory and practice. But what were the specific topics covered behind the congress title?

The start of the symposium was dedicated to practical workshops, where participants had the opportunity to increase their dexterity. The Osteology Foundation contributed two workshops to the congress programme. Daniel Thoma from the University of Zurich broadened the knowledge of the attendees with the workshop on ‘Soft tissue management with a collagen matrix of stable volume’, while Maurício Araújo from Brazil covered ‘Extraction socket management for predictable ridge preservation’ in his practical etude.

Sinus in the spotlight

In the special sinus forum on Thursday afternoon, all talks focussed on the topic of sinus floor elevation. In one of the presentations, Mathias Rzeznik discussed contraindications. He distinguished between absolute and partial contraindication for bone augmentation. As absolute he listed, e.g. osteonecrosis, radiotherapy, immune deficiency, addictions, mental issues, as well as vitamin D deficiency. The latter is a new absolute contraindication, he explained, and he advised checking the vitamin D level of patients and to substitute if necessary. For the sinus floor elevation in particular, he also mentioned cystic fibrosis, tumours of the maxilla and patients under 16 years of age as absolute contraindication. As relative contraindications, lack of oral hygiene, untreated cardiomyopathies and smoking (>10 cigarettes per day) were listed. He advised, “Ask yourself whether there are risks of infections due to the surgery itself? And what about polyps, blocked sinuses, chronic sinusitis, or aspergillosis?”

Steven Wallace, who also presented in the Sinus Forum, said that overall sinus floor elevation is very predictable, with > 1400 articles published showing this successful concept. He divulged the two lessons learned in many years of experience. Firstly, “It’s not all about graft material”, he advised. The following also play an important role in successful treatment: the implant surface, the blood supply, space making materials and a sufficient healing time. Secondly, embrace new surgical protocols and technologies, such as piezo surgery (low complication rate), Osteoplasty (low perforation), the DASK technique, simplified antrostomy design, as well as Osseodensification.  He also advised that large cysts can be handled intraoperatively with a syringe, and that you can repair almost every perforation. “They don’t have an impact on implant survival”, he said.

Aspects of oral regeneration

On Friday, in the main programme, all aspects of Oral Tissue Regeneration therapies were addressed.

Markus Seiler explained that the limitation of maximal 4 mm augmentation with GBR procedures can be overcome by the use of titanium meshes, but at the expense of slightly higher complication rates. He presented a novel customizable 3D titanium mesh. First studies and case series have demonstrated the success of this concept, and meanwhile two-year data are already available. As an indication of its application, he mentioned type II-IV defects based on Terheyden (2010).

A different topic was addressed by Guillaume Heller. He discussed the human factor and said that the human itself is always the weakest link. When an error occurs, he said, one should ask, “How could this happen?” instead of, “Who’s fault is this?”. In this way, solutions and tools can be found to prevent the mistake from happening again. He advised listeners to introduce controls, use the patient’s dossier, think of solutions of possible problems beforehand, learn to say no, fight authority, use checklists, sterility, ergonomics, use clear wording and exchange! He mentioned an example of a rescue crew management programme at an academic medical centre that could reduce undesirable events by 25%.

Consideration on the patient’s biology was the topic of Sharham Ghanaati’s presentation. During surgical treatment, he said, the bone metabolism turns inactive and resorption at surgical site is induced. Furthermore, about 98% of biomaterials induce foreign body reaction, leading to uncontrolled degradation. Therefore, physiological and pathological reactions have to be differentiated. Big volume augmentation needs improved vascularization capacity and scientific history shows efforts on different factors, e.g. PRP, BMAC, PRGF, or PRF. A review on 15 years of experience with PRF was recently published, he mentioned, and he also highlighted vitamin D, which has been shown to influence bone metabolism significantly. Deficiency seems to be common throughout society and it is recommended to check vitamin D levels ahead of bone regenerative surgery, he advised as well.

Peri-implantitis: precaution and treatment

In the main programme on Saturday, the third day of the symposium, Frederic Duffau shed some light on the connection between periodontitis and peri-implantitis. He said that the presence of pockets increases the risk of peri-implantitis because the bacteria move around the mouth, and the bacteria that cause periodontitis and peri-implantitis are mostly the same. However, to remove all tooth and replace with only implants is also not a solution. He emphasised that it is very important to treat periodontitis first before an implant is placed, and that a healthy oral flora needs to be established. Healthy and sick mouths, he said, have a different bacteria composition, and there are less bacteria around implants than around teeth, but there is no difference between patients without teeth and partially edentulous.

Markus Schlee also talked about peri-implantitis, and in particular its treatment. Surgical goals, he said, are to remove the biofilm and to regain implant surface characteristics that allow reosseointegration of the implant. He presented the new GalvoSurge technique, which allows penetration of the biofilm in milliseconds, removes biofilms on non-integrated surfaces and renders them hydrophilic. In-vitro, complete removal of bacteria was proven, and pre-clinical histologies show reosseointegration after the treatment and GBR. A clinical controlled study on 24 patients is ongoing.

The programme was closed by Daniel Thoma with a presentation about the paradigm change in soft-tissue augmentation. Soft tissue deficits appear irrespective of implant timing or bone regeneration, he said. The literature indicates regular need for additional soft-tissue augmentation to improve aesthetics and peri-implant health. Soft-tissue grafting leads to less marginal bone loss and a volume gain of between 0.6 and 3.2 mm is reported, Thoma said, but usually an average of 1 - 1.5 mm can be expected. According to indications, alternatives to autologous transplants exist based on collagen matrices, e.g. for gain of keratinized tissue in open healing approach or volume gain in submerged healing approach. Clinical controlled studies on connective tissue graft (CTG) vs. xenogeneic collagen matrices have shown a similar volume gain, i.e. 1 -1.5 mm, but for the CTG, pain was three times higher and the overall morbidity even five times higher. He explained further that long term studies in controlled design cannot be performed for this indication, because the patients will receive crowns. Instead, long term observation to investigate volume changes are ongoing to get at least five-year data. Already available three-year data show only minor changes of -0.1 mm in both groups.

The chairmen, Franck Renouard and Philippe Russe, were very happy about the outcome of this congress and concluded at its closing on Saturday, “Thanks to all the people – sponsors, speakers and organisers –  that made this congress happen! We are looking forward to meet you again at the International Osteology Symposium from 2527 April 2019 in Barcelona.”