What Is Piezoelectric Bone Surgery?
More than three decades ago, for oral surgical procedures and implant drilling, PBS or piezoelectric bone surgery has proved a helpful surgical adjunct and substitute to surgeries with conventional electrical and mechanical instruments. More so, in the field of implant dentistry, this is a highly effective technique so that the risk of damage to the surrounding structures, tissues, mucosal layers, nerves, and blood vessels is reduced compared to conventional osteotomy hole preparation. It permits osteocyte proliferation during bone harvesting methods.
Initially used by maxillofacial surgeons only for osteotomies, recent advances have included PBS as part of orthopedic and neurosurgical procedures as well. Developed originally by maxillofacial surgeons, the radio waves that make the tip of the piezoelectric device (ultrasound tip) vibrate and oscillate with a cooling solution. The ultrasonic tip (vibrations with a frequency of 25-29 Khz), just like dental scalers, cause no tissue damage. In the case of the piezoelectric bone surgery tip, it has the ability to cut the mineralized bone tissue in a safe and sound manner with precision.
A piezoelectric device works similar to a dental scaler with a high frequency transmitted to the metallic tip with its force 3 to 6 times higher than the scaler tip used for a dental cleaning or scaling procedures. High precision that increases the preservation of neurologic and vascular structures and reduces hemorrhage (because of minimum damage by thermal source or heat to the bone) and improvement in the post-operative healing rate of the soft tissue makes PBS a trending advancement and innovation in the field of oral and maxillofacial surgery. As per research, PBS design is suited for operators, dental surgeons, or maxillofacial surgeons as the tip moves in a high-frequency motion following a linear reciprocal motion.
What Is the Need for Piezoelectric Bone Surgery?
The osseointegration phenomenon is influenced by the combined effects of implant characteristics (macro and micro geometry, biocompatibility) and the implant site preparation technique. Implant bed preparation is fundamental to achieve the ideal compromise between mechanical and biological features, providing adequate interlocking between the implant and surrounding bone.
Implant or osteotomy drilling procedures not only cause mechanical trauma but, if used without a coolant solution, can pose a threat of heat-induced necrosis leading to a significant factor that affects implant-bone osseointegration, healing, and bone remodeling. Though this fact cannot be directly proven, piezosurgery is preferred by some surgeons over conventional drilling protocols.
Studies, however, report no difference in the marginal bone level or implant failure rates when placing implants using a high insertion torque. In fact, early bone healing around implants is influenced by numerous variables, including patient-related factors (individual healing response, systemic disease, medication, smoking, bone density, and alveolar crest width) and surgical trauma related to site preparation (bone overheating, cortical compression, and damage to trabecular micro-architecture).
Excessive heat production during osteotomy preparation may be a leading cause of thermal necrosis and loss of bone cell proliferation and viability. Alternative techniques have been introduced to overcome the limitations of conventional drilling for implant site preparation, including osteotomies, erbium-doped yttrium aluminum garnet (Er: YAG) laser, osseodensification burs, and piezoelectric devices.
Piezoelectric devices modulate the ultrasonic vibration of an active tip and present three main advantages:
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Precise and controllable cutting.
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Selective action on mineralization tissues.
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Improved intra-operatory visibility due to cavitation of a cooling saline solution.
Furthermore, PBS enhances the bone healing response in the early post-surgical phase by promoting angiogenesis, reducing inflammation, and promoting a faster release of bone morphogenetic proteins.
When Is Piezoelectric Bone Surgery Indicated?
- Healthy patients.
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At least six months of healing after dental extraction.
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Both implant sites were inserted in similar bone quality.
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No grafted areas.
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The peak insertion torque is between 35 and 60 N-cm.
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Patients did not wear removable prostheses.
When Is Piezoelectric Surgery Not Recommended?
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Presence of relevant medical conditions.
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History of systemic disease contra-indicating surgical treatments.
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Systemic disease or the use of medication that potentially impairs surgery and bone healing dynamics.
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History of radiotherapy in head and neck region.
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Uncontrolled diabetes.
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Immunosuppressed or immunocompromised.
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Treated or under treatment with intravenous amino bisphosphonates.
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Smokers.
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Heavy smokers (>10 cigarettes/day).
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Pregnant or lactating women.
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Substance abusers.
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Patients with psychiatric problems or unrealistic expectations.
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Sites with acute infection.
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Active periodontitis and poor oral hygiene and motivation.
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Insufficient bone volume for implant insertion without augmentation procedures.
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Insufficient mesiodistal crestal space to properly insert two adjacent implants.
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Less than 2 mm buccal keratinized mucosa width and 3 mm mucosa thickness.
What Are the Benefits of Piezoelectric Bone Surgery?
Research has shown evidentially that piezosurgery may help promote the early expression of bone morphogenetic proteins and control the inflammatory process. The encouraging biological outcomes, together with the technological characteristics of piezoelectric cutting (micro-vibrations enhancing surgical control and selective action on mineralized tissues), paved the way for the clinical application of ultrasonic implant site preparation.
Ultrasonic Site Preparation vs. Conventional Site Preparation:
For implant site preparation, prolonged surgery duration, improved implant stability, reduced marginal bone loss, and enhanced survival rates in dental implants in comparison with conventional drilling techniques, the following conclusion can be drawn:
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There is insufficient data to assess if the ultrasonic implant site preparation reduces the marginal bone loss around the implant compared with conventional drilling techniques.
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There is insufficient data to assess if the ultrasonic implant site preparation improved the survival rate of dental implants compared with conventional drilling techniques.
Conclusion:
To conclude, piezoelectric bone surgery (PBS) has been proposed in this field to improve surgical control, safety, and bone healing response. However, despite the advantages of PBS for maxillofacial surgeons, insufficient evidence exists to prove by research that it is more productive than conventional implant drilling or conventional osteotomy procedures.
