Why Is Bone Mineral Density Assessment Essential for Dental Implantation?
Patients widely prefer dental implants in terms of both function and esthetics; by both edentulous and otherwise. In addition, dental implantation offers the patient added advantages like preserving the remaining teeth and enhancing masticatory movements.There is an increase in the use of dental implants over the last decade because of the long-term treatment outcomes that are favorable to the patient. And because of good patient compliance with regular dental follow-ups and oral hygiene maintenance.
The crucial factor that enhances favorable long-term outcomes for dental implants is bone mineral density (BMD). The nature or quality of the bone, be it in the maxillary or mandibular region to be implanted, is preoperatively assessed by the implantologist. Assessment technique includes simple intraoral radiography to use CBCT (cone beam computed tomography) for detailed planning or through dual X-ray absorptiometry. A common technique used to preserve the bone or maintain bone quality in recent decades is the osseodensification technique of dental implantation, which a few clinicians prefer over conventional implant drilling protocols.
What Are the Benefits of Osseodensification?
Osseodensification is similar to the conventional dental implant technique except for using specialized burs in this method. Apart from this, it can facilitate more bulk of the bone and cause bone deformation or, in other words, enhance the outward strain on the trabecular bone resulting in alveolar ridge expansion (that is otherwise not possible with conventional implant drilling protocols). This technique also facilitates compaction autografting and ridge expansion, as mentioned above, which are currently novel osteotomy preparation methods. The challenges with the region of implantation in edentulous patients are that despite good healing, atraumatic extraction methods, or even the use of ridge preservation procedures.
Most edentulous patients need additional augmentation procedures in the region of dental implant for gaining the bulk or bone volume in the area. Osseodensification hence eliminates the potential need and offers an advantage to the operator and the patient by reducing chair time during implant drilling by using osseodensification burs (specialized set of burs that are used in a counterclockwise direction). This effects in controlled plastic deformation of the bone drilled and producing rather an elastic rebound phenomenon. This rebound effect of the bone would be responsible for early bone-implant fusion and faster healing.
How Does Compaction Autograft Help to Gain Bone Bulk?
Compaction autografting is an added advantage wherein the grafted bone particles would be firmly held against the implant resulting in the improvisation of primary implant stability throughout the osseointegration phase (bone-to-implant fusion phase). Furthermore, due to the counterclockwise motion of the burs used in this technique, when fragments of autogenous bone graft are pushed apart, they will be in the apical and lateral directions. And that tends to increase the primary stability. This is a nucleation center for the new and vital bone to form during the early phases of osseointegration.
Apart from primary stability, additional bone volume can be gained because of the autografted particles during the insertion of the implant. Subsequently, the rationale behind the success of compaction autografting is that the elastic rebound or spring back phenomenon will occur within the internal walls of the compact bone. The reduction in the number of surgical steps with osseodensification, unlike the conventional implant osteotomy preparation accompanied by additional GBR-guided bone regeneration procedures or accessory bone augmentation procedures, would be beneficial to the implantologist in terms of the use of the technique.
What Is the Procedure of Osseodensification Facilitated Ridge Expansion?
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The flap is elevated at the site of osteotomy preparation before starting the drilling protocol. The implant dentist would measure the alveolar ridge with standardized bone calipers at the level of the bone crest.
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A 1.5 mm (millimeter) osteotomy pilot drill is used to start the preparation, followed by the specialized reverse cutting osseodensification burs at a rotation speed of 900 to 1200 RPM (rotations per minute) increasing the width increments.
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The surgeon or implant dentist should repeat the alveolar ridge measurements post the osteotomy preparation. Then the implant head diameter should ideally be equal to or wider than the measured ridge width.
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The implant stability always needs assessment by the operator as the insertion torque given by the dentist plays a pivotal role in maintaining primary stability. Some clinicians also use the advanced resonance frequency analysis system that measures the ISQ (implant stability quotient) value of the dental implant placed.
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Based on the clinical perception or judgment of the dental operator, additional procedures can be performed post-dental implantation, like gaining the buccal bone thickness through hard or soft tissue grafting and a one-stage or two-stage treatment plan.
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A major factor that needs to be considered by the dentist is the density or the thickness of the cortical bone layer. When the cortical bone is thinner with dense trabecular bone, then the rate of plastic deformation would be higher. The risk is that when the trabecular bone is of low volume, it is more likely to undergo microfractures through the osseodensification ridge expansion technique because it will not undergo plastic deformation as such.
Conclusion
To conclude, the implantologist should have an accurate diagnosis and treatment plan apart from considering the crucial factors such as bone volume, structure, and composition, as well as the personal clinical judgment of surgical protocols for using this technique of osseodensification, facilitated alveolar ridge expansion to favor long term implant stability and favorable prognosis outcomes.
