GAP Australasian-Dentist-May June 2019

Category AustrAlAsiAn Dentist 31 possible replacement of the maxillary left central incisor and evaluate at an advanced stage with a temporary crown on the implant and mature, conditioned tissue whether to add a veneer to the maxillary right central incisor. Analysing the CBCT scan it became evident that the short-rooted tooth could be extracted without compromising the buccal bone, and that there was sufficient bone volume and quality to obtain good primary stability of the implant. thanks to the Ais 3D App software, this information can be visualised using the bone density tool and linear measures tool (Fig. 10c) and represented in a graphic or according to a coloured scale. the presence of the nasopalatine duct prohibited ideal palatal positioning of the implant, and if the implant were to be placed flush with the palatal alveolar bone, this would have resulted in a 1.5–2.0mm high exposure of the implant collar on the buccal aspect (Fig. 11a). this information, combined with the aesthetic analysis, led to the decision to place the implant in that position and to augment the buccal bone volume with a contemporaneous GBr procedure, thus also providing for major soft tissue support. As often described in the literature, it is to be expected that in some measure the implant will deviate buccally 2–4 from the original planning because of the major mechanical resistance of the palatal plate. the author’s team prefers whenever possible screw-retained solutions. several production centres are capable of milling angulated screw access holes in cobalt- chromium abutments of up to 25°, 5 which is a range that covers most cases in daily practice. it can be easily checked in the implant planning software whether the future access hole will exit on the palatal aspect of the tooth, either by angulating the implant extension tool or by choosing a virtual abutment from the library. Confirming being in the safety range from this point of view allowed for an approach that foresaw the implant in native bone without the necessity for major GBr on the apical aspect of the implant. Knowing that a flap needed to be raised to facilitate the marginal tissue augmentation, it was decided to use a surgical guide (Figs. 11a & b) for only the first drill to determine with precision the position and angulation of the osteotomy that would be performed freehand thereafter. in order to limit surgery time and eliminate unpredictable factors inherent in immediate loading, a removable temporary prosthetic tooth was produced in advance. Surgery local anaesthesia was performed with 2% mepivacaine with 1:100,000 adrenaline. Preventative antibiotic therapy with amoxicillin (1g, b.d. for five days) was prescribed, aided by use of a 0.2% chlorhexidine mouthrinse three times a day for one minute. the tooth was extracted and the sulcular epithelium removed with diamond burs. the milled surgical template (Figs. 12 & 13) served as a guide for the first 2mm diameter pilot drill (Fig. 14). thus, the planned depth, position and angulation of the osteotomy were obtained. the drill sequence was completed freehand, using tapered 3.0 and 3.4mm drills. A neoss ProActive tapered implant of 4mm in diameter and 13mm in length was inserted flush with the mesial/palatal/distal bone, motor driven up to a torque of 50ncm and then with a manual wrench (Fig. 15). the correct position of the internal hex was verified by checking the references on the implant driver, which ideally points in the buccal direction. resonance frequency analysis with Penguin rFA (integration Diagnostics sweden) determined an isQ value of 73/76. At this stage, a neoss Aesthetic Healing Abutment with a scanPeg was connected to the implant lInICal Fig 22 Fig 23 Fig 24 Fig 25 Fig 26