Harold C. Slavkin: A Transformative Leader of Our Times

Harold (Hal) C. Slavkin, DDS, the 22nd president of the American Association for Dental, Oral, and Craniofacial Research (1993 to 1994), died on December 22, 2023. During a career that spanned almost 6 decades, Hal distinguished himself as an international authority on craniofacial biology and an advocate for oral health equity. He served as dean of the University of Southern California's dental school, founded the school's Center for Craniofacial Molecular Biology, created the nation's first PhD program in craniofacial biology, and served as the sixth director of the National Institute of Dental and Craniofacial Research. Hal's studies of the molecular and cellular underpinnings of craniofacial malformations prepared him to champion translational research later in his career, when his work with patient advocates revealed the importance of applying new discoveries to clinical practice. A visionary thinker, skilled administrator, progressive educator, compelling communicator, researcher, scholar, and mentor, Hal was known as a Renaissance leader. He rejoiced in fostering collaborative synergies among people and organizations. Throughout his life, family was his central grounding force. He and his wife, Lois, advanced a wide range of social and community initiatives and took great pride in their children, grandchildren, and great-grandchildren. We remember Hal for his indelible spirit, unflappable enthusiasm for science, fierce advocacy for social justice, and infectious zest for life. Here, we outline his multidimensional accomplishments through the lenses of academia, government, and nonprofit organizations. Although it is with heavy hearts that we bid goodbye to this remarkable man, our spirits are lightened by the many gifts he left behind.

Preventive dental care is associated with improved health care outcomes and reduced costs for Medicaid members with diabetes

Introduction

Preventive dental services have been associated with improved health outcomes. This study expands on previous observations by examining the relationship between oral health care and health care outcomes and costs in a publicly insured population with diabetes.

Methods

Utilization of dental services, health care outcomes and costs were evaluated for New York State Medicaid members with a diagnosis of diabetes mellitus (DM), ages 42 to 64, who were continuously enrolled between July 1, 2012 and June 30, 2015. Utilization of dental services focused on preventive dental care (PDC), and extractions and endodontic treatment (both indicative of advanced dental infection). Data were analyzed using regression models with propensity score weighting to control for potential confounding.

Results

Receipt of PDC was associated with lower utilization rates and costs compared to members who did not access dental services. The most pronounced average cost difference was observed for inpatient admissions at $823 per year for members who had at least one PDC without extraction or endodontic treatment. Each additional PDC visit received was associated with an 11% lower rate of inpatient admissions and lower average inpatient costs by $407 per member. The need for a dental extraction or endodontic therapy was associated with relatively higher rates and costs.

Conclusions

These findings demonstrate an association between PDC and improved health care outcome rates and lower average costs among members with DM and suggest a general health benefit associated with provision of preventive dental care for persons with DM.

Securing Public Trust: Dentistry, SARS-CoV-2, and "Testing for Tomorrow"

The SARS-CoV-2 pandemic created societal upheaval well beyond what anyone, but the oldest of Americans, has seen in their lifetime. As the pandemic begins to subside, it is leaving behind a legacy of permanently changed practices, including enhanced environmental controls in clinical settings, reconsideration of modes of personal protective equipment outsourcing, changes and/or reinterpretation of dental practice acts, and entirely new approaches to testing and vaccine design, among many others. This article focuses on one change that the authors hope will prevail: greater trust in the dental profession as a valuable public resource during healthcare crises. The article cites the initial low perception of dentistry as an important component of a health surge response by public health authorities, then describes how a group of eight institutions came together to form the "Testing for Tomorrow Collaborative" to help each other and the dental profession identify modes of testing and practice conduct that make dentistry safer to practice. The importance of the public's trust in the profession is underscored, and pathways to improving that trust are proffered.

Dental Services and Health Outcomes in the New York State Medicaid Program

Previous reports suggest that periodontal treatment is associated with improved health care outcomes and reduced costs. Using data from the New York State Medicaid program, rates of emergency department (ED) use and inpatient admissions (IPs), as well as costs for ED, IPs, pharmacy, and total health care, were studied to determine the association of preventive dental care to health care outcomes. Utilization of dental services in the first 2 y (July 2012-June 2014) was compared to health care outcomes in the final year (July 2014-June 2015). Costs and utilization for members who did not receive dental services (No Dental) were compared to those who received any dental care (Any Dental), any preventive dental care (PDC), PDC without an extraction and/or endodontic treatment (PDC without Ext/Endo), PDC with an Ext/Endo (PDC with Ext/Endo), or Ext/Endo without PDC (Ext/Endo without PDC). Propensity scores were used to adjust for potential confounders. After adjustment, ED rate ratios were significantly lower for PDC and PDC without Ext/Endo but higher for the Any Dental and Ext/Endo without PDC. IP ratios were lower for all treatment groups except Ext/Endo without PDC. ED costs differed little compared to the No Dental group except for Ext/Endo without PDC. For IPs, costs per member were significantly lower for all groups (-$262.91 [95% confidence interval (CI), -325.40 to -200.42] to -$379.82 [95% CI, -451.27 to -308.37]) except for Ext/Endo without PDC. For total health care costs, Ext/Endo without PDC had a significantly greater total health care cost ($530.50 [95% CI, 156.99-904.01]). Each additional PDC visit was associated with a 3% reduction in the relative risk for ED and 9% reduction for IPs. Costs also decreased for total health care (-$235.64 [95% CI, -299.95 to -171.33]) and IP (-$181.39 [95% CI, -208.73 to -154.05]). In conclusion, an association between PDC and improved health care outcomes was observed, with the opposite association for Ext/Endo without PDC.

Connecting dental education to other health professions

The health care delivery system is poised for substantial change in the coming years. The foremost vector driving this change is economics. However, use of evidence-based principles of practice and a high desire, if not a national mandate, for increased quality in health care delivery are also very important factors. Nestled within this large national health care debate are a set of issues that directly impact dental education and practice. Among them is the potential impact of expanded intraprofessional and interprofessional collaborations among dentists, dental therapists, dental hygienists, and nurse practitioners, among others, in search of better oral and general health care for all Americans. This article explores many of the issues involved in this possible transition with special reference to the impact of the changes on dental education.

Identifying unaddressed systemic health conditions at dental visits: patients who visited dental practices but not general health care providers in 2008

We assessed the proportion and characteristics of patients who do not regularly visit general health care providers but do visit dentists and whose unaddressed systemic health conditions could therefore be identified by their dentist. Of the 26.0% of children and 24.1% of adults that did not access general outpatient health care in 2008, 34.7% and 23.1%, respectively, visited a dentist. They varied by census region, family income, and sociodemographics. Dental practices can serve as alternate sites of opportunity to identify health concerns among diverse groups of US patients.

Teaching implant dentistry in the predoctoral curriculum: a report from the ADEA Implant Workshop's survey of deans

In 2004, a survey of the deans of U.S. and Canadian dental schools was conducted to determine the implant dentistry curriculum structure and the extent of incorporating implant dentistry clinical treatment into predoctoral programs. The questionnaire was mailed to the deans of the fifty-six dental schools in advance of the ADEA Implant Workshop conference held in Arizona in November 2004. Out of the fifty-six, thirty-nine responded, yielding a response rate of 70 percent. Thirty-eight schools (97 percent) reported that their students received didactic instruction in dental implants, while one school (3 percent) said that its students did not. Thirty schools (86 percent) reported that their students received clinical experience, while five schools (14 percent) reported that theirs did not. Four schools (10 percent) did not respond to this question. Fifty-one percent of the students actually receive the clinical experience in restoring implants, with the range of 5-100 percent. Of those schools that provide clinical experience in restoring implants, four schools (13 percent) reported that it is a requirement for them, while twenty-eight schools (88 percent) reported that it is not a requirement for them. Three schools (9 percent) did not respond. The fee for implants is 45 percent higher than a crown or a denture, with a range of 0-100 percent. Twenty-nine schools (85 percent) indicated that they did receive free components from implant companies, while five schools (15 percent) did not. The conclusions of this report are as follows: 1) most schools have advanced dental education programs; 2) single-tooth implant restorations are performed at the predoctoral level in most schools; 3) implant-retained overdenture prostheses are performed at the predoctoral level in most schools; 4) there is no predoctoral clinical competency requirement for surgical implant placement in all schools that responded to the survey; 5) there is no predoctoral clinical competency requirement for implant prosthodontics in most schools that responded to the survey; 6) prosthodontic specialty faculty are often responsible for teaching implant prosthodontics at the predoctoral level; 7) periodontics and oral and maxillofacial faculty are commonly responsible for teaching implant surgery at the predoctoral level; 8) support from implant companies is common for dental schools, with most providing for implant components at discounted costs; and 9) there is a lack of adequately trained faculty in implant dentistry, which is a significant challenge in providing predoctoral students with clinical experience with dental implants.

Introducing a senior course on catastrophe preparedness into the dental school curriculum

This article describes an integrated fourth‐year course in catastrophe preparedness for students at the New York University College of Dentistry (NYUCD). The curriculum is built around the competencies proposed in “Predoctoral Dental School Curriculum for Catastrophe Preparedness,” published in the August 2004 Journal of Dental Education. We highlight our experience developing the program and offer suggestions to other dental schools considering adding bioterrorism studies to their curriculum.

Introducing a senior course on catastrophe preparedness into the dental school curriculum

This article describes an integrated fourth-year course in catastrophe preparedness for students at the New York University College of Dentistry (NYUCD). The curriculum is built around the competencies proposed in "Predoctoral Dental School Curriculum for Catastrophe Preparedness," published in the August 2004 Journal of Dental Education. We highlight our experience developing the program and offer suggestions to other dental schools considering adding bioterrorism studies to their curriculum.

Dentistry, nursing, and medicine: a comparison of core competencies

Health care, including oral health care and oral health education, is under great stress in the United States. The cost of and access to care, the cost of dental education, and a shortage of educators have led leaders in dental education, organized dentistry, and the public sector to underscore the problem. One of the proposed solutions is to find synergies and new health care and education models by building bridges among the health professions. One potential solution is being implemented at the NYU College of Dentistry (NYUCD). Dentistry and nursing are seemingly unrelated professions, and they are rarely if ever modeled together. That is about to change with the joining together of NYUCD and the Division of Nursing of the NYU Steinhardt School of Education in creating a College of Nursing within the College of Dentistry. This process has not been without controversy. Following the Division of Nursing's request to join NYUCD, and the subsequent announcement of the proposed combination by NYU in December 2004, some members of the dental profession responded by questioning the appropriateness of the merger and the similarity of the two programs. Nevertheless, substantial parallels exist in the education and practice of dentists and nurse practitioners (NP) including basic, social, and some clinical science education, practice models, research synergies, and community service. However, similarities in the core competencies of these professions have not been analyzed formally and in detail. Accordingly, the purpose of this study was to compare the core competencies of nurse practitioner and dental education programs. The results show a surprising overlap of the core competencies of the dental and nursing professions (38 percent partial or total overlap). A similar overlap with medicine also exists, albeit lower (25.4 percent). These results are notable because they demonstrate that the three health professions, independently of one another, developed very similar basic competencies and learning objectives. These data should encourage other health professions programs to seek new collaborative models for education, beyond the current silos of training, and new health care delivery systems as has been strongly recommended by the Institute of Medicine. Such collaborative education redirects health care toward providing truly interdisciplinary comprehensive primary care for patients.

Predoctoral dental school curriculum for catastrophe preparedness

Preparing for catastrophic events, both human-made and natural, is in the national interest and has become a priority since catastrophic events in Oklahoma City, Washington, DC, and New York City. Dentists are a large source of non-physician health manpower that could contribute to the public welfare during catastrophic events that require additional public health human resources. Dentists, by virtue of their education, understand biomedical concepts and have patient care skills that can be directly applied during a catastrophic event. Dentists also can provide training for other types of health care workers and can supervise these individuals. In this article, we propose that dentistry can make a significant contribution as part of a national response before, during, and after a catastrophic event or at the time of a public health emergency. We describe the potential collaboration among a dental school, city and state health departments, law enforcement, the military, and others to develop a curriculum in catastrophe preparedness. Then we describe one dental school's effort to build a catastrophe preparedness curriculum for our students. The competencies, goals and objectives, and sources of content for this catastrophe preparedness curriculum are described as well as suggestions for sequencing instruction.

Meeting a disaster's medical surge demand: can dentists help?

No one can deny that these are extraordinary times in world affairs. This is true not because there is turmoil in the world, which tends to be the norm, but because the problems in the world are dominated not by countries or religions, but by individuals and radical sects for whom life seems far too expendable. It is a time for each of us to determine how to respond to help protect our families. It is also a time for dentists to assess how they should respond to meet the additional demands placed upon them by way of their professional licenses and underlying responsibility to society. This article frames a set of commitments that the profession should consider assuming. It is related from the perspective of an institution that has taken an active role in societal protection from before Sept. 11, 2001, to the present. The discussion includes a description of the nature of medical surge demand and why the dental profession is uniquely positioned to assist in meeting this demand. The skill set of the dentist is highlighted in terms of triage ability, a role in bio-surveillance, the capacity to calm the "worried well," and community responsiveness. In addition, concepts like shelter in place and the Medical Reserve Corps are explained, and valuable reference sources and websites are provided.

Bioterrorism and catastrophe response: a quick-reference guide to resources

BACKGROUND

Dentists' responses to catastrophe have been redefined by bioterrorism. Informed response requires accurate information about agents and diseases that have the potential to be used as weapons.

METHODS

The authors reviewed information about the most probable bioterrorist weapons (those from the Center for Disease Control and Prevention's Category A) from the World Wide Web and print journals and distilled it into a resource list that is current, relevant to dentistry and noncommercial. The Web sites cited include those sponsored by federal agencies, academic institutions and professional organizations. The articles cited include those published in English within the last six years in refereed journals that are available in most higher education institutions.

RESULTS

The authors present the information in a table that provides a quick-reference guide to resources describing agents and diseases with the greatest potential for use as weapons: anthrax, botulism, plague, smallpox, tularemia and viral hemorrhagic fevers. This article presents Web site and journal citations for background and patient-oriented information (fact sheets), signs and symptoms, and prophylactic measures and treatment for each of the agents and diseases. The table facilitates quick access to this information, especially in an emergency. This article also points out guidelines for response should a suspected attack occur.

CONCLUSIONS

Armed with information about biological weapons, dentists can provide faster diagnosis, inform their patients about risks, prophylaxis or treatment and rethink their own role in terrorism response.

CLINICAL IMPLICATIONS

Fast, accurate diagnosis limits the spread of exceptionally contagious diseases. Providing accurate information to patients minimizes misinformation and the associated public fear and panic that, unchecked, could overwhelm health care systems.

Capacity for training in clinical research: status and opportunities

The ability to base patient care on scientific evidence depends in part on the results of translational and applied research. The shortage of trained clinical researchers identified by several sources limits the availability of clinical research studies upon which to base evidence-based therapeutics. This premise suggests that the dental profession needs to train more clinical researchers and faculty to conduct clinical research and to teach its applications to practice. Increasing opportunities for clinical research training in a variety of settings should eventually increase the numbers of clinical researchers, raise faculty involvement in clinical research, and promote science transfer. This paper reports on the current status of clinical research in dental schools, specifies the diverse groups involved in the clinical research enterprise, and identifies underutilized opportunities and partnerships for clinical research training. Data on federal and nonfederal funding of clinical research and training programs are presented. Existing and novel mechanisms for expanding clinical research training throughout and across traditional as well as unconventional environments are explored.

Dental education: one dean's perspective

A dean looks at dental education and the practicing profession from the perspective of three years in dental school administration and sixteen in industry. A significant challenge is to balance costs and standards in the face of well-meaning calls for benefits from those who are not charged with meeting costs. One issue of central importance for education is keeping the curriculum properly positioned in a dynamically evolving profession. The knowledge and skills needed to manage the practice pharmacopeia are used as an example of this problem. It is proposed that schools adopt a future orientation. Dental education must be valued within the higher educational community just as dentistry is valued for its contributions to society at large. Any drift toward proprietary interests must be resisted. This can best be accomplished through a partnership between education and organized dentistry where the lobbying power of the ADA is used to gain the resources education needs and where education, including research and patient care aspects of its mission, are enlisted in support of the practicing community.

Professional and community efforts to prevent morbidity and mortality from oral cancer

BACKGROUND

Oral and pharyngeal cancers cause significant morbidity and mortality, yet there has been little improvement in survival rates in the past 30 years. Because early diagnoses significantly increase survival rates, the authors summarize several approaches to educating and mobilizing the dental profession and the public about this problem. Clinicians are invited to initiate similar programs to catalyze change in their own communities.

METHODS

The authors found that many approaches have been used to define the problem and initiate change. These include surveys, focus groups, development of consortia, media programs, flyers, leaflets, prescription pads, legislation and professional endorsements.

RESULTS

In Maryland in 1996, only 20 percent of adults reported receiving an oral cancer examination, and most oral cancers were diagnosed at late stages by physicians, not dentists. Results of the public educational campaigns in the regions of New York/New Jersey and Maryland have not been formally evaluated, but there is a developing consensus that oral cancer diagnostic practices in the regions with active educational programs are increasing.

CONCLUSIONS

Coalitions or partnerships among individuals and organizations from government, academia, private practice, industry, the general community and the media can affect awareness about oral cancer prevention and early detection on a regional basis.

CLINICAL IMPLICATIONS

By increasing awareness of oral cancer among the dental profession and the public, earlier diagnosis of these cancers with consequent improved cure rates is likely. Providing oral cancer diagnostic services as a routine part of an oral examination also may motivate patients to visit the dentist at least once a year.

5% amlexanox oral paste, a new treatment for recurrent minor aphthous ulcers: I. Clinical demonstration of acceleration of healing and resolution of pain

5% Amlexanox oral paste (Aphthasol) was studied in four vehicle-controlled, randomized, double-blind, parallel group, multicenter, clinical studies involving 1335 subjects who had 1 to 3 aphthous ulcers less than 48 hours old at enrollment. Subjects applied study pastes directly to ulcers four times a day until ulcers healed or for the duration of the study, whichever occurred first. Ulcer size was measured by the investigator and pain was evaluated by the subject; the primary determinant of efficacy was the percentage of subjects with complete healing of ulcers and complete resolution of ulcer pain. The vehicle had marginal beneficial effects as would be expected from a covering material, but statistical significance over no treatment was inconsistent. However, these studies, both individually and collectively, clearly demonstrated in a highly significant and consistent manner that in comparison to both Vehicle and No Treatment 5% Amlexanox oral paste accelerates the resolution of pain and healing of aphthous ulcers.

5% amlexanox oral paste, a new treatment for recurrent minor aphthous ulcers: II. Pharmacokinetics and demonstration of clinical safety

The safety of 5% Amlexanox paste was demonstrated in the following clinical studies: vehicle-controlled safety and efficacy studies; dermal irritation and sensitization studies; single and multiple dose pharmacokinetic studies; and a 28-day in use safety study. Minimal adverse experiences were observed with the 991 subjects that were exposed to 5% Amlexanox paste. No significant irritation or sensitization was associated with 5% Amlexanox paste. Pharmacokinetic studies indicated that systemic levels of Amlexanox are most likely due to normal gastrointestinal absorption with only limited absorption directly through the ulcer. After a 100 mg dose of 5% Amlexanox paste the average maximum concentration of Amlexanox in the serum was 120 ng/ml, occurring 2.4 hours after application. The half-life for elimination of Amlexanox was 3.5 hours, and there was no evidence of accumulation with multiple applications. Overall, the data indicate that 5% Amlexanox paste (Aphthasol) is safe for the treatment of recurrent minor aphthous ulcers.

The effect of ketoprofen creams on periodontal disease in rhesus monkeys

Ketoprofen creams were evaluated for the treatment of periodontal disease in a placebo-controlled, double-blind study in the rhesus monkeys, Macaca mulatta. Two formulations containing ketoprofen (1%), with or without vitamin E, were evaluated against appropriate controls (8 monkeys per group). Two weeks prior to treatment, the animals received prophylaxis on only the left side of the mouth (spontaneous model). Selected teeth on the right side of the mouth were ligated (ligature model). The creams were administered to the gingiva once daily at a standard dose of 1.8 ml per monkey for 6 months. Clinical assessments were made 2 wk before initiation, at baseline and 1, 2, 3 and 6 months post-treatment. The clinical parameters included plaque formation, gingival redness, edema, bleeding on probing and Ramfjord Attachment Level measurements (RAL). Radiographs were taken at 2 wk before initiation, baseline and at 3 and 6 months post-treatment. Digital, subtraction radiography was used to measure vertical linear bone loss along the interproximal root surfaces of the left and right mandibular first molars. Gingival crevicular fluid (GCF) was collected for biochemical assays on PGE2, TxB2, LTB4, IL-1 beta and TNF alpha. There were no significant differences among groups with respect to gingival indices. Radiographic data demonstrated significant positive effects on bone activity in both groups treated with ketoprofen formulations with improvement over time in the ligature model (0.01 < or = p < or = 0.04). The placebo group exhibited bone loss of 1.96 +/- 0.48 and 1.40 +/- 0.56 mm per site at 3 and 6 months, respectively. The group treated with ketoprofen cream showed an apparent bone gain of 0.28 +/- 0.41 and 0.78 +/- 0.47 mm per site at 3 and 6 months, respectively. The group treated with ketoprofen cream containing vitamin E showed a mean bone loss of 0.41-0.48 mm per site at 3 months with improvement to an apparent bone gain of 0.31 +/- 0.44 mm per site at 6 months. The biochemical data demonstrated early and significant suppression of GCF-LTB4 by both ketoprofen formulations at 1 month, which preceded the significant suppression of GCF-PGE2 at 2 and 3 months in the ligature model (p < 0.003) and at 2 to 6 months in the spontaneous model (p < 0.02). We conclude that ketoprofen at 1% level in suitable topical vehicles can effectively inhibit GCF-LTB4 and GCF-PGE2 and positively alter alveolar bone activity in the ligature-induced model of periodontitis in the monkey.

Sulfadiazines reduce gingivitis and plaque formation in beagle dogs

The effect of zinc sulfadiazine (ZnSD) and silver sulfadiazine (AgSD) on reducing plaque formation and gingivitis was studied in 12 beagle dogs over a 14-week period. 12 beagle dogs were scaled, root planed and pumiced to bring them to a similar level of gingival health, prior to placing them on a diet of Purina Dog Chow softened with canned gravy and molasses to promote the build-up of plaque and the initiation of gingivitis. At the end of 8 weeks, the dogs were determined to have substantial bacterial plaque accumulation and apparent gingivitis. Thereafter, 4 dogs were treated 2 x daily with topical applications of 3% zinc sulfadiazine; 4 dogs were treated with 2% silver sulfadiazine while 4 dogs were treated with placebo gel serving as control over a 14-week treatment period. By week 2, the zinc and silver sulfadiazine dogs showed a significant decrease in gingival index which was maintained throughout the study. Additionally, by week 2, the % of sites with bleeding was also seen to decrease significantly in the experimental groups. The plaque index remained consistent in all 3 groups until week 6 when the 2 experimental groups indicated significant decrease in plaque accumulation as compared to controls. Probing depths were also seen to decrease significantly in the experimental groups after 10 weeks of therapy. The mean stain index was similar in all 3 groups of dogs throughout the study. Data indicate that both zinc and silver sulfadiazine inhibit plaque formation and reduce existing gingivitis in beagle dogs.

Sulfadiazines prevent plaque formation and gingivitis in beagles

The effect of zinc sulfadiazine (ZnSD) and silver sulfadiazine (AgSD) on developing plaque formation and gingivitis was studied in 12 beagle dogs over a 14-week period. Plaque and gingival indices were used to measure plaque formation and gingivitis. During a 2-wk baseline period each dog was brought to optimal gingival health with prophylaxis and tooth brushing. Thereafter, 4 dogs were treated twice daily with topical application of 3.0% zinc sulfadiazine; 4 dogs were treated with 2.0% silver sulfadiazine while 4 dogs treated with placebo gel served as controls over a 12-wk treatment period. At wk 2 of treatment, all three groups of dogs showed an increase in plaque build-up on their teeth from baseline. By wk 6, plaque accumulation on the teeth was significantly less in dogs treated with either ZnSD or AgSD compared to control dogs. At wk 2 of treatment, gingival inflammation was increased from baseline in all three groups. Thereafter, over the course of the 12-wk treatment period, gingival inflammation in the ZnSD and the AgSD treated dogs was significantly less than the placebo treated dogs. The data indicate that both ZnSD and AgSD inhibit developing plaque formation in beagles. This significant inhibition of plaque formation was accompanied by a significant reduction in gingival inflammation.

The effect of zinc chloride on the development of gingivitis in beagle dogs treated with cetylpyridinium chloride

Twenty-one beagle dogs were treated 12 times per week with either 0.05% cetylpyridinium chloride (CPC), 0.05% CPC plus 0.22% zinc chloride (ZnCl2), or water. Over seven wk, plaque and gingivitis were reduced by the CPC and CPC plus ZnCl 2 treatments, while stain and calculus were greatly reduced only by the CPC plus ZnCl2 treatment.

The relationship between the mobility of human teeth and their supracrestal fiber support

A method to study the relationship between the mobility of human teeth and their supracrestal fiber support was developed. The results of this study would indicate that: (1) The supracrestal fibers do not contribute significantly to the support of a normal premolar tooth. (2) As a human premolar tooth develops moderate to severe loss of osseous support, the relative contribution of the supracrestal fibers to the support of the tooth increases significantly.

Preserved scleral allografts in periodontal defects in man. II. Histological evaluation

1. The scleral grafts appeared to be well accepted as there were no signs of antigenicity or untoward reactions. 2. The gingival connective tissue, periodontal ligament and the periosteum were observed intertwined with sclera at the interface. 3. Sclera was invaded by host fibroblasts, capillaries, and appeared in some areas to be raplaced by a dense connective tissue. 4. Areas of cementogenesis could be observed in all specimens. 5. There were no signs of osteogenesis within the scleral grafts. 6. The alveolar crest appeared relatively nonreactive to sclera. 7. There were no signs of external root resorption or ankylosis. 8. Sclera may be able to be used to fill in osseous craters, other periodontal defects and as a scaffolding in conjunction with osseous grafts. This requires further investigation. 9. Sclera may possibly be used in areas where there was loss of gingival contour or need for ridge augmentation.