18 April 2022

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Osseodensification and mandibular split crest: clinical case

Author: Marco Berardini

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It is general knowledge that the split crest technique allows predictable plastic de- formation of the bone and creates space for contextual insertion of osseointegrated dental implants. To this end, a clinical case of split crest surgery and contemporary implants insertion associated with the use of osseodensification burs in the anterior region of an edentulous mandibular area was proposed.

Materials and Methods
A 52 year old patient arrived to our observation to rehabilitate the mandibular anterior region where elements 3.1 and 4.1 were missing. A incision was created with a blade at the lingual-top of the crest and a total thickness flap was performed. A 10 mm deep (horizontal) osteotomic cut was performed with a piezoelectric scalpel mounting an insert of 0.35 mm thick. Subsequently, implant sites were prepared following the osseodensification surgical procedures and two 3x11 mm diameter laser-treated implants were inserted with a torque of 35 N. A resorbable collagen membrane and bovine bone were applied to protect the vestibular cortical. Antibiotic, anti-inflammatory therapy and a soft diet for 14 days were prescribed to the patient.

Results
After 4 months of submerged healing, the second surgical phase was performed for the positioning of the healing screws. The implants appeared osteointegrated and presented no clinical signs of inflammation or suffering of the hard and the soft tissues. A further confirmation of implants condition was obtained through x-ray examination. The keratinized tissue appeared stable.

Discussion
Prior to split crest surgery and osseodensification procedures, a pre-surgical diagnostic evaluation should be performed to en- sure that the two cortical are separable, with the presence of bone marrow, and not fused or even undercut. The surgical technique presented included a single surgical time in which the bone crest was incised longitudinally and progressively expanded with the aid of hydrodynamic pressure exerted by the burs used. The burs acted as osteocondensing osteotomes. Conversely to traditional rotating instrument for implants sites preparation, the employed burs work in a non-sharp anti-clockwise direction (between 800 and 1500 rpm). Thus, bone trabecules and collagen are “spread” on the bone walls instead of cut and removed. Such “autografting” bone involves the osteotomy site throughout its length forming a cylinder of increased density.

Conclusions
Split crest surgery showed predictable results in case of sufficient height but inadequate thickness of the bone. The use of the present osseodensification technique allowed controlled expansion and, at the same time, ensured excellent implant primary stability due to the local increase in bone density.

Clinical Significance
Implant-supported fixed rehabilitation represents the “gold standard” in the restorative rehabilitation of missed teeth. Vertical and horizontal bone remodeling due to teeth loss could make impossible to properly insert dental implants without hard or soft tissue augmentation. The split crest technique associated to osseodensification proved to be a predictable approach in the treatment to edentulous ridges of adequate height but insufficient thickness. High percentages of success, low incidence of com- plications and lower degree of morbidity for the patient make this type of intervention, preferable to GBR or graft blocks.