The Future: Materials, Challenges in Dentistry, and Education



Gordon Christensen, DDS, MSD, PhD

In an interview conducted by Dr. Damon Adams, Dentistry Today’s editor-in-chief, Gordon Christensen, DDS, MSD, PhD, candidly expresses his thoughts on current topics affecting the profession. Dr. Christensen is founder and director of Practical Clinical Courses and CEO of CLINICIANS REPORT, Provo, Utah.

What category of dental products needs the most improvement today?
Dr. Christensen: Resin-based composites comprise two thirds of the posterior direct restorations placed in the United States during 2010, with amalgam being the other one third. The longevity of Class II composites, according to meta-analyses, is only 6 years. Since composite is such a commonly used material, it needs improvement in ease of use, more adequate conversion and polymerization, less wear in service, and certainly improvements in the techniques that dentists use to place the material.

Should dentists abolish the use of amalgam and place only resin-based composite for direct posterior restorations?
Dr. Christensen: This is one of the most controversial questions in dentistry and has been so for more than 150 years. Amalgam continues to be used at least “some of the time” by the majority of dentists in the United States. In discussions with Tom Limoli, of Limoli and Associates, I have been told that during 2010, two thirds of the direct posterior restorations in the United States were composite, and that one third was amalgam. In surveys in our own group, CLINICIANS REPORT, we have found that the majority of dentists still occasionally use amalgam. There is no question that on the average, as observed in meta-analyses on this topic, amalgam serves almost twice as long as composite in Class II situations. The age-old argument over the alleged “toxicity” of amalgam still rages. Amalgam use is still sanctioned by the ADA and the WHO. Some dentists are vehemently opposed to amalgam, and others consider the toxicity subject to be foolish. At this time, the question is unanswerable.

Should zirconia-based and/or full-zirconia crowns replace PFM crowns?
Dr. Christensen: There is no question that PFM restorations are serving the profession well and that they have an impressive longevity potential. There is also no question that the use of PFM restorations has gone down significantly in the past 3 years. The cost of metal is now so high that dentists are looking for lower cost alternatives for indirect restorations. Zirconia-based restorations have now matured during the 10 years they have been in use, and they are starting to prove themselves as viable restorations. Full-zirconia restorations have been used only about 2 years, and they too are starting to prove themselves. However, as with any new concept, time will be required for full acceptance of these restorations. I feel that that they and other all-ceramic options, such as IPS e.max (Ivoclar Vivadent), will gradually replace PFM.

Manufacturers often feel compelled to introduce new products, sometimes before they are ready for clinical use, or sometimes to have a similar product to another company that may be currently selling well. What are your thoughts regarding this practice, and what categories of current technology or products may fall into this situation?
Dr. Christensen: Products have to be introduced as soon as a company feels relatively confident that they are working. If they are not introduced, the resources that went into research and development would soon disallow any profit for the company. Almost all new products could use more scientific research and more clinical observation before they are introduced. I see no way to overcome this challenge.

Are implant abutments best made from metal or zirconia?
Dr. Christensen: Zirconia implant abutments serve several purposes very well when implants are deeply below the gingival tissues. They eliminate the gray soft-tissue color potential caused by metal abutments, and placing the margin of the restoration just apical to the gingiva allows easy cement removal. In typical cases where implants do not have significant soft-tissue challenges, metal abutments are well-proven to be strong and easily used. Both types have their advantages and disadvantages, but the metal abutments are the choice of many dentists when their use is appropriate.

Are small-diameter implants (< 3 mm in diameter) as predictable as conventional diameter implants (3 mm or larger in diameter)?
Dr. Christensen: When small-diameter implants are placed correctly, they are serving well. It is the policy of most experienced small-diameter implant users to place 2 small-diameter implants to equal the surface area of one conventional diameter implant. Where 2 conventional implants may be desirable and acceptable for support and retention of a mandibular complete denture, 4 small-diameter implants have been proven to be adequate. In my opinion, these small-diameter implants have been unjustifiably maligned by some dentists who have not even used them. They have enormous potential for those patients who cannot afford, are too debilitated for, or who do not desire conventional-diameter implants.

Practical Clinical Courses hands-on course participants. Reception area for CLINICIANS REPORT (CR) Oral Health Center.
Operatories for CR Oral Health Center.

What can be done to reduce the reported 20% failure rate in American general dentist endodontic procedures as stated in recent surveys?
Dr. Christensen: Endodontists report success in the high 95% level, while reports state only 80% success for the profession at large. New, more effective methods for root canal debridement are needed immediately. Better disinfection materials are needed. Endodontic cements that do not leak are needed immediately. In other words, as I look at the endodontic therapy done by the profession in the United States at large, we need a major jump forward. Innovative, creative thinking and planning are needed to overcome the obvious failure rate of current endodontic therapy as accomplished in typical general practices. It appears that merely educating dentists to use the current available techniques known well to endodontists is not enough.

Where do nonconventional, so-called “plastic orthodontic” techniques fit into overall orthodontic therapy methods?
Dr. Christensen: Nonconventional orthodontic procedures have had great acceptance by patients, especially adult patients. There have been many dentists who have learned about how to use the conservative techniques, and some have adapted their practices to use them routinely. These conservative, nonconventional orthodontic procedures are particularly well suited for minimal to moderate orthodontic needs where there is not a need for major orthodontic movement.

What are the main challenges facing our profession today?
Dr. Christensen: I have polled the profession to determine the main challenges facing the dental profession at this time and reported 20 of them to the ADA Board of Trustees in August of 2011. Twenty high concerns were identified. The top 9 reported to me electronically as the highest priority by thousands of US dentists were:

  • Third-party involvement in setting fees and dictating treatment
  • The increasing numbers of new dental schools starting all across the United States, most not in conventional universities and without the usual presence of research and public service. Some starting in states already overpopulated with dentists
  • High dental school tuition
  • The obvious current overproduction of dentists and dental hygienists
  • The increasing proliferation of “corporate dentistry” across the country
  • The threat of midlevel practitioners
  • Increasing influence of off-shore dental laboratory products
  • Lack of ADA accredited dental laboratory technology schools
  • Need for more practice-related research versus the fringe subjects seen in many dental journals currently.
Technologies in Restorative And Caries Research, CR’s in-depth research division, is directed by Dr. Rella Christensen.

What are your thoughts regarding the observed level of clinical experience and knowledge of new dental graduates?
Dr. Christensen: New graduates have far more to learn than previous generations of dentists. As a result, they have more superficial knowledge and experience in the basics when they graduate than previous generations. Many dentists selecting associates have voiced to me the relative lack of clinical experience and knowledge in the new graduates they select as potential practice partners.

Do you see or observe any generational differences between new dentists compared to more experienced dentists in terms of ethics or quality of care provided to patients?
Dr. Christensen: Many mature dentists have expressed concern to me that new graduates as a whole are not as concerned with ethics as in the past. Government mandates that advertising is acceptable, large student debts on graduation, and a general feeling of financial entitlement, are among the reasons for the change in ethical concern and practice.

Continuing education (CE) seems to be experiencing a major shift in how it is delivered and who is attending. Is this a good change, and what are your thoughts on this change?
Dr. Christensen: CE is in a major state of flux. As one who has presented thousands of courses during the past several decades, I can see enormous changes. Young dentists are not attending courses as they did in the past. They are more interested in observing CE on the Internet. This mode of CE precludes their interaction with peers, disallows of discussion with manufacturers and distributors, allows use of information that may or may not be reliable from sources that are often unknown, eliminates hands-on learning, eliminates study clubs with their proven advantages, and numerous more negative factors. It is my strong opinion that mature practitioners who know the value of conventional integrative CE should encourage young practitioners to attend CE and to participate with their peers and with the manufacturers and distributors of products. In other words, I feel strongly that we are going in the wrong direction with CE. The Internet is good for some education, but it lacks many of the requirements for adequate learning.

What makes CR different from all the other dental product evaluation organizations?
Dr. Christensen: Clinical Research Associates, now called CLINICANS REPORT, has now been in existence for 35 years. It was started on the premise that new products should be evaluated rapidly, preferably before market introduction, by nonbiased researchers not receiving money from manufacturers to accomplish the research. It has always had both strong basic science components and clinical practicing dentist evaluators. It is a nonprofit organization. Both of the cofounders, Drs. Gordon and Rella Christensen, have never had any personal income from the organization. None of the evaluators receive any financial income. The dentists involved are from all areas of the world, representing all aspects of the profession. We are told that the honesty of CR is a respected aspect of the organization. All a company has to do to be recognized by CR is to produce a product that is faster, easier, better, and/or less expensive than others and CR will research the product thoroughly and report on it. There are no financial motives in CR. Funding comes from the profession through subscriptions, speaking by staff, and donations.

A small group of dentists that educate other dentists are now called by some, “key opinion leaders.” Often, they are somewhat influential on the direction of dental products and devices. What are your thoughts regarding this group?
Dr. Christensen: This question is a well-known one among practitioners. The group is self-limiting, because recognition of who is honest, reliable, predictable, and not self-serving requires only a short time to be acknowledged. I have seen virtually hundreds of “opinion leaders” come on strongly, only to die down within about 3 years. They do not have the characteristics defined above. Practitioners soon recognize the speakers’ motives. Perhaps they are biased toward a specific company. Perhaps they are salaried by a specific company, Perhaps they do not have access to any research on the topics on which they are speaking. Their motive may be money, recognition, and ego enhancement, which soon become evident to the profession. The “wheat” soon separates from the “chaff”; they die down on the lecture circuit and disappear. The small group of trusted speakers (key opinion leaders) is well known to practitioners and to manufacturers and retailers. They are in high demand, enjoy their work, stay in demand for decades, and are a valued service to the profession and the patients we serve.

Dentistry is often viewed very differently and appears divided based upon those clinicians’ primary roles; for example, those in education at dental schools, dentists working for manufacturers, corporate dentistry, specialists, dentists in the “trenches,” lecturers on the “circuit,” etc. Having been involved in many of the above example groups, what are your thoughts regarding the divisions and directions of dentistry as viewed by these groups?
Dr. Christensen: I have long encouraged vocally and in publications the integration of the aforementioned groups. We should be a team: educators, practitioners, researchers, public health leaders, politicians, manufacturers, distributors, staff members, technicians, and others, and just as a football team has specific players doing specific tasks, such should be our profession. The lack of respect of those persons within some the categories of dentists for other categories is appalling to me. There are many things I can do well, and there are myriad others for which I desperately need help from other members of the team. The long present “town/gown” split is still highly evident in the profession. I will candidly admit some persons have inadvertently put up walls between their group and the others, while others purposely express their superiority over other groups. In my opinion, this unfortunate situation will always exist, but it is also unjustifiable. We are a team, and in some situations, we actually work that way. I am optimistic to see some mild progress toward integration.

On behalf of all of us at Dentistry Today, we want to take this opportunity to sincerely thank you, Gordon, for providing timely and valuable information to share with our many readers. You have been an inspiration to so many in the profession, and your lifetime of hard work and obvious dedication are truly appreciated by everyone you have touched. Wishing you all the best for many more years of continued success!

Dr. Christensen is founder and director of Practical Clinical Courses (PCC) and CEO of CLINICIANS REPORT (CR) in Provo, Utah. Dr. Christensen has presented more than 45,000 hours of continuing education throughout the world and has published many articles and books. Dr. Gordon Christensen and Dr. Rella Christensen are cofounders of the nonprofit CR (previously CRA), which she has directed for many years. Since 1976, they have conducted research in all areas of dentistry and published the findings to the profession in the well-known CRA Newsletter now called CLINICIANS REPORT. His degrees include: DDS, University of Southern California; MSD, University of Washington; PhD, University of Denver; and 2 honorary doctorates. Early in his career, he helped initiate the University of Kentucky and University of Colorado dental schools and taught at the University of Washington. Dr. Christensen is a practicing prosthodontist in Provo, Utah. He can be reached at (801) 226-6569 or via e-mail at


Disclosure: Dr. Christensen reports no disclosures.