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Implant Tribune Asia Pacific Edition

Implant Tribune Asia Pacifi c Edition | 4/2017 TRENDS & APPLICATIONS XXXXXXX 23 temporary abutment also has a 1.5° Morse taper, which provides good friction retention and does not damage the cone in the implant. Before placing the temporary crown, I applied the bone obtained in the hollow drill shaft on the la- bial side and condensed it so that the alveolus was fi lled properly (Fig. 9). The temporary crown was shaped in such a way in the cervi- cal area that the alveolus was com- pletely covered. I checked that there was no functional stress (Fig. 10). At the follow-up a week later, good adaptation of the mu- cosa was already visible and the pa- tient reported no problems. After ten weeks, I removed the temporary crown and abutment. This is easy using crown removal pliers vertically. Using a pop-in im- pression coping, I took an impres- sion in a closed tray. The laboratory then made the permanent crown. The temporary crown with PEEK abutment was easily repositioned. In this case, I arranged for the crown to be returned from the lab- oratory separately from the abut- ment. The construction then had to be fi tted from the model of the mouth with a transfer key (Fig. 11a) because the structure is not in- dexed (therefore, it can be ce- mented in several ways because there is no internal indexing, such as a trilobe or internal hex). After fi tting the crown, which was ideal in both colour and shape, the structure was secured using the Safe Lock instrument (Anthogyr; Fig. 11b). This device is connected to the micromotor and produces short micro-strokes after activa- tion using the foot pedal. Five strokes is suffi cient to lock the abutment in place in the implant. The cold weld is then complete. I then cemented the crown accu- rately in the mouth with luting ce- ment. At the six-month (Fig. 12a) and 20-month (Figs. 12b & c) fol- low-ups, good adaptation of the mucosa was seen, and the results were considered to be good too. Case 2 The second patient approached me at the suggestion of a dental student who had read an interview about my fi rst experiences with narrow implants. The patient was no longer satisfi ed with the bonded bridge that replaced her tooth #22 owing to agenesis. She also found that the tissue increasingly ap- peared indented at that location (Fig. 13). The radiograph taken at the initial consultation showed sig- nifi cant convergence of the radices of teeth #21 and #23. The interden- tal space was 7.4 mm, but only 5.2 mm apically (Fig. 14). I approached this challenge with a 2.8 mm implant. I immedi- ately took an impression to make a temporary crown later. After I had removed the bonded bridge, I made a crestal sulcular incision, after which I tried to remove as lit- tle mucosa as possible. Again, I started by creating a guide with the osteotome (Nentwig), which al- lowed me to determine the posi- tion and direction. By using a slightly larger condenser, I very carefully pressed the labial wall down. As there was no large alveo- lus (no extraction had been done), applying autologous bone using the K-system was not necessary, and I only needed to use the con- densation technique. Again, the preparation was done to the cor- rect length using the 2.6 drill. I made a direct temporary crown on a PEEK abutment and paid much attention in the cervical area to creating the shape and a proper emergence profi le. In this case, an additional complication was that I had to convince the patient of the robustness and reliability of the temporary crown because of her six-month stay in Africa immedi- ately after seating of the tempo- rary crown on the implant. Based on my experience using this method for seven implants, I was able to reassure her. After six months, the patient returned to the practice and re- ported that she had not experi- enced any problems. I ob- served good adaptation of the mucosa (Fig. 15). After removing the temporary crown, which revealed an excellent emergence profi le with healthy mucosa, I made a pop-in impres- sion coping (Fig. 16). The laboratory again provided the structure with the separate crown. However, in this case, I decided to seat the crown as a whole after having fi tted it satisfactorily and bonded it out- side the mouth. This allowed me to avoid any embedding of cement residue (Fig. 19). However, I had to exercise greater care because I now had to tap the Safe Lock instru- ment directly on the zirconium di- oxide porcelain crown to secure the abutment. A special attach- ment is available for this, which allowed fi xture without any diffi - culties (Fig. 18). For this patient, I paid much attention to the cervi- cal gingival line. Tooth #12 was a cone tooth constructed with com- posite, and it was too small. I cor- rected the patient’s cervical gingi- val line satisfactorily with an elec- trotome and reconstructed tooth #12 with composite. This achieved a good result (Figs. 19–20b). Discussion and conclusion I inserted my fi rst 2.8 implant in 2013. Initially, I had some doubts about implants of such small di- ameter and had questions such as: Is the construction strong enough? Will it not break? Will the abut- ment–implant connection remain intact? However, although the use of such narrow implants remains a challenge, it has so far only yielded positive results. Nevertheless, I would like to make some remarks based on my experiences: 1. All of the major brand implant systems marketing narrow im- plants have paid much attention to the root shape of the implant with threads that have a condensing ef- fect. This signifi cantly increases the primary stability, which en- hances osseointegration. 14 15 16 18 17 19 20a Fig. 14: Radiograph of the initial situ- ation.—Fig. 15: Clinical image after six months with a temporary solu- tion.—Fig. 16: Insertion of a pop-in impression coping after removal of the temporary crown.—Fig. 17: Bond- ing of the permanent crown.—Fig. 18: The Safe Lock instrument with tips.— Fig. 19: Clinical image immediately after insertion of the permanent crown and adjustment of the gingival line.—Fig. 20a & b: (a) Radiograph and (b) clinical image three months after inserting the crown. the strength). However, these are so narrow that there is enough body for the crown to make the restora- tion aesthetically pleasing. The use of a narrow implant in a very limited space requires a well thought-out diagnosis, great preci- sion of work, and good use of and experience with different implant techniques. These cases were not treated using any guided surgery, but this could be recommended for precise implant positioning. Editorial note: This article was fi rst published in implants—international magazine of oral implantology, Issue 4/16. Dr Huub van’t Veld has over 40 years of experience as a dentist and is certifi ed as implan- an tologist by the Dutch Association of Oral Im- plantology. He can be contacted at 20b 2. This primary stability also re- sults in greater usability in imme- diate placement and provides the option of seating a temporary crown immediately. 3. The PEEK abutment used in this system has been proven to allow trouble-free retention over a longer time. Because in these cases, the im- plant was placed subcrestally and despite the small space, there was still enough surrounding bone, I ob- served good support of the mucosa and the presence of a good mucosal seal. In these cases, a 2.8 mm plat- form was used as a superstructure with a platform switch. As a result, a proper emergence profi le was achieved with the temporary crown. 4. Particularly with regard to re- duced mesiodistal spaces, the use of an implant with a small diameter is a solution, but only in the aesthetic zone, where no extreme transverse stress will be placed on the implant. 5. I believe that with excessive stress and great forces, because the implant is so narrow, the abut- ment–implant connection could be a limiting factor. 6. The facio-lingual bone thickness is less restrictive in the application of a small-diameter implant because with several techniques, such as bone splitting and harvested autolo- gous bone with the K-system or pos- sibly with a bone graft, more volume can be created in a less invasive way. 7. In order to achieve a good result, it is necessary for the practitioner to have the choice of various abut- ments. Therefore, one of the two- piece implant systems should be chosen. A narrow one-piece implant is less suitable for the aesthetic zone. 8. The solid connection between abutment and implant with the Morse taper connection is indeed strong and poses no risk of screw fracture, but there is no return. The implant becomes a one-piece im- plant with the solid abutment. By using Grade 5 titanium, strength is assured: extensive stress tests have been carried out up to 200 N. The positioning and permanent fi xing of the restoration do require more attention than with a screwed abut- ment. For instance, a break in the crown may only be repaired by using the abutment for a new im- pression of the crown stump. It is unfortunate that only titanium abutments are available (owing to

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