A new approach for patients on direct oral anti-coagulant medication

Implant placement is a surgical procedure employed in accordance with the individual wishes of patients. It can often be avoided by choosing conventional, non-surgical alternatives. In particular, in cases of patients with haem-orrhagic diathesis or patients undergoing anti-coagulant therapy with direct oral anti-coagulants (DOACs), the risk of undesired side effects, with even life-endangering consequences, necessarily led to a strict selection of patients who are suitable for dental implants. A new laser-supported approach in implantology for patients under-going anti-coagulant therapy has been developed by the Aachen Institute for Continuous Medical and Dental Education in cooperation with the Clinic for Cardiology, Pneumology, Angiology and Internal Intensive Medicine of the RWTH Aachen University hospital in Germany.

Case presentation

Nowadays, the number of implants placed in patients with a higher average age and in medically compromised cases is rising. Particularly cases of patients undergoing DOAC therapy, with the advantage of no need to perma-nently control the coagulation parameters, are rising sig-nifcantly. Despite the advice of cardiologists not to stop or interrupt the medication, these patients often request implants. In addition, for only two DOACs does an an-tagonist drug exist. For three other DOACs, there is no antagonist drug yet, leading to an increase in possible postoperative complications. Nevertheless, among this group of patients, the demand for implants is rising as well. To fulfl these wishes while following the advice of the cardiologist, a new transgingival, nearly blood-free surgi-cal protocol has been developed. The following case de-scribes this procedure in general and points out differ-ences in relation to conventional treatment. Clinical and radiographic situation A 62-year-old male patient with moderate general health attended the prosthetic consultation. His medical his-tory revealed that he had had three bypasses between 2014 and 2016 and signs of anginal attacks. Also, there were periodically recurring events of sinus arrhythmias. For a duration of three years, he had been on dabig-atran etexilate (Pradaxa), which is a direct thrombin inhibitor. He was slightly overweight and a non-smoker. Upon intra-oral examination, restoratively and prostheti-cally rehabilitated dentition and missing teeth #14, 27 and 35 were noted, and it was observed that position #14 had reduced in size (Fig. 1). The patient maintained good oral hygiene. The panoramic radiograph revealed an apically compromised tooth #47 with furcation involvement and good bone structure in positions #14 and 35 (Figs. 2 & b). The patient was thoroughly informed regarding the treat-ment options. He asked for an implant replacement for tooth #14 and possibly, at a later stage, for tooth #35. After an explanation about the medical compromises regarding a surgical intervention and after consulting the cardiologist regarding the DOAC therapy, it was mutually decided not to interrupt medication with Pradaxa and to opt for trans-gingival, laser-supported implant surgery in position #14. The initial bone contours showed a suffcient amount of bone in all three dimensions. If the bone width appears critical, a 3D radiograph is highly recommended to evalu-ate the amount of bone in the third dimension.

Fig. 1: The reduced size of position #14.

Figs. 2a & b: Dental panoramic tomogram (a) and periapical radiograph (b) prior to implant placement.

Laser treatment and implant insertion

After local anaesthesia, the initial osteotomy for the im-plant was performed with a pilot drill (locator drill; Fig. 3). A guide for a conventional rotating soft-tissue punch with a central guide pin that matched the pilot drill hole was placed in situ as an outline guide for the blood-free laser punch procedure (Figs. 4a & b). The laser unit used was an Er,Cr:YSGG laser operating at a wavelength of 2,780nm (Waterlase iPlus, BIOLASE). The laser was set to the parameters shown in Figure 5.

Fig. 3: The initial osteotomy for the implant being performed with the pilot drill.

Figs. 4a & b: The guide for a conventional rotating soft-tissue punch with a central guide pin matching the pilot drill hole (a). The laser handpiece used (b).

After the laser incision, the punched tissue was removed with a curette (Figs. 6a & b). Thereafter, following the drill protocol of the implant sys-tem placed, a ProActive Tapered implant of 4mm in diameter and 13mm in length (Neoss) was inserted to a 32 Ncm torque (Figs. 7 & 8).

Figs. 6a & b: Removal of the punched tissue with a curette (a). The tissue removed with the punch (b).

Fig. 8: Periapical radiograph immediately after implant insertion.

The healing abutment was inserted to 15 Ncm. Slight pressure on the surrounding tissue is important, for which the diameter of the healing abutment should be at least 1mm larger than the punch diameter. In this case, the tissue punch diameter was 4.3mm and the healing abutment was 5.5 mm in diame-ter (Fig. 9). The defnitive restoration is shown in Figure 10.

Fig. 9: Slight anaemia was visible around the healing abutment, demonstrating the pressure on the surrounding tissue required to prevent post-op haemorrhage.

Discussion

After three months of healing, the implant can be loaded and the superstructure can be installed. Following the protocol described, 143 implants have been inserted during the last three years. The retrospective analysis of this method showed postoperative haemorrhage with the need for additional intervention for ten of these. Seven of the ten appeared during the frst 30 implantations. After fnding the right relation between size of the tissue punch and size of the healing abutment (diameter and height), only three cases of postoperative haemorrhage were en-countered. The main precondition for this kind of treat-ment is a suffcient amount of bone in the implant site. Any augmentative procedures more demanding than a punch technique to gain 1–2mm in the neck area of the implant are not compatible with the protocol described. In cases of reduced horizontal bone volume, case suit-ability for the laser-supported protocol should be eval-uated by 3D radiography. The postoperative evaluation by the Clinic for Cardiology, Pneumology, Angiology and Internal Intensive Medicine showed no negative effects on the general health of the patients treated. This protocol is offcially recommended by the clinic.

Conclusion

The use of laser in this delicate zone of soft tissue and bone of the implant site is very benefcial and does not harm the bone (or soft tissue) through high temperatures or carbonisation. In addition, the positive effect of biostim-ulation leads to quicker and better healing by accelerating the fbroblast activity around the implant. Of course, the primary beneft for patients is the reduction of the general risk of blood clotting and thrombosis, which can possibly cause seizures or strokes during the interruption of anti-coagulant therapy, and such interruption is no longer essential with this laser-supported protocol.