Different Dental Implant Systems
Dental implants have grown in popularity exponentially over the last few years. Despite people having better dental health, losing teeth remains a common problem. With people living longer and expecting to stay active well into their sixties and seventies, being able to confidently smile and eat the foods they enjoy, are expected for long, happy retirements.
Given an aging population, which includes baby boomers, demand for long-term tooth loss solutions is expected to grow. Data from the American Academy of Implant Dentistry indicate 3 million people in the United States currently have dental implants with the figure expected to grow by 500,000 per year. By 2022, the implant market in both Europe and the United States is estimated to be worth more than $4 billion. Increasingly, patients are demanding dental implants in part because of public awareness but also because the procedure has a success rate of 95% making it one of the highest in dentistry.
During this time, technological advancements along with the introduction of new materials and techniques, have increased the reliability and predictability of dental implant treatments. In the next few years, 3D printing and CADCAM technology will transform the market. As such, clinicians today must take several factors into consideration when choosing which implant systems to offer patients and what techniques will be most beneficial to their practices.
Popular Dental Implant Systems Used by Dentists
Available in a variety of sizes and shapes, dental implants have evolved to improve results and adhere to the latest surgical techniques. The leading dental implant manufacturers continue to research how slight changes to the width, shape, length, and surface texture of implants could influence and improve the outcome.
Though more than 100 companies manufacture components for dental implants, only a select group of major companies are well-known and respected. Amongst these companies are:
- Zimmer Biomet
- Nobel BioCare
Why Choose a Popular Implant System?
There are plenty of generic companies that offer less expensive dental implant components but opting to use them can prove to be a poor choice. For starters, patients are increasingly well informed about the various implant technologies and are likely to want their dentist to use devices from a well-known, respected manufacturer. Using implant components with documented evidence of their reliability, can help patients choose their dentist accordingly.
Additionally, any respectable dental laboratory will have familiarity with the top manufacturers and their technicians will have the tools and training necessary to use the components. It is also a great selling point when practices offer implants from one of the leading manufacturers. As the world moves closer to a global economy and people frequently relocate to different countries, knowing their dental components can easily be maintained or replaced wherever they are, provides peace of mind.
Finally, using components from manufacturers with documented track records derived from years of research and development, ensure patients will receive the highest quality and longest lasting treatments. Significant research is performed regarding the surface qualities of dental implants to determine how well they integrate with cells and the biological response promoted. Biomechanical characteristics of dental implants from top manufacturers are clinically researched and the results are available for public review. In contrast, the biomechanical properties of generic implant components are often unknown however closely they replicate a top manufacturer’s implant.
Types of Dental Implants
Once the implant system has been chosen, a decision will be made whether to use screw-retained implants or cement-retained abutments. Choosing between stock vs custom abutments will also be required with custom abutments generally offering better cosmetic results. Titanium implants are preferred by many dentists but zirconia is increasing in popularity. Finally, there are various types of crown that can be used with custom abutments.
Screw-Retained Implants vs Cementable Abutments
Several factors will need to be considered when choosing between screw-retained implant or cement-retained implant crowns including:
- Retrievability: In some cases, it may be necessary to remove an implant crown temporarily. Cements are available on the market designed specifically for implant restorations that claim to make it easier to retrieve the implant crown. Some dentists use temporary cement to affix implant crowns and while this may work, it means the crown has less retention which is not ideal. In contrast, retrieval of screw-retained implant crowns is more predictable especially if a larger number of abutments are necessary.
- Peri-Implant Tissue Maintenance: If cement is used to hold the crown in place, there is a risk that excess cement could extrude into the sulcus. When this occurs, peri-implant tissues can be damaged unless the excess cement is completely removed. The risk of peri-implantitis and peri-implant mucositis are higher when an implant has subgingival cement around it. Despite good techniques existing to remove subgingival cement, the risk remains that cement could be missed. Because cement is not involved, screw-retained crowns avoid this risk and can be removed easily for cleaning and maintenance.
- Ease of Use: Compared to a cement-retained implant crown, it can be more challenging to insert a screw-retained crown especially if fitting multiple restoration units. While a cement-retained restoration with multiple abutments is similar to placing a dental bridge, placing screw-retained restorations require several additional steps to ensure proper fit.
When to Use Custom Abutments
Able to be milled or waxed into the precise shape relative to the tissue crest, custom abutments are suitable for use with either tissue level or bone level implants. Custom abutments can be made of zirconia or titanium or a combination of both. Although typically more expensive than stock abutment, custom abutments offer superior tissue management and esthetics and can be used with both cemented or screw-retained crowns.
When to Use Stock Abutments
Available in standard sizes, stock abutments can be used for tissue level and bone level dental implants. Designed by dental implant manufacturers to be user friendly, stock abutments make taking impressions easier. Typically used with cement-retained restorations, stock abutments are generally less costly than custom abutments but are often reserved for tissue level implants outside the esthetic zone.
One issue stock abutments face is that their standard size means tissue will conform to their shape. Because of this, stock abutments are not optimal to use within the esthetic zone as it will be more difficult to create the ideal emergence profile, provide adequate tissue support, and maximize results.
Why is Titanium Preferred Over Zirconia by Dentists?
Because of its proven track record of biocompatibility with bone, the majority of dental implants are made of titanium. Bone can grow on titanium dental implant surfaces making the implant immovable and the success rate of titanium implants is often 95% or more. Early on, pure titanium was used in dental implants but it was discovered to be too soft so alloys were developed that offer the same biocompatibility with superior strength. In rare cases, patients may have sensitivity or an allergic reaction to the other meals in the alloy.
Because of concerns regarding allergies and sensitivities to titanium alloy, zirconium is being researched and developed to create metal-free implants. Although considered a ceramic, zirconium contains small amounts of two metals, yttrium and hafnium. Extremely strong, zirconia osseointegrates similarly to titanium.
Advantages and Disadvantages of Each Material
After decades of use, titanium dental implants have been shown to function well and remain effective in the long term. While zirconia may prove to be equally effective, its long-term effectiveness is not yet fully understood because of its newness. Because they are available as either one or two-piece systems, titanium implants offer dentists a greater degree of flexibility when planning treatment and placement. Additionally, titanium implants can be used to support overdentures and fixed restorations.
Because they are a single piece, zirconium implants have to be cemented in place. Bone volume is important and with little room for error, care must be taken when placing zirconium implants. Unlike titanium, zirconium will not corrode and is non-conductive thermally. Zirconium’s ceramic color also ensures that the material will not show through the gumline though the possibility of this is rare with titanium implants.
Types of Crowns to Use with Custom Abutments
When custom abutments are placed, crowns including full gold, full-contoured or layered zirconia, e-max, and PFMs can be used. Because temporary cement can hold them, PFMs and full gold crowns offer the most reliable choice and both are good solutions in situations where space is limited. However, esthetics could be a disadvantage of PFMs usage, especially around the gingival margin.
For custom abutments, e-max or lithium disilicate crowns can create successful restorations and using resin cement with them reduces the risk of fracture. One issue with resin cement is that its low viscosity and translucency may make it hard to ensure no sub-gingival cement remains.
Although literature into their long-term effect on tooth enamel and effect on opposing teeth is not available, full contour zirconia crowns have been shown to be successful. For patients concerned with cosmetic appearances, all-ceramic crowns can offer the highest aesthetical results but will rely heavily on the technician’s skills with the materials.