April 1, 2014
by Howard Golan, DDS
Implants have become the treatment of choice to replace missing teeth. It is highly predictable and the refinements of the techniques by surgeons throughout the world have shown minimal morbidity, long-term success and excellent esthetics.
However, implants do have limitations in their attempt to replace lost natural anatomy.
One of the biggest issues with implants is that their diameter, 3-6mm, is often much narrower than the root form they are replacing. This means that when the implant prosthetics emerge from the soft tissue it has to reach a much wider contact point quickly. This can result in the “mushroom” effect, which can create food traps and non-esthetic replacement of the embrasure spaces. Often stock implant parts do not rectify this situation as the emergence profile needed is specific to each tooth/implant situation.
In the anterior, the buccal emergence profile gives the restorative case its esthetics. The clinician overcomes this by under contouring the restorative material so the restoration fits in the arch perimeter. However, this can lead to a “ridge-lap” and thus food trap resulting in patient dissatisfaction and/or peri-implantitis.
In the past, surgeons would sink the implant into the bone to give the clinician “running room” to change the angulation if needed. With tissue level implants however, this running room was eliminated. Today, restorative dentists should be made aware of the width of the implant to be used and then ask the surgeon to provide running room to improve the emergence profiles.
If an implant is too narrow to make the contact point in a natural contour, then a laser could be used to re-contour the tissue collar around the implant to allow a custom abutment or crown to start its expansion to the contact point sub-gingivally. When it emerges from the soft tissue its width is similar to the root form it replaces.
Before we can discuss the treatment phase of this procedure it is important for the reader to understand that lasers are not created equal.
On the market in North America today, lasers cut by two different mechanisms: Heat and Water. Heat lasers such as Diodes and Nd:YAG lasers are effective tissue cutters and provide excellent hemostasis, due to cutting with heat they are relegated to soft tissue cutting. Though reports have been made of using a heat laser around implants, the average clinician needs to be very careful when placing a heat laser around an osseo-integrated implant. Negative thermal effects are unavoidable when using these lasers regardless of gated to continuous wave delivery.
On the other side of the laser spectrum are the Erbium lasers. These lasers absorb highly into water and thus are effective at cutting tissue with minimal negative thermal consequences. The ErCr:YSGG laser (Biolase Technology, Irvine, CA) with a wavelength of 2780nm is highly effective at cutting dental hard tissue as well as soft tissue. When cutting soft tissue, the ErCr:YSGG laser seeks out the water in the soft tissue and ablates it with minimal penetration. Thus, degranulation of an implant can be done without negative effects on the titanium.1
With that in mind, the average clinician can uncover an implant and work around abutments and the implant itself without worry that heat will affect the implant.
Thus, the ErCr:YSGG is ideal for changing the soft tissue around an implant to improve the emergence profile. As a additional benefit, this soft tissue process can be done with the ErCr:YSGG laser often without an injection.
The process begins with assessing the width between the mesial and distal contact points. If the implant width is significantly narrower than the M-D or B-L width then the patient is informed of the need to improve the emergence profile and the cost of doing so. Next, it is determined if there is enough attached tissue around the implant before and after sculpting. If there is not enough attached gingiva then a connective tissue graft or other soft tissue procedure may be needed.
In this example, the width of the implant in the #9(2-1) area is 4.5mm in diameter (Fig. 1). The planned restoration should be 10.3mm in cross section B-L when emerging from the gingiva. Thus, there is a 5+mm discrepancy. Routinely, an impression coping with straight or slightly divergent emergence would be used and the laboratory would fabricate the custom abutment. The custom abutment would have a slight emergence. However even that slight emergence upon delivery would cause significant expansion of the soft tissue. This would cause significant discomfort to the patient and would usually require anesthesia and possible soreness one to four days post-operatively.
In the example case, the implant is uncovered and the soft tissue is contoured to flare the tissue out to create the custom emergence profile. The ErCr:YSGG laser is used to contour the tissue down to the head of the implant. This is done under topical anesthetic (Cetacaine, Cetylite Industries Conshahocken, PA) or no anesthesia at all. Often palatal tissue can be removed with the YSGG laser with no anesthesia since topical anesthetics do not work well on palatal tissue. A temporary abutment is placed to assess what, if any, more contouring is necessary. Note minimal bleeding (Fig. 2).
Once the contouring is complete, a custom impression coping or hi resolution digital scan (Trios, 3Shape, NJ) is used to take the impression. A plastic impression coping can be modified with acrylic or composite to transfer the sub-gingival contour to the laboratory (Fig. 3). Secondly, a temporary abutment contoured the same way or a temporary crown is contoured to match the new emergence profile (Fig. 4).
If this process is done well, there will be no blanching of the tissue upon insertio
n of the custom fabricated abutment (Figs. 5 & 6). No anesthesia is necessary for seating of the abutment.
In conclusion, the narrow and fixed diameters of dental implants can be altered in the soft tissue to improve the emergence profiles around implants. This soft tissue re-contouring is best done with an ErCr:YSGG laser because of its innate ability to contour soft tissue with energized water, thus minimizing the negative heat effects associated with other laser wavelengths. This procedure is easy to do and makes a dramatic improvement in the posterior and anterior implant restorations (Fig. 7).OH
Dr. Howard Golan is a graduate of the University of Michigan School of Dentistry. He completed a general practice residency at North Shore University Hospital on Long Island, NY. After his GPR, Dr. Golan completed a two-year Implant Surgery and Advanced Prosthetic Fellowship at NSUH. He has maintained a busy private practice on Long Island that he shares with his father Dr. Marshall Golan. Dr. Golan implemented lasers into his practice in 2004 and has attained his Mastership certification in the World Clinical Laser Institute. Dr. Golan has been fortunate to be asked to lecture and teach laser-assisted dentistry throughout the United States and Internationally. He is the co-founder of the Center for Laser Education and is a faculty member with the World Clinical Laser Institute teaching Certification Training Courses for that organization.
Dr. Golan has instituted CAD/CAM technology into his practice for 7 years and has lectured on the subject. He is a graduate of the Alleman Center for Biomimetic Dentistry. Dr. Golan has graduated from Concord Law School and has passed the California Bar Examination, obtaining his license to practice law in that state. Dr. Golan’s excels in teaching quick and productive integration of laser-assisted dentistry, minimally invasive concepts and CAD/CAM technology into dental practices. Dr. Golan practices and teaches a Biomimetic philosophy and is passionate about conserving tooth, soft tissue and bone.
1. Miller, Implant Dentistry, Volume 13, 2004