There are two basic criteria for patients who desire dental implants. First, the patient must be relatively healthy, with no uncontrolled medical problems, such as uncontrolled diabetes, uncontrolled hypertension or immunosuppressive diseases that hinder the healing process. Second, there must be enough bone to support the dental implant and allow physiologic integration of the implant in the available bone.
Dental implants are simply titanium screws that are threaded into the bone to simulate the root of the tooth. Zirconia implants or a combination of zirconia and titanium are also available today. These are used to attach a single tooth, multiple teeth or the entire dentition or to stabilize an implant retained overdenture.
Pain Management
Most of our patients relate the process of implant placement to be less uncomfortable than a simple extraction. Bone is not innervated per se, but nerves do run through the jaw. An understanding of vital anatomy is critical to the success of our dental implant procedures.
If reflection of the gingiva is made, keeping the incision lines within the attached gingiva minimizes post operative discomfort. Incising into the mucosa results in the release of prostoglandins and increased pain.
Following the procedure, most patients state that if they knew what the surgery was going to be like, they would have done it a long time ago. Of course every circumstance is different, so proper pain management is appropriate. Normally, a dose of 600mg Ibuprofen 3 times a day is adequate to minimize any negative sensations.
Figure 1: Our patient presented with a vertically fractured, non restorable, symptomatic maxillary right central incisor.
Figure 2: Digital periapical radiograph illustrates a root canal treated central incisor.
Figure 3: The CBCT analysis (Vatech Green CT, Vatech America) illustrates the fractured root fragment.
Figures 4 & 5: The non restorable tooth is atraumatically removed using the Golden-Dent Physics forcep.
Figure 6: The attached facial tissue is reflected to expose the facial plate of bone.
Figure 7: A 2.2mm Hahn implant diameter pilot bur makes the initial osteotomy preparation at the proper depth and mesial-distal angulation. The bur engages the palatal aspect of the socket, about 3mm palatal to the facial aspect of the adjacent teeth and approximately 2mm past the apex of the socket.
Figure 8: The osteotomy is widened using the 3.5mm then the 4.3mm diameter tapered bur. These burs are of predetermined length.
Figure 9: A periapical radiograph illustrates the position of the implant. Note that in this immediate placement the implant is positioned about 1mm subcrestal to accommodate for physiologic bone shrinkage.
Figure 10: A cover screw is placed into the implant and the site prepared for grafting of the bone deficiency.
Figures 11, 12 & 13: Allograft material is packed around the implant and around the facial concavity and covered with a passively placed long lasting resorbable collagen membrane. The tissue is closed with suture.
Figure 14: A post operative CBCT is taken illustrating the position of the Hahn implant.
Figure 15: After 4 months of integration, the site is evaluated for final impression. Interdental papilla shape is determined.
Figures 16 and 17: A tissue punch exposes the cover screw and an open tray impression is made using the Miratray technique and medium and heavy body polyvinylsiloxane material.
Figure 18: A taller healing abutment is placed into the implant to prevent the tissue from growing over the site.
Figure 19: The healing abutment is removed showing a healthy tissue cuff.
Figures 20 and 21: A custom Bruxzir abutment is seated. Note the position of the prepared margins, at or just slightly subgingival protecting periodontal health.
Figures 22 and 23: The implant retained crown is cemented providing a functional and esthetic result.
Figure 24: The final periapical radiograph illustrates the plateform switch design of the abutment and proper seating of the crown.
A question that is often asked of the practitioner is, “how long do implants last?” Our modern endosseous dental implants have been successful for over 35 years. The dental implants and overlying prostheses are intended to be permanent, however, many things contribute to their long-term success. These include proper home care, and regular professional maintenance. Engineering is an important part of the success of the dental implant reconstruction. Placing the correct type, size and number of implants for individual situations is important. Cigarette smoking may inhibit proper healing of the soft tissue and integration of the implant in the surrounding bone.
Implant success has increased over the years due to better design of the implant threads providing initial stability during placement, understanding the need to properly support the final prosthesis and the surgical tools used to create the osteotomies.
One factor that affects initial healing around our implants is overheating the bone. It is imperative that proper sharp instruments be used to create the osteotomy site.
Cost Considerations
The cost of implant dentistry has decreased over time. The cost to the dentist has been diminished with more competition in the market place. The investment made in proper and comprehensive implant therapy is an investment to the patient in their overall health and quality of life. Appearance is improved and facial structures are preserved.
There are many factors involved in the cost including the number of implants placed and what type of prosthesis is placed over them. A thorough consultation is required to determine the final cost, but all fees should be presented and accepted prior to any commitment for treatment. Insurance coverage has become more prevalent, up to the limits of the particular policy.
Costs to the dentist should be determined to make the procedure profitable to the practice and also successfully budgeted by the patient and financially affordable. Both material and time must be considered. Fees for the surgical placement and/ or prosthetic fabrication can vary significantly in different areas of the country. Once the general dentist is properly trained in the procedures, factors involved in determining what is charged to the patient include the office overhead, the cost of the implant itself, the prosthetic components including the healing abutment, impression coping, laboratory analogue and final crown.
In the clinical example described here, the hard material cost to the practice is approximately $800-850 which includes the Hahn dental implant, healing abutment, Newport Biologics allograft and resorbable collagen membrane, the impression coping and lab analogue and final Bruxzir zirconia abutment and crown. Operating overhead costs add another $400. These include staffing, impression materials and use of the office space. A total of $1,200 in cost to the dentist for a procedure that has an average national charge of over $4,000 to the patient for the implant/ abutment/crown and graft procedure relates to a very profitable treatment option. The patient too benefits from this high quality, excellent alternative to conventional crown and bridge.
Maintenance and Follow Up
Dental implants do not necessarily require special care for maintenance. However, it is wise for the patient to protect their investment by seeing their dentist and hygienist regularly with proper radiographs periodically made to catch any problems early.
The process of implant surgery and reconstruction takes some time. Although immediate loading of implants is a popular technique, often the dentist may choose to allow the implant to integrate for period of time prior to making the final impressions for the implant retained prosthesis. The amount of time allowed for integration to progress is based on several factors, including the health and healing properties of the patients and the immediate torque achieved upon insertion of the implant.
The literature states that when a minimum of 25Ncm of torque is immediately achieved, a healing abutment can be placed into the implant, thus eliminating the need for uncovering of the implant in the future. There is no need for future anesthesia to the surgical site.
When less than 25Ncm of torque is achieved, it is wise to place a cover screw into the implant and allow the implant to integrate without any intrusion.
If 35Ncm or more of torque is achieved, the implants conceivably could be loaded with some type of transitional appliance.1 It is important for the reader to understand that although initial torque creates initial stability and retention of the implant, over a few short weeks torque will decrease before osteoblasts begin laying down new bone.
Four to six weeks following surgical insertion of the implant into a prepared site, the stability of the implant is reduced. After this time bone formation proceeds and the implant surface is covered with neoformed bone. As more time passes this spongy bone is replaced with compact bone and the implant becomes intergrated.
After 3 to 3.5 months there is minimal morphological and biochemical changes, but the corticalization will proceed up to 12 months after osseointegration.2
Osseointegration is defined and the formation of a direct interface between an implant and the bone, without intervening soft tissue.3 Thus, over time, bone will grow to the surface of the titanium fixture. The implants are thus stabilized initially mechanically through the thread design, but over time are stabilized chemically through direct contact of calcium and titanium atoms.4 Osseointegration occurs by the same process as healing for a fractured bone.5
Bone Loss
Often questions arise on whether bone loss around a dental implant is normal or not. The design of the implant, location of the abutment attachment to the implant relative to the crestal bone, the surface engineering and the hard and soft tissue contours all contribute to the amount of bone remodeling that will occur until the biologic width is formed around the implant and stabilized over time. This biologic width is comprised of supra-alveolar connective tissue and junctional epithelial attachment. There is a vertical and horizontal component of biologic width as it forms and remodels around the implant.
There is a significant difference between the tissue around a natural tooth and that around an implant. Tissue around an implant has more collagen and fewer fibroblasts. The collagen fibers run parallel to the titanium surface without actually attaching to it. Peri-implant mucosa is composed of keratinized oral epithelium, sulcular epithelium and junctional epithelium and underlying connective tissue. The soft tissue interface is made up of epithelium and connective tissue.6 Bone loss may be the result of surgical overheating at the time of osteotomy preparation, periodontal neglect, lack of attached gingiva, as well as diminished healing properties of the patient.
Implants as Treatment Options
Dental implants are excellent treatment options for patients who have endentulous spaces that they want filled, to replace teeth following extraction of those that are non restorable, for patients who want more stability and retention of their conventional removable appliances, and most recently for those patients who simply want fixed dentition and elimination of removable prostheses.
Dental implants are often placed the same day as a surgical extraction. This will depend, however, on the amount of available bone and whether there is any active infection around the existing tooth. When teeth are lost, bone will physiologically shrink in several dimensions. Placing an implant immediately following extraction can minimize bone loss and potentially provide a better esthetic result. The immediate placement of a single dental implant following removal for a fractured and non restorable tooth will be described here.
Benefits of Implants to the Patient
Thus there are many benefits to modern dental implant therapy. These include: increased confidence when smiling, speaking and eating, especially if dentures or partial dentures are replaced or retained with dental implants, elimination of the use of denture adhesives, improved comfort, speech and appearance, preservation of the integrity of facial structures, and adjacent teeth are not prepared for conventional bridges.
Implants can be easier to maintain since they are cleaned like natural teeth. There is often an improved ability to taste food. Our patients look and feel younger, have restored self esteem and an improved quality of life.
CASE STUDY
Our patient is a 58-year-old female with controlled hypertension but no other significant medical finding.
She presented to our practice as a referral from her sister-in-law. Her maxillary right tooth had vertically fractured causing inflammation and discomfort (Figure 1). The periapical radiograph (Figure 2) made, illustrated a root canal treated tooth with the appearance of a radiolucency on the mesial aspect of the root. Along with the clinical evaluation, it was apparent that the root had indeed fractured. CBCT analaysis using the Vatech PaX-i3D Green CT (Vatech America, New Jersey) helped determine the fracture tooth structure, the amount of available bone and prognosis of this tooth (Figure 3).
After discussing possible options, including removal of the non restorable maxillary right central incisor, fabrication of a conventional fixed bridge extending from the non restored right lateral incisor to the maxillary left central incisor, a removable single tooth partial denture or a single implant retained crown, our patient elected for removal of the tooth and placement of a dental implant. Understanding that a dental implant could be placed and used to support a single crown that could be easily maintained with brushing and flossing, and that an additional healthy tooth would not need to be ground down, the patient was ready to proceed.
A decision would need to be made on whether or not an immediate implant could be surgically placed following the atraumatic extraction using the Physics forceps (Figure 4) (Gold-Dent, Detroit, MI). The forcep has two components, the beak which is a shovel shaped edge that engages the palatal surface of the root 1-3mm subgingival, and the bumper which is engaged as high up the vestibule as possible. This serves simply as a fulcrum that allows tension to be placed on the palatal aspect of the root and, over a short minute or two, creates energy and a physiologic release of an enzyme that breaks down the periodontal ligaments. Thus the tooth is elevated up and out of the socket, maintaining the facial plate of bone and any available interseptal bone.
The interseptal bone is what will support the interdental papilla to create the attached gingival triangle between teeth. Without the supporting bone, the interdental papilla will be blunted and the crown will need to be widened to minimize any dark spaces and the gingival height. Figure 1 shows that the conventional crown was already widened and the interdental papilla shortened. Figure 5 shows the atraumatic extraction of the tooth.
An investigation of the available bone is made by making a releasing envelope flap. A horizontal incision is made one tooth over from the edentulous site exposing the facial plate of bone. Note that no vertical incisions are made and access is appropriate.
Keeping the incisions in attached gingiva reduces post operative complications and pain. Making incisions into the mucosal tissue results in physiologic prostaglandin release and post operative discomfort.
Figure 6 illustrates the evaluation of the socket site and health of the surrounding hard tissue. The decision was made to immediately place an implant.
An evaluation of the CBCT indicated a very thin facial plate of bone. Thus the intital osteotomy using the 2.2mm pilot bur (Figure 7) in the Hahn implant surgical kit (Glidewell, Newport Beach, CA) is strategically positioned and angled to engage the palatal aspect of the socket, about 3mm palatal to the facial aspect of the adjacent teeth and at least 2mm beyond the apex of the socket. This helps in achieving initial stability and retention of the implant and will allow room for a custom abutment and implant retained crown to be fabricated and maximize emergence profile and esthetics.
The osteotomy is widened sequentially using a 3.5mm tapered drill to the pre-determined 11.5mm length and then a 4.3mm diameter osteotomy bur (Figure 8). Because the surgical site surrounding bone will remodel as previously discussed, the goal is to place the final implant approximately 1mm into the socket site (Figure 9).
Although 30Ncm of initial torque was achieved, a cover screw is threaded into the Hahn dental implant. Because the extraction socket is shaped like an egg and therefore wider than the implant (Figure 10), the defect was grafted using allograft material from Newport Biologics (Glidewell). The facial defect was also grafted in the attempt to gain some thickness on that surface.
The mineralized cortico-cancellous allograft has sizes of 250-1000 microns (Figure 11). To prevent invagination of epithelium into the socket and protect the graft material, resorbable longlasting collogen membrane (Newport Biologics) is passively placed along the facial contour at least 2mm beyond and defect and onto the palatal aspect (Figure 12). When placed correctly, this membrane will be maintained during the integration phase and will not be avulsed.
Vicryl sutures close the incision (Figure 13). Note that although primary closure was achieved here, it is imperative that there be a band of attached gingiva present around the facial/buccal aspect of any dental implants. This promotes periodontal health and improves the prognosis of any implant. The post operative CBCT (Figure 14) illustrates the positioning of the implant in bone and how the graft material improved facial bone thickness.
Following approximately 4 months of integration, the soft tissue is evaluated (Figure 15). Note here that the interdental papilla is blunted both mesially and distally, as was the case pre-operatively. A band of attached gingiva is present. During the healing period a removable transitionsal “flipper” appliance was used.
A round tissue punch (Salvin Dental, Charlotte, NC) is used to excise the attached gingiva over the cover screw. An open tray impression coping is threaded into the internal design of the Hahn implant (Figure16). A Miratray (Hager Worldwide) was used to make the final impression. This tray is excellent for use in the open tray technique (Figure 17).
Following a conventional impression using medium and heavy body polyvinylsiloxane impression material, a taller 3mm healing abutment is threaded and torqued into the implant (Figure 18). A radiograph is always made with any metal to metal componets to insure a complete and proper seat.
Approximately 3 weeks after the impression, the fabricated custom abutment zirconia abutment and implant retained Bruxzir anterior esthetic crown (Glidewell Lab) is ready to be seated. Figure 19 shows the healthy tissue response following removal of the healing abutment.
Figures 20 and 21 show placement of the custom abutment. Note the margins are at or slightly subgingival. This allows easy cleaning access of any cement used to retain the crown.
The final crown is cemented to place using Improv transitional cement (Salvin Dental). Although the interdental papilla triangles are not ideal and slightly blunted, they are acceptable to the patient (Figures 22 and 23). This final periapical digital radiograph (Figure 24) illustrates a well integrated dental implant with positioning at the available boney crest.
The abutment is designed with the plateform switch design which eliminated the microgap present when abutment and implant are positioned flush. The abutment used is smaller in diameter than the implant plateform. This allows for potentially better bone health and minimizes bone loss around the crestal aspect of the bone-implant interface and can increase soft tissue around the implant plateform, helping in esthetics.7
References:
1. De Oliveira, D, Willya, D. et. al. “Dental Implants with immediate loading using insertion torque of 30Ncm: A Systematic Review. Implant Dentisty,25 (5), Oct. 2016. 675-683.
2. Covani, U.,Cornelini, R. et. al. “Bone Remodeling around implants placedin fresh extraction sockets.” Int. J Periodontics Restorative Dent. Dec: 30 (6), 2010. 601-7
3. Miller, Benjamin F., Deane, Claire B. Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing and Allied Health. Philadelphia: Saunders. (1992)
4. Daview, J. “Understanding peri-implant endosseous healing.” J. Dent. Ed. 67 (8), 2003. 932-949
5. Colnot, C, Romero, DM et al. “Molecular analysis of healing at a bone-implant interface.” J. Dent. Res. 86 (9). 2007. 109-118.
6. Dhir, S., Mahesh, L. et. al. “Peri-Implant and periodontal tissues: A review of differences and similarities.” Compendium. July/Aug 34(7). 2013.
7. Shetty, M, Prasad, K. et. al. “Plateform switching” A new era in implant dentistry.” Int. J or Oral Implantology and Clin Research. May-Aug:1(2). 2010. 61-65
Dr. Timothy Kosinski is an Affiliated Adjunct Clinical Professor at the University of Detroit Mercy School of Dentistry and serves on the editorial review board of Reality, the information source for esthetic dentistry, the Michigan Dental Association Journal, and is the past editor of the Michigan Academy of General Dentistry and currently Associate Editor of the AGD journals. He is a Past-President of the Michigan Academy of General Dentistry. Dr. Kosinski received his DDS from the University of Detroit Mercy Dental School and his Master’s degree in Biochemistry from Wayne State University School of Medicine. He is a Diplomat of the American Board of Oral Implantology/Implant Dentistry, the International Congress of Oral Implantologists and the American Society of Osseointegration. He is a Fellow of the American Academy of Implant Dentistry and received his Mastership in the Academy of General Dentistry. Dr. Kosinski has received many honors including Fellowship in the American and International Colleges of Dentists and the Academy of Dentistry International. He is a member of OKU and the Pierre Fauchard Academy. Dr. Kosinski was the University of Detroit Mercy School of Dentistry Alumni Association’s “Alumnus of the Year,” and in 2009 and 2014 received the Academy of General Dentistry’s “Lifelong Learning and Service Recognition.” Dr. Kosinski has published over 190 articles on the surgical and prosthetic phases of implant dentistry and was a contributor to the textbooks, Principles and Practices of Implant Dentistry, and 2010’s Dental Implantation and Technology. He was featured on Nobelbiocare’s Nobelvision and lectures extensively.
You can reach Dr. Kosinski at: drkosin@aol. com or 248 646-8651. www.smilecreator.net.
