New Directions in Dentistry: A Dentistry Today Exclusive Interview with Dr. Gordon Christensen

Dentistry Today


In keeping with the theme of “New Directions” that traditionally has been an area of focus for the February issue of Dentistry Today, we wanted to interview a clinician who has extensive knowledge of all areas of the profession, in order to gain insight into what the future holds for dentistry. As we have done many times in the past, we turned to Dr. Gordon Christensen, who has been a leader in clinical dentistry, research, and education for decades. In this interview Dr. Christensen answers questions that we believe have particular relevance to the dental profession as we begin a new year.

Dentistry Today: You have often noted that general dentists should become more involved in periodontal care. With an increasing body of evidence suggesting that periodontal disease may be linked to various systemic conditions such as cardiovascular disease, do you foresee the general dentist taking a more proactive position in periodontal therapy in the future?

Dr. Christensen: At the moment very few general dentists treat periodontal patients. It is amazing to me that this is the case. I have a workshop each year that brings in one senior dental student from every dental school in the United States, and we observe their level of knowledge and their professional aspirations. We find that they know a lot about periodontics. I convene another group in July called The New Dentist Program, which involves one dentist from every state who has been out of school up to 5 years. I give them a quiz on what they know and what they are doing in their practices. I find that they are doing almost no perio in their practices. My frustration with this is they know a lot, but won’t do it. Even periodontists are becoming less active in treating periodontal disease because they want to do implants.

Dental hygienists and periodontists are the ones treating periodontal disease. I foresee the area of conservative periodontal treatment becoming more active in general dentistry. This increase in activity will probably be on the part of hygienists. I cannot seem to motivate general dentists to want to do perio. I have tried with articles and various personal commitments, yet there seems to be less interest in perio than I would like. I think that if dentists see a so-called profit center in general practice as being a hygiene-based conservative therapy orientation, this may do it.

The potential link between periodontal disease and systemic disease has been of academic interest, and we have all seen articles on this topic in both the professional and lay press, but it has caused almost no activity among general dentists. Some of the procedures I would include as conservative periodontal therapy are well known, and others are not as well known. Patient education is an obvious need. Oral hygiene instruction is necessary, but frankly, it is not too influential among people who have not cleaned their teeth for most of their lives. Tongue cleaning is new to most Americans, although it has been around for a few thousand years. It has been estimated that roughly 50% of people should be cleaning their tongue because of long taste buds and the scum that is left on the tongue, causing bad breath and contributing to generalized periodontal breakdown. Tongue cleaning really needs to be emphasized in conservative perio. Scaling and root planing is well known, but in my opinion, it is often done incorrectly. The dentist, or usually the hygienist, often scales 25 years of calculus off in one visit rather than using more frequent recalls, of perhaps scaling on 2- or 3- month intervals, removing the calculus a little bit at a time. Multiple visits do not hurt the patients, and they are maintained as patients rather than frightening them away. I suggest a revised form of scaling and root planing that is incremental and progresses slowly over several months.

An area that is not as well known, but  which is becoming quite influential in general practice, includes the use of systemic antibiotics. Currently, the main product used is Periostat, which is 20 mg of doxycycline hyclate administered twice a day for up to 9 months. This drug has shown significant positive influence in periodontitis or peri-implantitis patients. I suggest including Periostat in conservative periodontal therapy. There are many rinses on the market now, but the most well known is 0.12% chlorhexidine gluconate. I suggest using this for a couple of months twice a day, and then following it with other agents, such as one of the herbal solutions, the most popular being Tooth and Gum Tonic (Dental Herb Company). Then, follow up with other solutions, such as Listerine, chlorine dioxide, or stannous fluoride rinses. Alternate the solutions every couple of months. Another conservative periodontal therapy is local antibiotics. There are three products that are popular: Atridox from Collagenex, which is doxycycline hyclate; PerioChip from Dexel Pharma, which is chlorhexidine gluconate; and Arestin, which is minocycline hydrochloride. The three of them can be alternated in pockets that are 4 to 5 mm deep. In most states, they can be applied by hygienists.

I have noted that many of the people referred to periodontists are not pleased to undergo surgical therapy, but they are more willing to undergo conservative therapy. Periodontics doesn’t seem to excite general dentists, and this feeling probably will not change. The periodontal need is enormous, but general practice interest is minimal, and even periodontist interest is waning. Dental hygienist treatment potential is high, and conservative therapy is becoming more popular. Since conservative techniques can be delegated to staff persons, it is a source of income as well as a service to patients. Conservative periodontal therapy should grow.

DT: In many clinical situations, implants have become a highly predictable treatment for replacement of missing teeth. However, improvements in endodontics, periodontics, and prosthodontics, including tissue regeneration and bone augmentation, now allow the clinician to save teeth and roots that once were considered hopeless. How do you foresee the role of implants versus tooth/root retention procedures in the future as the treatment of choice in these situations?

Dr. Christensen: I am involved personally with both implant surgery and implant prosthodontics, even though I am a prosthodontist. The advent of implant dentistry is probably the most exciting and significant advancement in the more than 40 years I have been a dentist. However, only a few general dentists involve themselves with implant surgery. Most general dentists will accomplish implant prosthodontics. This concept is contrary to most other developed countries, with the exception of Canada, which is similar to the United States. In Western Europe, South America, and Asia, general dentists do the bulk of implant surgery.

My own belief about tooth retention has really changed since implants have become more widely and successfully used. I am more hesitant to retain teeth that are not sound since I know that implants perform well. I recently made a video on this subject, noting the clinical failures I have encountered by being too heroic in keeping suspect broken-down teeth. I entitled that video, “Dr. Christensen’s Most Frequent Failures and How to Avoid Them.” I have about 60 clinical situations in this video. One of my primary  mistakes has been being too heroic about keeping a broken-down tooth root, including some hemisections. Although I have accomplished many of those, I have had some notable failures. If I encounter teeth that are questionable and I am accomplishing comprehensive dentistry on the patient, I often choose to extract the tooth and place an implant. However, I know that the typical dentist would rather keep the broken-down tooth, or extract it and do conventional dental therapy. There will probably be more retention of teeth due to improvements in endodontics, periodontics, and prosthodontics, but I would really like to see the increased use of implants in those situations where the retention of broken-down teeth is questionable.

DT: Digital technologies are playing an increasing role in dentistry. Has the growth of digital radiography and photography met your expectations? What do you foresee for the future of digital technology in clinical dentistry, particularly in North America?

Dr. Christensen: I am probably a good example of the potential for digital technologies to develop within the profession, since I am a more mature dentist in terms of age and have changed almost totally to digital technology. However, many dentists in my age range and even younger have not done so. Age of dentists is still a determining factor, but it will not be for too much longer. Digital radiography has had slow, although progressive, growth in North America. Reasons for the less-than-expected growth are high cost, difficulty of integrating the concept into the practice, time involvement of incorporating it into the practice, and the cost of converting previous radiographs to digital format. Frustration with the service from some of the digital radiograph companies were very high at first, due to lack of adequate service and lack of support of dentists. More recently, there has been relative satisfaction, particularly among older dentists, with conventional radiography.

Our most recent Clinical Research Associates comparison of digital devices is posted on the CRA website at It allows an actual comparison of the digital devices with conventional radiographs. We used several CRA evaluators in the study and had them observe a comparision between typical conventional radiography and digital radiography. This comparison showed that neither digital nor conventional radiographs are adequate in showing initial dental caries. I was appalled. Some of the digital devices were so bad we couldn’t even detect lesions that were near pulp exposures. Others were as good as, but not better than, D or E speed conventional film. We found that if you are changing to digital, you are doing it for other reasons than better quality radiographs. Either type of image, digital or conventional, showed only about one half of the depth of the actual carious lesions when the teeth were dissected. Their diagnostic ability could not be compared with the radiographs of the 1960s—in the 1960s what you saw on radiographs was what was present on the teeth. Use of a reduced amount of radiation since that time is what has caused the depreciation in radiographic diagnostic ability.

I predict a slow but continued growth of the digital radiography concept because of decreased radiation, immediacy of image observation, storage and retrieval capabilities of the information, and the overall general conversion to digital concepts.

In contrast, digital photography is growing rapidly in the profession. It is very  easy to become proficient with this concept. In many continuing education audiences  I find as many as 60% of dentists use digital photography. It allows excellent patient education opportunities, storage and retrieval of images, immediacy of image viewing, and overall simplicity in producing photographs at a relatively moderate cost. Overall, I predict slow but sure domination of digital integration into all areas of dentistry, but I see the photography leading, with radiography being second showing slow but progressive growth.

DT: Dental materials have certainly evolved quite rapidly in recent years, especially composite resins and ceramics. However, certain clinical problems still exist with these materials. Many people have predicted the demise of conventional materials such as amalgam and metal alloys in favor of “tooth-colored” materials. How do you perceive the relative role of amalgam and metals versus tooth-colored materials in the future, including your forecast for how resins and ceramics will continue to evolve?

Dr. Christensen: This subject continues to be of high interest to dentists and patients. The profession is on the brink of significant improvements in composite resins. Soon we will see lower shrinking resins; we have some with less than 1% shrinkage under evaluation currently. Soon, there will be materials available with more wear resistance than in the past. Polymerization shrinkage and excessive wear have been the two major challenges in resin technology, and improvements in these areas will give justifiably greater emphasis to tooth-colored restorations. These changes will also help polymer crowns achieve acceptance. Some of the polymer crown materials have been disappointing, and only a few have been clinically acceptable. Polymer crowns  need significant improvements, but I don’t think these improvements will be hard to achieve. We have studied five brands of polymer crowns for 4.5 years, and belleGlass and Sculpture Fiberkor have been consistently good products.

I feel that ceramics will continue to dominate the crown market. Lower wear of opposing teeth by ceramic crowns is becoming a reality, but breakage of ceramic materials is still a significant negative factor. At this time, judging from reports from the major laboratories, over 70% of crowns are still PFM; about 92% are tooth colored; and only about 8% are gold alloy.

When considering amalgam versus composite, based on what I see represented by  thousands of dentists in continuing education audiences, resin-based composites are becoming more popular. For small to moderate restorations, the typical American dentist is currently placing composite resin. In the larger restorations or for patients with financial concerns, they are placing amalgam under false pretense, assuming that amalgam is a less expensive restoration. In our evaluations of the economics of amalgam, in most practices amalgam  is a “break even” procedure. Therefore, to say it is less expensive is closing one’s eyes to the facts. It is less expensive because the fee has not been raised to a level where it provides income to a practice. In a public health orientation and where the practitioners are salaried and high overhead is not a problem, amalgam does have a more forgiving nature than composite and it serves well. The difficulty of the composite versus amalgam procedure for experienced dentists is quite equal for the two materials. In terms of the alleged biologic challenges, composite wins.

Taking a look at surveys showing fees for both procedures, the fees charged for both composite and amalgam are too low in relation to many other routine procedures. For example, if we look at a similar time involvement for other procedures, such as single canal endodontic therapy, we find that the latter brings in four or five times the gross income than either amalgam or composite in a similar amount of time. For the future, I have no reservations saying that use of resin-based composites will increase. In crown and bridge, ceramics will reign until resin-based composites  for crowns have made significant improvements.

DT: The controversy about the impact of managed care in dentistry remains at center stage for many dentists. Has managed care negatively affected the practice of dentistry to the degree many once predicted it would? Has there been any positive impact? What is your vision of the future in terms of how dental care is paid for?

Dr. Christensen: Managed care is finding its place in the dental profession. It is not overwhelming the profession as it has in other areas of medicine, but it is definitely a significant portion of dentist income. However, most dentists have found that quality dentistry and economic survival can be found primarily in fee-for- service dentistry. Some young practitioners have suffered financial disasters with dental HMOs. Similarly, the average 20% fee reduction necessary in PPOs has caused even mature practitioners to have severe financial challenges. As an example, assuming a dentist has a 65% overhead, a 20% fee reduction leaves only about 15% before-tax profit. When about 50% overall federal, state, and local taxes are deducted from the 15%, before-tax profit of about 7.5 cents on the dollar of gross income remains for a PPO participant to spend on his or her family. This is pitiful, and it is evident that a dentist cannot participate on a long-term basis in such plans without burning out. I have seen this among many young dentists. They participate in HMOs or PPOs for awhile, thinking that they will obtain adequate income to support their families, but that has not happened in many practices.

Who benefits in DHMO programs? Not dentists, not patients. The HMO companies are the recipients of the financial benefits. Who is gaining in the PPO area? A few patients who would not receive treatment if they were not participating in a PPO. In my opinion, this is the only remotely positive aspect of managed dental care. But are dentists gaining financially? No. Looking at statistics for the year 2000, which is the latest data we have, dental plan enrollment in the United States was as follows: PPOs roughly 40%, indemnity plans roughly 27%, HMOs 19%, and referral plans about 14%. Interestingly and thankfully, dental HMOs dropped 8.3% in enrollment in 2000. However, dental PPOs went up 21%, and dental referral plans, which represent a relatively small part of the market, went up 126%. Dental indemnity, which has been the legitimate portion of managed care for most typical dental practices, sadly went down 18.5% in 2000. According to Harold Childs at the University of Connecticut, “Dental PPOs are now growing at 30% to 40% per year, and will go up to between 60% and 70% of the total.”

Looking at California, which has one of the highest percentages of managed care in the country, at least 65% to 70% of dentists in that state will accept managed care. For California Delta in the year 2000, preferred PPOs grew to 22%; premier indemnity dropped from 66% to 63%; and the Delta Care HMO dropped from 17% to 15%. So, the trend in California is for PPOs to grow and DHMOs to decline. Managed care is somewhat stable in the United States at this time. But as I look at what has happened in dentistry because of DHMOs and PPOs,  I see very little good that has come from either concept, except for a few patients who may be receiving rudimentary care in one of the plans, who would not otherwise receive it. I predict that because of the elective nature of much of dentistry, freedom of choice dentistry will continue to be a significant portion for those dentists who seek it. My advice to dentists is avoid the DHMOs like the worst cancer you can imagine. If you desire to provide quality oral healthcare with freedom of choice for patients, avoid PPOs. Carefully select indemnity plans that are not PPOs in disguise—we are seeing more and more indemnity plans that are dropping a percent or so and thereby becoming PPOs in disguise. Encourage local and national companies to choose direct reimbursement or direct assignment. Thankfully, these concepts are growing, although they are still a small part of payment for dental services. If companies only knew what direct reimbursement would do for their employees, they would go for it.

DT: What is your view of the future of dentistry, including your prediction for the major areas of clinical dentistry in terms of growth?

Dr. Christensen: Overall, the future of dentistry is extremely bright, better than ever in my career. If I were starting out again, I would make the same career decision without a moment’s thought. The overall population ratio is changing to favor dentists. In 1990 there were 59.5 dentists per 100,000 people in the United States, but in 2000 it was 58.4 per 100,000. The publication Managed Dental Care predicts that in 2005 the ratio will drop to 58:100,000; 2010 to 57; 2015 to 55; and by 2020 it will drop to 52 or 53. This ratio is obviously going down, and this means more patients per dentist. One potential negative consequence of this is that there will be fewer dentists to buy practices in the future. For a long time I have encouraged dentists to not depend on the sale of their practices to support their retirement.

Looking at specific areas of dentistry and the trends, the area of diagnostics is increasing in need because of the necessity for diagnostic activity for elective dental procedures. Endodontics has increased significantly, and when endodontics and fixed prosthodontics are combined, they comprise half of the income of general dentists in this country. Aesthetic dentistry is king. Implant dentistry, both prosthodontic and surgical, is stable, but I would certainly like to see an increase in this area by having more general dentists involved. Occlusion is an area waiting to be born—bruxing and clenching affect one third of the international population, and occlusal splints are necessary. Occlusion is an untapped area. Operative dentistry, in spite of predictions it would die, has a higher need because of the aging population. Oral and maxillofacial surgery is up, because the older people get, the more surgical procedures they require. Orthodontics is ready to literally blow up—only 25% of orthodontics is adult currently, and I predict this could go to 40% if adult -oriented procedures are further incorporated into general practice, which is happening now. Pediatric dentistry was supposed to die, but it has turned on again. You just can’t keep kids from eating candy or keep their parents from feeding them various cariogenic foods. Periodontics is not a highly active area.  As I discussed, this area needs rejuvenation. We can’t get general dentists to accomplish periodontics. The treatment need is there, but we need to motivate dentists and patients into conservative periodontal therapy. In the area of preventive dentistry, about 10% of the typical general dentist’s patient population needs heavy preventive therapy, ie, chemotherapy and radiation therapy patients, bulemics, senile individuals with caries, juveniles with caries, and tobacco chewers. Many of them need heavy fluoride, which is a win-win situation in terms of economics for the dentist and hygienist, and it is certainly a service to the patient. Prosthodontics—fixed, implant, maxillofacial, and removable—were predicted to die. When I helped start a dental school 30 years ago, I was told not to start a prosthodontics department because there would not be any prosthodontics by the year 2000. Now the combined area of prosthodontics is probably providing upwards of 50% of the general dentist’s income. This area will continue to grow.

Except for my concerns about managed care, I don’t have a negative thing to say about dentistry. The future of the profession is very bright.

Dr. Christensen is cofounder and senior consultant of Clinical Research Associates and director of Practical Clinical Courses. He has lectured throughout the world and presented over 40,000 hours of dental continuing education courses. He has published hundreds of articles and books and developed several hundred videos and DVDs. He maintains a practice in Provo, Utah. He can be reached at (801) 266-6569, info@pccdental, or