Risks and complications

The risk patient


Chairs: Henning Schliephake (Germany) and Ulrike Webersberger (Austria)

More and more medically compromised patients are coming to our offices looking for tooth replacements. This is because the world’s population is getting older, and the ageing demographic brings with it more risks such as (Figure 1):

  • cardiovascular conditions
  • bleeding due to more and more people receiving anticoagulant prescriptions
  • wound-healing disorders associated with diabetes
  • impaired immune function tissue necrosis induced by anti-osteoporotic medication

It is now more important than ever to stay up-to-date in the field of implant dentistry and in medical aspects related to the field.

“The ageing demographic brings with it more risks”

The chairs described a 65-year-old patient whose situation seemed relatively straightforward at first (Figure 2). However, following extraction and periodontal therapy, it was discovered that the patient was receiving corticosteroids to treat a chronic autoimmune disease and had developed secondary osteoporosis. Further investigation revealed that the patient was also receiving bisphosphonates. These risk factors combined to make a ‘Catch 22’ situation: implants could not be placed and nor could a mucosa-borne. As a result, the patient was classed as a ‘risk patient’.

“It is now more important than ever to stay up-to-date in the field of implant dentistry”

The chairs also described a second patient who presented with peri-implantitis (Figure 3). The patient was also taking novel oral anticoagulants, which further complicated their case. The question the chairs asked was: what are we going to do with medically compromised patients like this?

Presentation figures

Figure 1

Figure 2

Figure 3

Novel oral anticoagulants and risk

Stephan Acham (Austria)

Direct oral anticoagulants (DOAC) are commonly used to treat venous thromboembolism. The main DOACs can be categorised as factor Xa inhibitors: rivaroxaban (Xarelto®), apixaban (Eliquis®), edoxaban (Lixiana®); or as direct thrombin IIa inhibitors: dabigatran (Pradaxa®).

DOACs have obvious pharmacological advantages, such as: predictable and consistent anticoagulant effects, rapid onset/offset of action and low interactions. They have replaced Vitamin K antagonists (VKA) and coumarin anticoagulants in thromboembolic prevention, especially in cases involving atrial fibrillation.

However, DOACs do have associated risks (Shi et al. 2017; Clemm et al. 2016; Yagyuu et al. 2017). Since DOACs started being prescribed widely, an increasing number of bleeding events have been registered in the European database of suspected adverse drug reaction reports. Compared to VKAs, however, DOACs have a lower postoperative risk following implant surgery. Additionally, there is less risk of bleeding associated with implant surgery than with extractions.

“DOACs have obvious pharmacological advantages … However, DOACs do have associated risks”

In order to assess the risk of bleeding events, we should focus on plasma levels following dosage. Plasma concentration levels peak 2–3 hours after the last intake of the medication, and drop to trough levels about 16–24 hours after. This is the period when surgery would be safer.

“Surgery would be safer 16–24 hours after medication intake”

Dabigatran (Pradaxa®) and rivaroxaban (Xarelto®) have especially high renal elimination (over 80% and 60% respectively). But when renal function is impaired, the elimination of DOACs decreases significantly. The maximum plasma level is higher, and trough levels are not reached until around 48 hours later.

“When renal function is impaired, the elimination of DOACs decreases significantly”

The speaker described the ORBIT bleeding score, which is a five-element index validated for assessing the individual bleeding risk of DOACs and for supporting clinical decision making (O’Brien et al. 2015). The ORBIT scoring system includes the following risk contributors, along with their associated score (O’Brien et al. 2015):

  • old age (over 75 years of age) [1]
  • reduced haemoglobin (Hb) or haematocrit (Hct) or anaemia [2]
  • bleeding history [2]
  • insufficient kidney function [1]
  • treatment with antiplatelets [1]

The higher the score the higher the bleeding risk; the maximum score is 7.

“The higher the score the higher the bleeding risk”

Bleeding risks and preoperative haemostatic control measures are only supported by scientific evidence type III (clinical experience). The current protocol for managing bleeding risks includes careful patient selection and taking appropriate measures according to the expected surgical morbidity (Lanau et al. 2017). The speaker stated that the prevention of bleeding risks involves three elements: invasiveness; anatomical site; medical necessity. The speaker outlined the following factors which should be taken into account to assess risk:

  • patient selection: when selecting patients, we should exercise caution with elderly and multimorbid patients, or those with hypertension, a history of bleeding, anaemia, renal impairment, or diabetes
  • the pharmacologic risk: drugs influencing the DOAC’s effects, such as: NSAIDs and Azole antimycotics etc. (Forbes & Polasek. 2017). In general, drug interactions are lower, compared with VKAs
  • invasiveness of procedure: in simpler and less invasive surgical procedures, it is advisable to keep a minimum time interval (12–24h) between the last dose and the surgical intervention (type II) and to maximise local haemostatic measures (type I)
  • discontinuation: in complex surgeries temporary suspension of DOACs may be indicated, but always only having consulted an internist (type I)
  • antagonists: antagonists to DOACs are available to stop severe haemorrhages (type II)

Clemm R, Neukam FW, Rusche B, Bauersachs A, Musazada S, Schmitt CM. Management of anticoagulated patients in implant therapy: a clinical comparative study. Clin Oral Implants Res. 2016 Oct;27(10):1274-1282. doi: 10.1111/clr.12732. Epub 2015 Nov 23.

Forbes HL, Polasek TM. Potential drug-drug interactions with direct oral anticoagulants in elderly hospitalized patients. Ther Adv Drug Saf. 2017 Oct;8(10):319-328. doi: 10.1177/2042098617719815. Epub 2017 Jul 11.

Lanau N, Mareque J, Giner L, Zabalza M. Direct oral anticoagulants and its implications in dentistry. A review of literature. J Clin Exp Dent. 2017 Nov 1;9(11):e1346-e1354. doi: 10.4317/jced.54004. eCollection 2017 Nov.

O’Brien EC, Simon DN, Thomas LE, Hylek EM, Gersh BJ, Ansell JE, Kowey PR, Mahaffey KW, Chang P, Fonarow GC, Pencina MJ, Piccini JP, Peterson ED. The ORBIT bleeding score: a simple bedside score to assess bleeding risk in atrial fibrillation. Eur Heart J. 2015 Dec 7;36(46):3258-64. doi: 10.1093/eurheartj/ehv476. Epub 2015 Sep 29.

Shi Q, Xu J, Zhang T, Zhang B, Liu H. Post-operative Bleeding Risk in Dental Surgery for Patients on Oral Anticoagulant Therapy: A Meta-analysis of Observational Studies. Front Pharmacol. 2017 Feb 8;8:58. doi: 10.3389/fphar.2017.00058. eCollection 2017.

Yagyuu T, Kawakami M, Ueyama Y, Imada M, Kurihara M, Matsusue Y, Imai Y, Yamamoto K, Kirita T. Risks of postextraction bleeding after receiving direct oral anticoagulants or warfarin: a retrospective cohort study. BMJ Open. 2017 Aug 21;7(8):e015952. doi: 10.1136/bmjopen-2017-015952.

Anti-resorptive drug therapy and risk

Morten Schiødt (Denmark)

Anti-resorptive drugs (ARDs) – such as bisphosphonates (BPs) and denosumab – are widely used to treat osteoporosis, because they help reduce pain and spontaneous fractures, and control bone metastases.

“Anti-resorptive drugs (ARDs) are widely used to treat osteoporosis”

There are three groups of ARDs: low dose used in osteoporosis; high dose used in cancer patients with metastases; and a new group of intermediate dose used as ‘adjuvant therapy’ in cancer patients without metastases (to decrease the risk of the cancer recurring).

Potential risks of dead bone and implant loss are related to dose and duration, not to the method by which the drugs are administered.

The most recent data for ARDs come from the EAO Consensus in 2018 (Schliephake et al. 2018). It was concluded that:

  • patients receiving oral low-dose ARD do not have an increased risk of implant loss
  • both low- and high-dose ARD patients are at risk of developing MRONJ irrespective of whether they undergo implant therapy. This risk increases with dose and duration of ARD intake
  • the incidence of implant-associated MRONJ in low-dose ARD patients is unknown, either in cases involving oral, subcutaneous or intravenous administration
  • the supposed benefits of ‘drug holidays’ are still unclear

“Both low- and high-dose ARD patients are at risk of developing MRONJ”

Some clinical recommendations were also drawn:

  • in patients receiving low-dose denosumab or oral BP, implants can be placed as safely as in other patients with osteoporosis
  • there is no data on low-dose subcutaneous and intravenous ARDs, but these are not expected to a have a higher risk than oral low-dose ARDs
  • prophylactic antibiotics are recommended
  • the patient’s risk factors should be evaluated individually: smoking, oral hygiene, local pathology, systemic co-factors, etc.
  • implant therapy and bone grafting are currently not indicated in high-dose ARD patients
  • five years of oral BP intake may be a ‘red flag’ for potential risks

Presentation figures

Figure 1

Figure 2


Schliephake H, Sicilia A, Nawas BA, Donos N, Gruber R, Jepsen S, Milinkovic I, Mombelli A, Navarro JM, Quirynen M, Rocchietta I, Schiødt M, Schou S, Stähli A, Stavropoulos A. Drugs and diseases: Summary and consensus statements of group 1. The 5th EAO Consensus Conference 2018. Clin Oral Implants Res. 2018 Oct;29 Suppl 18:93-99. doi: 10.1111/clr.13270.

Managing patient expectations from implant therapy: new strategies for an old risk!

Nikos Mattheos (China)

Treatment success can be thoroughly evaluated, and there are a number of different parameters for measuring tissue integration, tissue health, function and aesthetics. The patient’s perception may differ from our clinical perspective.

“The patient’s perception may differ from our clinical perspective”

Patients may be looking to get back something they had lost or to get something which they never had before; or they may be looking for an improvement to their quality of life, which is a multifaceted concept and should be highly individualised. Whatever their original motivation is, their satisfaction with the final result and treatment outcomes will be greatly influenced by their expectations (Allen & McMillan. 2003).

“The patient’s satisfaction is highly dependent on their previous expectations”

Expectations are continuously forming in our mind and are part of the decision-making process (Bowling et al. 2012). In 2014, Yao et al. carried out a systematic review to identify the factors influencing the process of forming expectations about dental treatment outcomes. In addition to personal characteristics, social environment and previous experiences with dental treatment (which are innate to the patient), there are some factors which the dentist can alter or modify, such as: knowledge, attitudes, values and beliefs (Yao et al. 2014).

For a thorough diagnosis, the chief complaint together with medical and dental histories should be taken into consideration, and an assessment of the patient’s perceptions and expectations should be carried out.

A considerable number of patients have misconceptions. Apart from their dentist, their main source of information about treatment comes from their social environment or the internet (Yao et al. 2017). In 2017, the educational value of YouTube and its potential for misleading statements was investigated. Its contents were analysed and compared to the EAO’s patient information booklet (Ho et al. 2017).

“A considerable number of patients have misconceptions.”

Of the 270 videos which were analysed, less than 0.5% had genuine patient testimonials. References to complications or negative results were lacking, references to patient selection were minimal and there were a number of statements made which were potentially (and even dangerously) misleading.

Dentists are still reluctant to discuss the life expectancy of implants with the patient or predict their longevity (Kashbour et al. 2018). This issue still remains controversial due to the many factors which may influence the clinical evolution of implant reconstructions over the years.

Altered expectations of patients were also studied in cases involving peri-implantitis, and the authors found unrealistically high expectations around implant therapy (Abrahamsson et al. 2017). In these cases, it was shown that patients with unrealistic expectations are not capable of coping with the problem and as a consequence they do not understand why they have to pay more for the treatment, so they lose trust in their dentists and show ambivalence towards implants in the future.

“Patients with unrealistic expectations … lose trust in their dentists and show ambivalence towards implants”

As a conclusion, we shouldn’t keep on relying on a simple equation of: patient’s complaint — implant treatment — objective: successful outcome’ (Figure 1).

During the diagnostic phase, the patients’ expectations should be assessed, based on a number of psychosocial and biographic factors. We should try to guide these expectations along the treatment process to finally reach not only an objective for success, but a satisfactory outcome as well.

Presentation figures

Figure 1


Abrahamsson KH, Wennström JL, Berglundh T, Abrahamsson I. Altered expectations on dental implant therapy; views of patients referred for treatment of peri-implantitis. Clin Oral Implants Res. 2017 Apr;28(4):437-442. doi: 10.1111/clr.12817. Epub 2016 Feb 25.

Allen PF, McMillan AS. A longitudinal study of quality of life outcomes in older adults requesting implant prostheses and complete removable dentures. Clin Oral Implants Res. 2003 Apr;14(2):173-9.

Bowling A, Rowe G, Lambert N, Waddington M, Mahtani KR, Kenten C, Howe A, Francis SA. The measurement of patients’ expectations for health care: a review and psychometric testing of a measure of patients’ expectations. Health Technol Assess. 2012 Jul;16(30):i-xii, 1-509. doi: 10.3310/hta16300.

Ho A, McGrath C, Mattheos N. Social media patient testimonials in implant dentistry: information or misinformation? Clin Oral Implants Res. 2017 Jul;28(7):791-800. doi: 10.1111/clr.12883. Epub 2016 Jun 8.

Kashbour WA, Rousseau NS, Thomason JM, Ellis JS. Provision of information to patients on dental implant treatment: Clinicians’ perspectives on the current approaches and future strategies. J Dent. 2018 Sep;76:117-124. doi: 10.1016/j.jdent.2018.07.002. Epub 2018 Jul 9.

Yao J, Tang H, Gao XL, McGrath C, Mattheos N. Patients’ expectations to dental implant: a systematic review of the literature. Health Qual Life Outcomes. 2014 Oct 29;12:153. doi: 10.1186/s12955-014-0153-9.

Yao J, Li M, Tang H, Wang PL, Zhao YX, McGrath C, Mattheos N. What do patients expect from treatment with Dental Implants? Perceptions, expectations and misconceptions: a multicenter study. Clin Oral Implants Res. 2017 Mar;28(3):261-271. doi: 10.1111/clr.12793. Epub 2016 Mar 23.


Session speakers

Speaking of anticoagulants, a good piece of advice would be to advise the patient to take their medication in the evening (instead of in the morning) so the maximum effect of the anticoagulants would be at night and surgery can be performed during the day, within the ‘safe window’ of time.

“Always try to minimise the invasiveness of surgical procedures.”

In cases involving multiple extractions and a patient presenting with risk factors, it is prudent to proceed with a staged approach. Always try to minimise the invasiveness of surgical procedures.

The risk of MRONJ in patients taking ARDs relates mainly to either post-extraction infection, interruption of soft tissue coverage or even peri-implantitis. Some patients with MRONJ have healthy implants and do not encounter problems with them.

How can patients who are prone to misconceptions be identified? This can be done during the initial diagnosis. Patients who seem to be sceptical, ask lots of questions, and look for a second opinion are not difficult to deal with. They are expressing themselves and are eager to get information about their treatment; they are open to communication and we can have a discussion with them. Patients who remain silent, and are reluctant to engage in discussion are the main concern, as they tend to try to put all the responsibility in your hands and do not want to participate in the treatment decisions.

“Patients who remain silent, and are reluctant to engage in discussion are the main concern”

Face-to-face communication between the doctor and patient is the ultimate tool for resolving treatment misconceptions. We can give patients the appropriate information to dispel any misinformation or misconceptions (for example the EAO patient information booklet). We can then can spend time discussing any questions which the brochure has raised for them. Usually, the patient can understand general information, or ‘the basics’, but they cannot apply it to their particular case. This is our task.

“Face-to-face communication between the doctor and patient is the ultimate tool for resolving treatment misconceptions.”

The more complex and extensive the treatment, the more challenging it is to communicate it to the patient and help them come to a realistic expectation. A questionnaire at the beginning of the diagnostic phase can help us investigate patients’ misconceptions and give us an opportunity to make them better understand the treatment details.

Take-home messages

In patients taking DOACs, a good piece of advice is to schedule surgery in the morning and delay drug intake until the evening.

In patients taking low-dose ARDs, implants can be placed when the duration of drug intake is under five years. Patients taking high-dose ARD treatment and who already have implants should be strictly monitored to prevent peri-implant inflammation.

To prevent misconceptions leading to a lack of satisfaction with treatment outcomes, patient expectations should be checked during the diagnostic phase. This is when appropriate information should be provided to and discussed with the patient. Although many methods are available and can contribute to effective communication, it appears that the role of face-to-face interaction is still irreplaceable.