Dental Implant Provisionalization Options

INTRODUCTION
Provisional restorations for dental implant treatment can be challenging and very influential in the desired outcome of the final restoration.¹ There are as many options as there are ideas in today’s practice, and how we choose among them depends upon a host of factors and the science behind them. Considerations for provisional restorations depend upon the health of the implant’s host bone, proper treatment planning, the biomechanics of the situation, soft-tissue concerns, the strength of the materials available, as well as the doctor’s skill set.² Today, the integration of CBCT and CAD/CAM technology has greatly increased our capabilities for creating aesthetic, performance-driven provisional restorations while improving clinical efficiency.³

IMMEDIATE AND DELAYED PROVISIONAL RESTORATIONS
The decision to place a provisional restoration at the time of implant placement depends upon a number of factors; “one treatment fits all” is not an option. Patient selection is critical for adequate primary stability, management of the soft tissue, and patient compliance.⁴ Immediate provisional restorations sometimes are categorized into the following 2 groups: those that are functional and those that are nonfunctional. Some may feel like there is a big difference in these and how they are treated; others contend that single implants act differently than those placed in edentulous arches. Statistically speaking, the failure rates for both are from 0.9% to 1.4%, which falls well within the failure rates for typical 2-stage implants with delayed provisional restorations.⁵ If these are all similar, then why would you delay the restoration at all? It all goes back to using sound implant principles and patient selection. One of the criteria used in evaluation for provisional restorations is the insertion torque value. I have found this number to reside somewhere between 20 and 50 Ncm. We can probably all agree that when this value falls below 20 Ncm, the risk for failure is higher and not ideal. So, what about high torque values, like 50 Ncm and higher? Many clinicians are finding that when implants are placed with high torque values (> 50 Ncm) they show more signs of peri-implant bone loss and subsequent buccal soft-tissue recession.⁶ Soft-tissue management is critical in the decision-making process for provisional restorations and ultimately the long-term success of the final restoration. Papilla maintenance and survival are imperative for implants in the aesthetic zone as well as those in the posterior for emergence profiles and food impaction prevention. The height of the interproximal papilla (Figure 1) around an implant is independent of the proximal bone levels but is directly related to the interproximal bone height (Figure 2) next to the adjacent tooth.⁷ The maintenance of the bony architecture and soft-tissue profile (Figure 3) following the extraction of a tooth or teeth may only be preserved by the placement of an immediate provisional. Most studies show survival rates in excess of 95%; however, we are again back to patient selection and the risk factors associated with these procedures. Thin biotypes, facially positioned implants, and thin/damaged buccal plates are associated with mucosal recession and unfavorable long-term aesthetic results.⁸

Figure 1. Immediate extraction and provisional using the PEEK abutment (BioHorizons).	Figure 2. Placement of a 4.6- x 15-mm Tapered Internal PLUS dental implant (BioHorizons) and the provisional restoration using the PEEK abutment.
Figure 3. Blended composite crown to the PEEK abutment used as the immediate provisional restoration for 4 months following extraction and immediate implant placement.	Figure 4. Hopeless dentition with exostosis and a collapsed bite, this case demonstrates the need for preplanning the bone reduction which was calculated from the treatment planning software.
Figure 5. CBCT preoperative pan (Carestream 8100 [Carestream Dental]).	Figure 6. Volume render (Carestream 8100).

The edentulous arch may have already lost that bony architecture critical for papilla. However, regardless of the final restoration, many of the same risk factors still exist. A thin biotype that is lacking keratinized tissue on an edentulous arch will pose many problems and make treatment planning and case selection all the more important. Efforts to preserve and maintain keratinized tissue in the edentulous arch around implants are of the utmost importance. When the peri-implant keratinized tissue is < 2 mm, the implants are more susceptible to lingual plaque accumulation as well as buccal soft-tissue recession (Figure 4).⁹

CBCT TREATMENT PLANNING
The old carpenters’ saying of “measure twice, cut once” is so relevant in today’s implant dentistry (Fig­ures 5 and 6). CBCT and today’s software give us the ability to view and measure the available bone in all 3 dimensions, identify and isolate anatomical landmarks, as well as overlay the proposed provisional restoration onto the virtual implant positions (Figures 7 and 8). Clinicians and dental laboratory technicians alike are becoming more aware of the benefits of these advanced treatment planning applications. Using known surgical and restorative guidelines to preplan the case is leading to higher success rates and fewer complications (Figure 9).¹⁰ The use of this technology can greatly increase the predictability of our provisional restorations and even the prefabrication of such, prior to the actual surgery. It wasn’t that many years ago that premade clinical provisional crowns and full-arch restorations were a mere Star Trek dream; when, in fact, they are reality, and in some people’s opinion, the standard of care today.

GUIDED SURGERY AND THE PROVISIONAL
Guided implant surgery can be the piece that ties the surgical phase with the restorative phase through the use of a preplanned provisional restoration (Figure 10). When you take into account the bone volume, soft-tissue volume, and the possible virtual restorative outcome, you now have the advantage. Clinical efficiency, predictability, and increased positive patient experience make guided surgery one of the single most important aspects of my practice.

Single-tooth provisionalization options and techniques have been around for a while now. With the success of in-office milling units, some clinicians have the ability to make the provisional chairside after the surgery, while others may have the restoration made along with the surgical guide for an even shorter appointment. None of these techniques are wrong or right; what is important is that the patient is getting the best treatment and the procedure works well in your hands.

Figure 7. Final implant placement and design of the surgical guide based upon the restorative and provisional needs (Implant Concierge).	Figure 8. Edentulous Surgical Guide using fixation pins and the Guided Surgery Kit (BioHorizons); guide made by Implant Concierge.
Figure 9. Initial design of the surgical guide (Implant Concierge).	Figure 10. Upper polymethyl methacrylate (PMMA) provisional restoration for a full-arch case, lab processed.
Figure 11. Converted lower denture used as the provisional restoration following a full-arch case done using the TeethXpress (BioHorizons) protocol.	Figure 12. Upper and lower PMMA provisional restorations following a guided surgery and preplanning of the provisional.

Full-arch immediately loaded restorations can be challenging, to say the least. These restorations take a tremendous amount of presurgical planning, long surgical appointments, and multiple restorative visits. The use of a full-arch mucosa or a bone-borne surgical guide to deliver the dental implants and provisional restoration is, in my opinion, the biggest thing to happen to my practice. The conversion of the prefabricated provisional after implant placement is not only more accurate, but literally saves me and/or my lab technician hours of work (Figure 11). With a 2-year survival rate of nearly 98%, taking into account not only the implant success but also the prosthetic success, it is my experience that this service is highly predictable (Figure 12).¹¹

CLOSING COMMENTS
As Dr. Carl Misch said, “the goal of modern dentistry is to restore the patient to normal contour, function, comfort, aesthetics, speech, and health”; in implant dentistry, this has to involve the use of provisional restorations. Sound surgical and prosthetic techniques along with the use of today’s technology can provide us with exceptional outcomes in an efficient and predictable manner.¹²

Acknowledgment
Laboratory work provided by Nick Herbert of Prosmiles Dental Studio (Rapid City, SD) and surgical guide work provided by Bret Royal of Implant Concierge (San Antonio, Tex).

References

1. Cho SC, Shetty S, Froum S, et al. Fixed and removable provisional options for patients undergoing implant treatment. Compend Contin Educ Dent. 2007;28:604-608.
2. Thor A, Ekstrand K, Baer RA, et al. Three-year follow-up of immediately loaded implants in the edentulous atrophic maxilla: a study in patients with poor bone quantity and quality. Int J Oral Maxillofac Implants. 2014;29:642-649.
3. Guichet D. Digitally enhanced dentistry: the power of digital design. J Calif Dent Assoc. 2015;43:135-141.
4. Yildiz P, Zortuk M, Kiliç E, et al. Clinical outcomes after immediate and late implant loading for a single missing tooth in the anterior maxilla. Implant Dent. 2016 Feb 15. [Epub ahead of print]
5. Degidi M, Piattelli A. Immediate functional and non-functional loading of dental implants: a 2- to 60-month follow-up study of 646 titanium implants. J Periodontol. 2003;74:225-241.
6. Barone A, Alfonsi F, Derchi G, et al. The effect of insertion torque on the clinical outcome of single implants: a randomized clinical trial. Clin Implant Dent Relat Res. 2015 Jun 5. [Epub ahead of print]
7. Kan JY, Rungcharassaeng K, Umezu K, et al. Dimensions of peri-implant mucosa: an evaluation of maxillary anterior single implants in humans. J Periodontol. 2003;74:557-562.
8. Chen ST, Buser D. Clinical and esthetic outcomes of implants placed in postextraction sites. Int J Oral Maxillofac Implants. 2009;24(suppl):186-217.
9. Schrott AR, Jimenez M, Hwang JW, et al. Five-year evaluation of the influence of keratinized mucosa on peri-implant soft-tissue health and stability around implants supporting full-arch mandibular fixed prostheses. Clin Oral Implants Res. 2009;20:1170-1177.
10. Ganz SD. Three-dimensional imaging and guided surgery for dental implants. Dent Clin North Am. 2015;59:265-290.
11. Daas M, Assaf A, Dada K, et al. Computer-guided implant surgery in fresh extraction sockets and immediate loading of a full arch restoration: a 2-year follow-up study of 14 consecutively treated patients. Int J Dent. 2015;2015:824127.
12. Misch CE. Contemporary Implant Dentistry. 3rd ed. St. Louis, MO: Mosby Elsevier; 2008.

Dr. Moody is a 1997 graduate of the University of Oklahoma College of Dentistry. He has been a general dentist for nearly 19 years, and since 2008, he has maintained a practice in Rapid City, SD, limited to implants. He is a Diplomate of the American Board of Oral Implantology/Implant Dentistry and the International Congress of Oral Implantologists, a Fellow and Associate Fellow of the American Academy of Implant Dentistry, an adjunct professor at the University of Nebraska Medical Center, and a mentor at the Kois Center in Seattle. He can be reached at (605) 716-5622 or at justin@justinmoodydds.com.

Disclosure: Dr. Moody is a paid consultant for BioHorizons Implant Systems and Carestream Dental.