Importance of 5.5 mm Implant
Pre-op exam shows that there is mild to moderate buccal and lingual atrophy at the site of #19. After raising the flaps, use of a 5 mm implant positioner reveals that the ridge can hold a 5 mm implant. Initial osteotomy depth is 11.5 mm (Fig.1); there is more than 5 mm distance from the superior border of the Inferior Alveolar Canal (red dashed line in the lower right corner). The depth is adjusted to 13 mm. When a 5x13 mm drill is in place, there appears to be extra space to a larger implant (5.5 mm or 6 mm). The patient seems to be a bruxer. The dilemma is that there is no corresponding drill for the 5.5 mm implant. When a 6x12 mm drill is used, the buccal plate is thin. Fortunately a 6x12 mm implant is placed with insertion torque > 55 Ncm (Fig.2,3). Autogenous bone harvested with drills at 55 RPM is placed around the coronal portion of the implant, mainly buccally and lingually after placement of a 7.5x4(3) mm cemented abutment (data not shown). An immediate provisional is fabricated after suturing. Periodontal dressing is applied to cover the remaining wound. Probably due to the full protection from the provisional and periodontal dressing, there is no postop pain.
There is mild crestal bone resorption 3.5 months postop (Fig.4 arrowhead). After the abutment is torqued at 35 Ncm, impression is taken for final restoration.
Return to Lower Molar Immediate Implant,
Posterior Immediate Provisional,
Xin Wei, DDS, PhD, MS 1st edition 08/31/2015, last revision 12/16/2015