|Year : 2021 | Volume
| Issue : 2 | Page : 40-42
Tackling bone density through different osteotomy preparation techniques
Amol Ashok Dubey1, Parmeet Singh Banga2, Saumil Sampat3
1 Consultant, MDS Department of Oral and Maxillofacial Surgery, Baba Jeevan Singhji memorial Medical Center, Gurudwara Shree Dashmesh Darbar, Gurutech Bahadur Nagar, Navi Mumbai, Maharashtra, India
2 MDS (Prosthodontics Crowns and Bridges), Prof, Department of Prosthodontics, G. D. Pol Dental College and Research Center, Navi Mumbai, Maharashtra, India
3 MDS (Prosthodontics Crowns and Bridges), Senior Lecturer, Department of prosthodontics, G. D. Pol Dental College and Research Center, Navi Mumbai, Maharashtra, India
|Date of Submission||04-May-2021|
|Date of Acceptance||24-May-2021|
|Date of Web Publication||22-Sep-2021|
Dr. Amol Ashok Dubey
Consultant, MDS Department of Oral and Maxillofacial Surgery, Baba Jeevan Singhji memorial Medical Center, Gurudwara Shree Dashmesh Darbar, Gurutech Bahadur Nagar, Mumbai, Maharashtra
Source of Support: None, Conflict of Interest: None
The main goal of implant rehabilitation is to achieve osseo-integration. One of the most important features allowing for osseo-integration is primary stability implant. Primary implant stability depends on the quantity and quality of the bone, the fixture design, and the surgical technique used. This article highlights several surgical protocols proposed to enhance the survival of implants in the bone of low density.
Keywords: Low density bone, osseodensification, piezosurgery, primary stability, undersized osteotome
|How to cite this article:|
Dubey AA, Banga PS, Sampat S. Tackling bone density through different osteotomy preparation techniques. Int J Med Oral Res 2021;6:40-2
|How to cite this URL:|
Dubey AA, Banga PS, Sampat S. Tackling bone density through different osteotomy preparation techniques. Int J Med Oral Res [serial online] 2021 [cited 2022 May 20];6:40-2. Available from: http://www.ijmorweb.com/text.asp?2021/6/2/40/326368
| Introduction|| |
Endosteal implants are used in many medical procedures, from dental implants to orthopedic surgery. The main goal of implant rehabilitation is to achieve osseo-integration. One of the most important features allowing for osseo-integration is primary stability (PS) implant.,,
PS can be defined as the mechanical stability between the implant and the bone surrounding the fixture. Primary implant stability depends on the quantity and quality of the bone, the fixture design, and the surgical technique used. Literature suggests that PS is achieved when the micro-motion of the implant has <50–150 μm thresholds before osseo-integration occurs. Mechanical behavior of the bone seems to be a vital factor in the achievement of osseointegration, several classification systems and procedures were suggested for assessing bone quality. The most popular current method of bone quality assessment is that developed by Lekholm and Zarb, who introduced a scale of 1–4, based on both the radiographic assessment, and the sensation of resistance experienced by the surgeon when preparing the implant site. The most common osteotomy surgical technique for implant placement is the bone drilling protocol. However, several protocols were developed to perform implant site preparation without bone drilling, particularly for in poor density bone.
| Bone Classification|| |
An appreciation of bone density and its relation to oral implantology have existed for more than 25 years. Linkow (1970), classified bone density into three categories:
Class I Bone structure: This ideal bone type consists of evenly spaced trabeculae with small cancellated spaces, Class II Bone structure: The bone has slightly larger cancellated spaces with less uniformity of the osseous pattern, Class III Bone structure: Large marrow-filled spaces exist between bone trabeculae.
Lekholm and Zarb (1985) listed four bone qualities found in the anterior regions of the jawbone. Quality 1 was composed of homogeneous compact bone. Quality 2 had a thick layer of compact bone surrounding a core of dense trabecular bone. Quality 3 had a thin layer of cortical bone surrounding dense trabecular bone of favorable strength. Quality 4 had a thin layer of cortical bone surrounding a core of low-density trabecular bone. Irrespective of the different bone qualities, all bones were treated with the same implant design and standard surgical and prosthetic protocol.
| Misch Bone Density Classification (1988)|| |
Dense or porous cortical bone is found on the outer surfaces of the bone and includes the crest of an edentulous ridge. Coarse and fine trabecular bone types are found within the outer shell of cortical bone and occasionally on the crestal surface of an edentulous residual ridge. These four macroscopic structures of the bone may be arranged from the least dense to the most dense; D1 bone is primarily dense cortical bone. D2 bone has dense-to-porous cortical bone on the crest and within the bone, has coarse trabecular bone. D3 bone types have a thinner porous cortical crest and fine trabecular bone in the region next to the implant. D4 bone has almost no crestal cortical bone. A very soft bone, with incomplete mineralization and large intertrabecular spaces, may be addressed as D5 bone. This bone type is most often immature bone in a developing sinus graft.
| Determining Osseous Density with A 2-Mm Twist Drill|| |
This provides information with respect to cortical bone thickness and medullary trabecular bone density. The amount of bone debris found on the twist drill can be interpreted as an indicator of bone quality (e.g. the less debris and a more bloody appearance means softer bone). The four types of mineralized bone have been described by Misch D1 feels like drilling into oak or maple. D2 feels like drilling into pine or spruce. D3 feels like drilling into balsa wood. D4 feels like drilling into Styrofoam. Tactile feedback from the 2-mm twist drill clearly facilitates differentiating between D1 and D4 bone; however, it is difficult to distinguish between the intermediate classes of bone quality (D2 and D3).
| Decisions Based on Bone Density|| |
To reduce the preparation time within the bone to a minimum in D1 bone, the clinician should not apply constant pressure to the drill, but “bone dance” with intermittent pressure for 1 s in the D1 bone and 1–2 s out of the bone while the cooled irrigation is allowed to perfuse the site. In summary, in D1 and D2 bone, a higher speed (1500–2000 rpm) should be used in the preparation of the bone. In poorer quality bone (e.g. D3 and D4), drilling speed is not as crucial; therefore, a lower speed maybe use (~1000 rpm).
| Surgical Modifications to Tackle Poor Bone Density|| |
Several surgical protocols have been proposed to enhance the survival of implants in the bone of low density. Undersized, osteotome, piezosurgery, and osseodensification (OD) drilling were the techniques found in the literature to enhance osseointegration of implants in low-density bone.
| Undersized Implant Site Preparation for Poor Bone Density|| |
The undersized drilling technique that has been introduced to locally optimize the bone density by using a final drill diameter considerably smaller than the implant diameter. This technique has resulted in higher insertion torque values, which are an indicator of improved primary implant stability and may increase the chance of implant success rate 28–30. This technique described previously has been mentioned in the literature under many names, for example, undersized, modified, or adapted drilling technique. The adapted surgical approach by undersizing the implant bed preparation has shown better osseointegration and greater implant stability in animal studies.
| Stepped Osteotomy|| |
Using this method under preparation is performed only in the apical area of the implant site preparation, crestal site is treated with standard approach. A stepped osteotomy provides apical bone contact when indicated for increased PS. In the soft bone, it may be indicated with a stepped osteotomy, i.e. providing apical bone contact when increased PS is desired.
| Osseodensification|| |
OD is a new method of biomechanical bone preparation performed for dental implant placement. The procedure is characterized by low plastic deformation of bone that is created by rolling and sliding contact using a densifying bur that is fluted such that it densifies the bone with minimal heat elevation. OD, a bone nonextraction technique, was developed by Huwais 2013 and done using specially designed burs (Densah™ burs) that help densify bone as they prepare an osteotomy. Standard drills excavate bone during implant osteotomy, while osteotomes tend to induce fractures of the trabeculae that requiring long remodeling time and delayed secondary implant stability. The Densah burs allow for bone preservation and condensation through compaction autografting during osteotomy preparation, thereby increasing the bone density in the peri-implant areas and improving the implant mechanical stability. This facilitates an increased bone plasticity and bone expansion. Huwais demonstrated that OD helped ridge expansion while maintaining alveolar ridge integrity, thereby allowing implant placement in autogenous bone.
| Conclusion|| |
In the presence of poor-bone quality, an undersized protocol is sufficient to improve the PS of the implant; additional decreases do not seem to enhance PS values. OD is a specialized procedure for osteotomy preparation that is inherently bone preserving. Unlike conventional osteotomy, it uses specialized high-speed densifying burs to prepare osteotomy and autograft bone in the phase of plastic deformation. This results in an expanded osteotomy with preserved and dense compacted bone tissue that helps maintain ridge integrity and allows implant placement with superior stability.
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Conflicts of interest
There are no conflicts of interest.
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