Effect of Chlorhexidine on the Hamster Cheek Pouch
tivity 10.25 ^tCi/mg and purity of 98.8% was supplied by Imperial Chemical Industries, L t d , Pharmaceuticals Division, Macclesteild, United Kingdom. Soluene-100 sample solubilizer and Instra-Gel scintillation cocktail were purchased from L K B - W a l l a c , T u r k u , Finland. A l l other chemicals were of analytical grade or of the highest available purity and were products of E . Merck A G , Darmstadt, Germany.
Microcirculation and Penetration Studies
2. Microcirculation Studies. The experiments were carried out with eight golden hamsters, weighing 110 to 130 gm. Each animal was anesthetized intraperitoneally 10 minutes before the experiment with Nembutal (70-80 mg/kg of body weight). The cheek pouch was everted and spread on the Teflon plate of the specimen holder of a vitalomicroscope, and fixed with a strip of double-face transparent tape.
by V. LUOSTARINEN * E . SÖDERLING † M . KNUUTTILA ‡ K
PAUNIO§
4
Observations were performed at 110 x magnification using an U O - 1 1 objective (Ernst Leitz G M B H , Wetzlar, Germany). The method of measuring flow velocity was based on a flying spot technique presented by Brånemark. The modification used in this study is the same as described by Scott et a l . Venules (ø 20 µ) were selected for targets.
C H L O R H E X I D I N E G L U C O N A T E is suggested as a drug to
be used in every day oral hygiene procedures. This recommendation should be based on studies approaching problems concerning the penetration of the drug and its possible effect on different tissues. Chlorhexidine gluconate, at a concentration of 0.2%, applied to intact or dekeratinized hamster cheek pouch tissue has not been found to induce microvascular disturbances in the underlying connective tissue. O n a defective cheek pouch surface, however, the test solution caused hemolysis, intravascular granulosytosis, and thrombus formation. Lindhe et a l . have suggested that the observations indicate the inability of chlorhexidine gluconate to penetrate undamaged oral epithelium.
5
6
The flow velocity was first followed for 4 minutes after the application of 2.0 µl of 0.45% N a C l solution. After this, 2 µ of 0.2% chlorhexidine gluconate (diluted with 0.45% N a C l ) was applied. The procedure was repeated after 20 and 29 minutes, again with 2 yl of 0.45% N a C l solution.
1
3. Penetration Studies. The cheek pouch of the anesthetized animal was everted and fixed on the plate as described above. [ C]chlorhexidine (0.2% water solution) was applied on the cheek pouch in 50-fil doses. The subsequent applications were made after the absorption of the solution (usually after 8 to 15-minute intervals). In order to avoid contamination of the labeled drug, the cheek pouch was carefully removed before the decapitation of the hamsters. Three separate experiments were conducted. Water, instead of chlorhexidine, was applied to the cheek pouches of the control animals. The pilot experiment ( A ) was carried out by applying 100 µl of chlorhexidine solution (2 x 50 fA). Two test and two control hamsters were sacrificed 30 minutes after the absorption of the solutions applied. The liver and kidneys were removed and samples for liquid scintillation counting were prepared using two different methods: a) One hundred and five hundred milligrams of both the liver and kidneys were dissolved for 16 hours at + 6 0 ° C in 1 ml qf Soluene-100. In order to decolorize the dissolved samples, 0.5 ml of 35% H 0 was added to the 500-mg samples for 60 minutes at 2 2 ° C . The excess H 0 was removed with acid. A l l samples were neutralized with N a O H before the counting in 10 ml of a scintillation coctail. The C-activity was determined in L K B - W a l l a c 81000 liquid scintillator (5 minutes per sample). 14
2
Davies and H u l l have shown that, after a single application of radiolabeled chlorhexidine digluconate, radioactivity could only be observed in the superficial epithelial layers of the oral tissues of beagle dogs. Somewhat different results, concerning the penetration of chlorhexidine through the oral mucosa of guinea pigs, have been presented by Haugen. Besides the fact that labeling was found in radioautographic studies throughout the epithelium, it was also found in the connective tissue, although less frequently than in the epithelium. The contradictory results of the above mentioned studies prompted the present investigation. The effect of chlorhexidine on the microcirculation of the intact cheek pouch of hamsters and the binding of the test solution to the cheek pouch and the appearance of labeled material in some tissues were studied. 3
1 - 3
MATERIALS
AND METHODS
1. Reagents and Their Sources. Chlorhexidine gluconate was obtained from I C I , Wilmslow, Cheshire, England. Chainlabeled [ -C]chlorhexidine (specific ac-
2
14
2
* Assistant Professor of Cariology. t Biochemist of the Department of Oral Biology. $ Associated Professor of Periodontics, University of Kuopio. §Professor of Periodontics, Institute of Dentistry, University of Turku, SF-20520 Turku 52, Finland.
2
14
421
2
422
Luostarinen,
Soderling,,
Knuuttila,
b) The liver and kidneys from the other test and con trol hamster were homogenized in water (1 g of tissue per 1 ml of water) using a Ultra-Turrax homogenizator. The proteins were precipitated with an equal volume of 20% trichloroacetic acid ( T C A ) solution. The precipi tates were washed with 10% T C A solution after centrifugation (10,000 rpm, for 10 minutes at + 4 0 ° C using a Sorwall-Superspeed centrifuge rotor SS-34). The supernatants from both procedures were combined and evaporated with warm air to approximately 0.5 ml. The resultant solutions were neutralized and the C-activity was determined as described above. 14
In the second experiment (B) 100 µl (2 x 5 0 µ l ) of the solution was applied. One of the two hamsters used in this experiment was sacrificed immediately after the absorption of the chlorhexidine solution; the other hamster was sacrificed 2 hours after absorption of the solution. The liver and kidney samples for liquid scintillation counting were prepared using mechanical homogenization and T C A treatment as described above. The pro teins of the serum and the cells of the blood collected from these hamsters were also precipitated with 10% T C A solution. The precipitates were washed once with 10% T C A solution; otherwise, the supernatants ob tained were treated for the counting as in the case of liver and kidneys. The C-activity of the cheek pouches was also determined. The removed pouches were washed twice on 0.05 M phosphate buffer, p H 7.2, and once in 1 ml of 0.1 N HC1 for 10 minutes. The r e activity of the HCl-solution, as well as that of the cheek pouch, after dissolving in 1.5 ml of Soluene-100 (for 16 hours, at + 6 0 ° C ) were counted as described previ ously. The third experiment (C) differed from the second experiment as follows: 200 µl of chlorhexidine solution was applied (4 x 50 µl) and the test hamster was killed 2 hours after the absorption of the test solution. 14
J. Periodontol. July, 1977
Paunio
Radioautographic analysis of the liver sections was performed as follows: sections of liver (once frozen) 5/xm thick were coated with N T B - 3 emulsion (Kodak Organic Chemicals, Rochester, N . Y . ) and exposed for 5 weeks. Staining was performed with hematoxylin and eosin. RESULTS
1. Effect of Chlorhexidine on the Flow Velocity. The application of 0.45% N a C l solution in the beginning of the experiment did not cause any noticeable change in the flow velocity (Fig. 1). However, immediately after the application of chlorhexidine, the flow velocity in creased remarkably. The increase was almost 50% over a period of 4 minutes. The values stayed at this high level for 13 minutes and then the flow velocity slowly returned to the initial level. The increase in the flow velocity was observed re peatedly after the application of chlorhexidine in all the experiments. 2. Penetration Studies. The radioautograms, pre pared in order to show the presence of labeled chlor hexidine or its degradation products, clearly showed labeled material in the liver sections (Fig. 2). Although quenching did not cause any problem (Experiment A a ) , it was not possible to detect counts in samples prepared with the aid of Soluene-100 from 100 mg of tissue. The samples prepared from 500 mg of tissue were quenched to such a great extent that no reliable results could be obtained. The homogenization and T C A treatment for the preparation of samples used in Experiment A b , led to results which showed that r e activity could be detected in the liver. Samples prepared from livers and kidneys which were removed immediately after the absorption showed no higher counts than the samples representing control material (Table 1). However, C-activity could be detected in the liver after 2 hours from the absorp14
FIGURE 1. Effect of0.2% chlorhexidine gluconate on the flow velocity. Two microliters of chlorhexidine gluconate were applied on the cheek pouch and the flow velocity (pum/s) in a venule was followed. Additions of 2 pi of 0.45% NaCl were made at the begin ning and again after 20 and 35 minutes.
Volume 48 Number 7
Effect 14
tion of 1 0 0 µL of [ C]chlorhexidine. The same result
of
Chlorhexidine
423
buffer. It was possible to extract about 1 0 % of this
was also found in experiment C (Table I). When the
absorbed drug with 0 . 1 N H Q solution. In spite of the
volume of chlorhexidine solution applied was twice as
TCA-extraction method used to prepare samples for
great as it was in experiment B , the
14
C-activity in
creased 3-fold. A correlation between the content of 14
[ C]chlorhexidine applied and the
14
scintillation counting, there was some variation in the values of the liver samples as can be seen in Table 1.
C-activity of sam DISCUSSION
ples prepared from the kidney could also be observed. 14
Only traces of C-activity could be observed in sam
The results of the present study indicate a clear effect
ples representing serum and blood cells. In experiments
of chlorhexidine gluconate on the flow velocity of the
14
B and C , approximately 2 0 % of the total C-activity
blood in the venules. This finding differs from the
applied was discovered in the cheek pouch washed with
observations made by Lindhe et a l . The explanation
1
FIGURE 2. Radioautograms of liver sections from two hamsters. A. Control hamster treated with 200 yl of distilled water. B. Experimental hamster treated with 200 yl of labeled chlorhexidine. Note the accumulation of labelled material in the darker cell areas. (x460). TABLE 1. Scintillation Counts of Liver and Kidney Tissues* Amount of solution applied to the cheek pouch Experiment B a) 100/ul of H 0 applied b) 100 fil of [ C]chlorhexidine appliedt c) 100 µl of [ ]chlorhexidine ap plied Experiment C a) 200/xl of H 0 applied b) 200 /Ltl of [ C]chlorhexidine ap plied
Decapitation time after application of the test solution (hours)
Liver counts/min/ 4 gm. of tissuet
Kidney counts/ min/1 gm of tis sued
184 177
126 292
2
1812
436
2 (no absorption) 2
86 6008
156 673
2 (no absorption) 0
2
14
14
2
14
* The values presented in the table are background corrected. t The livers of the test animals weighed approximately 4 gm. and the kidneys approximately 1 gm. $ Ten microliters of 0.2% [ C]chlorhexidine (specific activity 10.25 /^Ci/mg) counted in a 10-ml scintillation coctail gave about 25,000 counts/min. 14
424
Luostarinen,
Soderling,,
Knuuttila,
J. Periodontol. July, 1977
Paunio
for these conflicting results may be based on the meth ods used. In the present investigation it was possible to quantitate the flow velocity as micrometry per second. Chlorhexidine gluconate may have a direct or an indirect effect on the vascular system. The epithelium of the oral mucosa is capable of binding chlorhexidine gluconate very tightly. A l s o , chlorhexidine precipi tates p r o t e i n s . These two observations suggest an indirect effect of the drug on the vascular system be neath the epithelium. The fact that 20% of the applied labeled chlorhexidine will remain bound to the cheek pouch of the hamster, as was observed in the present investigation, supports the idea mentioned above.
hexidine gluconate can not, however, be based on the above results. The present investigation and earlier studies indicate the importance of focusing interest on questions of the reaction of tissues when additional clinical trials concerning the long-term use of chlorhexi dine are carried out. 1 0 s 1 1
7
8,9
O n the other hand, the observation made by Davies and H u l l and H a u g e n , that chlorhexidine can pene trate through the epithelium into the connective tissue, suggests a direct effect of the drug. The penetration of labeled chlorhexidine shown in the present investiga tion supports the latter concept of the effect of chlor hexidine on flow velocity. 2
3
Both chlorhexidine gluconate and labeled [ C]chlorhexidine affected the flow velocity in the same way. The velocity increased in both experiments immediately after the application of the drug. This observed phenomenon also indicates that the affecting component is chlorhexidine rather than the gluconate part of the drug. To avoid some methodological problems concerning the counting of small amounts of [ C]chlorhexidine in a large mass of tissue, homogenization coupled with TCA-treatment was carried out in order to release the labeled molecules. This procedure was based on the observations that chlorhexidine is easily bound tightly to proteins and that the drug is immediately released at pH l . The fact that only traces of the labeled drug could be observed in the blood can be explained if the total amount of applied C-activity and flow velocity are taken into consideration. The relatively few labeled molecules are quickly trapped from the blood stream into some part of the hamster's body, e.g. the liver, as has been shown by Magnuson and H e y d e n . A direct clinical implication of the above results can not be made. The investigation was carried out using a test animal and the observations made on the chlorhex idine do not necessarily stand for an unfavorable effect of the drug. The suggestions for long-term use of chlor 14
14
9
14
7
SUMMARY
The application of chlorhexidine gluconate on the intact cheek pouch of hamsters led to an immediate increase of flow velocity determined in venules beneath the epithelium. The application of [ C]chlorhexidine on the intact cheek pouch led to accumulation of la beled material in the liver and kidneys. Both findings indicate that penetration of the drug occurred through the epithelium of the cheek pouch. 14
REFERENCES
1. Lindhe, J . , Heyden, G . , Svanberg, G . , L o e , H . , and Rindom Schiott, C : Effect of local applications of chlorhexi dine on the oral mucosa of the hamster. / Periodont Res 5: 177,1970. 2. Davies, R . M . , and H u l l , P . S.: Plaque inhibition and distribution of chlorhexidine i n beagle dogs. / Periodont Res 8: (suppl. 12) 22, 1973. 3. Haugen, E . : Studies on penetration of chlorhexidine through the oral mucosa in guinea pigs. P h . D . thesis. Univer sity of Oslo, Oslo, 1974. 4. M a k i n e n , K . , Luostarinen, V . , Varrela, J . , R e k o l a , M . , and L u o m a , S.: Arginine aminopeptidase reactions to laser in vivo and in vitro. Biochem Med 13: 192, 1975. 5. Branemark: Vital microscopy of bone marrow in rab bit. Scand J Clin Lab Invest II: (suppl. 38) 1959. 6. Scott, D . Jr., Scheinin, A . , Karjalainen, S., and E d wall, L . : Influence of sympathetic nerve stimulation on flow velocity in pulpal vessels. Acta Odontol Scand 30: 2 7 7 , 1 9 7 2 . 7. Magnusson, B . , and Heyden, G . : Autoradiographic studies of C-chlorhexidine given orally in mice. J Periodont Res 8: (suppl. 12) 49, 1973. 8. Hjeljord, L . G . , Rölla, G . , and Bonesvoll, P . : Chlor hexidine protein interactions. J Periodont Res 8: (suppl. 12) 11, 1973. 9. Rölla, G . , and Melsen, B . : O n the mechanism of the plaque inhibition by chlorhexidine. J Dent Res 54B: 57, 1975. 10. Knuuttila, M . , Paunio, K . , and Mielityinen, H . : Ef fect of Chlorhexidine gluconate on acute nonmicrobial i n flammation reaction.J Periodontol, in press, 1977. 11. Paunio, K . , Knuuttila, M . , and Mielityinen, H . : Ef fect of chlorhexidine gluconate on the formation of experi mental granulation tissue.J Periodontol, in press, 1977. 14
63rd A N N U A L M E E T I N G of the AMERICAN A C A D E M Y OF PERIODONTOLOGY O C T O B E R 5-8, 1977 SHERATON-BOSTON HOTEL BOSTON, MASSACHUSETTS 16
WEDNESDAY, OCTOBER 5 7:30 a.m. O P E N I N G B R E A K F A S T / K E Y N O T E SPEAKER
9:00-2:00
Self-Assessment Program
9:00-12:00
ASSOCIATE MEMBER
17 18
PROGRAM
Chairman: Arnold Weisgold The Incorporation of Modern Gnathologic Principles into Advanced Restorative Den tistry. Frank Celenza 10:00-12:00 1.30-4:30 p.m.
1:35 2:20 3:15 4:00 1:30-4:30
19 20
O P E N I N G BUSINESS SESSION C R I T E R I A F O R SUCCESS I N PERI ODONTAL THERAPY
21 22
Chairman: Gerald Kramer Is It Attainable? Timothy J. O'Leary Can We Measure It? Gerald M. Bowers Is It Communicable? James A . Tobias Open Discussion BALINT ORBAN COMPETITION
MEMORIAL
23 24
PRIZE
25
Chairman: A . Baumhammers 4:30 6.30
26
DISTRICT C A U C U S E S F R I E N D S H I P H O U R (Cash Bar)
27
THURSDAY, OCTOBER 6
9:00-4:30
Self Assessment Program
28
8:30-12:00 noon C U R R E N T S T A T E O F T H E A R T O F P E R IODONTICS
1:30-5:15 p.m. 8:45 9:30 10:15 10:30 11:15 1:30 2:15 3:00 3:15
4:45
1:30-4:30 p.m.
(Are we overtreating or undertreating peri odontal disease?) Chairman: Claude Nabers Sigurd Ramfjord Henry Goldman Break Lawrence Haskins Harley Sullivan John Prichard Jan Lindhe Break Panel Dialogue (Each panelist will be allo cated ten minutes to question other panelists and subsequently, five minutes for summary/ comments.) Open Discussion
9:00-2:00
Self-Assessment Program ASSOCIATE MEMBER
Chairman: Jay Seibert Rationale for the Use of Antibiotics in the Prevention and Treatment of Periodontal Dis eases. Sigmund Socransky 2:20 Use of Antibiotics in the Management of Peri odontal Disease. Robert Genco 3:15 Clinical Application of Antibiotics to Peri odontal Surgery. Samuel V. Holroyd 4:00 Open Discussion 1:30-4:30 p.m. P R O J E C T E D C L I N I C S (14 sessions, 7 run ning concurrently at 1:30 and 3:15) Chairman: H . Dalton Conner Room 1 1:30 Soft Tissue Grafts. Gloria James Kerry 3:15 Flap Procedures and Suturing Techniques. Eiji Funakoshi Room 2 1:30 Vitreous Carbon Implants. Roland M. Meffert 3:15 Histologic Assessment of Scleral Grafts. Mick R. Dragoo Room 3 1:30 Root Coverage Technique for Teeth with De hiscences. David H. Dinner 3:15 Clinical Reattachment by i n s i t u Root Demineralization. Alton A . Register Room 4 1:30 Incision Design. Leonard S. Tibbetts 3:15 Bone Grafting Principles in Oral Reconstruc tion as it Relates to Maxillo-facial Surgery. Donald Booth Room 5 1:30 Method of Nutritional Analysis and Prescrip tion. G. Kent Powers 3:15 Management of Fear in the Periodontal Pa tient. W. Kent Keith Room 6 1:30 Re-establishment and Preservation of Muti lated Posterior Occlusion Based on Periodon tal Dictates. Daulton J. Keith Jr., Robert E. Roe 3:15 Prosthetic Management of the Furcation Area. Michael Rubin Room 7 1:30 Altering Crestal Level Prior to Definitive Pocket Elimination. Barry D. Wagenberg 3:15 Updating Techniques in Contiguous Autoge nous Bone Transfer. Sol J. Ewen
PROGRAM
Chairman: Arnold S. Weisgold Ceramo-Metal Restorations. R. Sheldon Stein 12:00 noon
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
T H E R O L E O F ANTIBIOTICS I N PERI ODONTAL THERAPY
1:35
FRIDAY, OCTOBER 7 8:45 a m. A S S O C I A T E M E M B E R M E E T I N G 9:00-12:00 A N N U A L BUSINESS SESSION 10:00-12:00
Donald F. Adams —Extended Function Auxi liaries in Periodontal Practice John P. Derdivanis — All You Ever Wanted to Know About Insurance Jerome S. Zackin — Dental Prepayment — Don't Get Ulcers, Give Them Herman Corn — An Assessment of 25 Years in the Practice of Periodontics Stanley R. Saxe — Managing the Problem Fur cation Harry Staffileno Jr. —Flap Modification and Suturing Techniques Marvin M. Sugarman — Discuss Your Acad emy—An Open Forum James Y. O'Bannon — Discuss Your Acad emy—An Open Forum Malbern N. Wilderman — Periodontal Surgery Wound Healing Ira L . Cantner — Significance of Dento-gingival Junction in Periodontal Prosthesis Timothy F. Geraci —Ortho Movement of Teeth into Infrabony Defects — Histologic Re port Garry M. Miller — Utilization of Soft Tissue Autografts Sebastian Cianco — Periodontic — Endodontic Relationship
LUNCHEON FOR LEARNING
Sanford C. Frumker—Occlusion Henry S. Brenman — Physiology of Occlusion Nicholas M. Dello Russo —Upper Anterior Periodontal Therapy James A . McMullen —The Effect of Diabetes when Treating Periodontal Disease Frank E . Beube—Treatment Planning Corre lating Periodontal and Restorative Dentistry Carole N. Hildebrand — Why Does the Gen eral Practitioner Not Feel Challenged by Peri odontal Disease? Irving B. Stern—The Management of Prob lems in Initial Preparation Thomas R. Tempel — Leukocyte Deficiencies & Periodontal Disease Marvin Simring —Therapeutic Disocclusion Lawrence F. Halpert —A Discussion of Satel lite Offices Frank T. Scott — Practice Administration Anthony C. Ruggerio — Intravenous Sedation Michael G. Newman — Microbiology of Peri odontal Disease R. Earl Robinson —A Long Term Evaluation of Bone Addition Procedures Daniel A. Grant — The Progression of Gingivi tis to Periodontitis
6:30
PRESIDENT'S C L A M B A K E
taurant) 425
(Pier 4 Res
426 rence Cohen Twin B i l l Periodontal Considerations with Overdentures. James Thiel Periodontal Considerations for Implant Den tistry. Donald M. Keene Clinical Management of Periodontal Disease in Children and Adolescents. Paul Baer, Shel don Benjamin Office and Practice Management Seminars. Charles Bress, Herman Cantor, Albert Salkind, Harold DeHaven, Ronald Fabrick, Jack Freiman, Michael S. Grossman, James McClenahan/Randy Vitek, Paul Rhodes Symposium on Hard Tissue Formation and Resorption in Periodontal Disease. Alfred Weinstock, Max Goodson, Lawrence Raisz Stress in Dental Practice; Why Dentists Com mit Suicide; Coping with Stress and Hyperten sion; The Relaxation Response. Richard Sword, Herbert Benson Sequential Management of Provisional Resto ration in Periodontal Prosthesis (a) as an Ad junct to Periodontal Therapy and (b) as Appli cable to the Permanent Restoration. Arnold Weisgold, Howard Skurow
SATURDAY, OCTOBER 8
(9) 8:30-1:00
(1)
(2) (3)
(4) (5) (6) (7) (8)
CONTINUING EDUCATION
COURSES
Chairman: Morris P. Ruben American Heart Association Course in Basic Life Support; Cardiopulmonary Resuscitation. Emerson Thomas (This course only, 8:00 a . m . to 2 : 0 0 p . m . ) Occlusal Adjustment of Natural Dentition. Hyman Smukler, Abraham Haddad, Waldyr Janson Allografts in Periodontal Reconstructive Sur gery—Skin, Sclera, and Bone. Raymond Yukna, Jules Klingsberg, Mick Dragoo, Robert Koch Limitations of Osseous Reconstructive Tech niques in Periodontics. Robert Schallhorn, Stuart Froum, Marvin Rosenberg Periodontal Problems and Considerations in Orthodontic Treatment. Roger Wise, Gary Reiser Biologic Rationale and Surgical Methods of Soft Tissue Reconstruction. Anthony Melcher, William Ammons Importance of Nutrition in Patient Care. Louis Fillios, Frederic Stare, Sanford Miller, William Steffee Medical Aspects of Periodontal Care. Law
(10) (11)
(12) (13)
(14)
9:00-l 2:00
RESEARCH FORUM
Chairman: Herbert Oshrain
IMPORTANT NOTICE T O MEMBERS
Chapter I, Section 5 of the Bylaws of the American Academy of Periodontology states: "Active and Associate members shall be required to attend at least one scientific session during each three-year period. "Attendance shall not be required of other classes of members. "In the event of illness or other extenuating circumstances, Active and Associate members may petition the Executive Council by letter through the Secretary for waiver of attendance requirements. Such an appeal shall be addressed to the Secretary not later than 60 days after the scientific session at which attendance may otherwise have been required."
Abstracts ORTHOPANTOMOGRAPHIC ASSESSMENT OF THE WIDTH OF ATTACHED GINGIVA
Talari, A . , and Ainamo, J. J Periodont Res 11: 177, July, 1976. Using a short piece of metal wire, attached to the tooth and gingiva by a strip of Squibb's Orahesive Dental Bandage, the muco gingival junction can be visualized on an orthopantomographic film. Thus, a method was developed for assessment of the width of at tached gingiva. Measurements, to the nearest millimeter, were made for each tooth from the mucogingival to the cementoenamel junction of 10 randomly selected adults. Follow-up examinations at 1 week and 2 month intervals were made to determine the reproducibility of the procedures in five adults. The total deviation caused by repeating the procedure was 0.7 mm, which was less than the one millimeter unit of measurement. Institute of Dentistry, University of Helsinki, F a b i a n i n k a t u 2 4 , S F - 0 0 1 0 0 Helsinki 1 0 , Finland. Dr. Alan W . Metzger DEVELOPMENT OF PLAQUE ON ENAMEL
Tinanoff, N., Gross, A . , and Brady J. M . J Periodont Res 11: 197, 1976. Plaque formation was studied using a technique whereby cylinders of surface enamel were placed in a maxillary Hawley appliance which was worn up to 7 days. Results from 75 cylinders kept in the mouth from 15 minutes to 7 days showed that a thin organic film covered the surface of the enamel after 1 hour. Microscopic studies of 2-day-old plaque revealed desquamated epithelial cells and bacteria adsorbed
to the enamel. Transmission electron microscopy showed different bacteria adjacent to the enamel than those adsorbed to the enamel surface. An extracellular material appeared to be excreted from the adsorbed altered bacteria. Desquamated epithelial cells were less abundant in mature plaque than in 1 and 2 day plaque samples. Microbiologic findings showed that the initial bacterial layer con sisted of cocci, and the flora changed to rods and filaments in the 7 day samples. U. S. Army Institute of D e n t a l Research, Walter Reed Army Medical Center, Washington, D.C. 20012. Dr. Alan W. Metzger
SALIVARY I G G AND I G A BEFORE AND AFTER PERIODONTAL THERAPY. A PRELIMINARY REPORT
Basu, M. K., Glenwright, H . D., Fox, E . C , and Becker, J. F. / Periodont Res 11: 226, July, 1976. Samples of the whole saliva of 12 patients, ages 20 to 43 with periodontal disease, were analyzed for immunoglobulins G and A . Local production of immunoglobulins during the development of periodontal disease previously had been shown to be characterized by a predominating synthesis of IgG. In the 12 patients of the current study IgG concentration was higher, and the IgA concentration lower than in clinically normal individuals. Six months after oral hygiene therapy and periodontal surgery, saliva samples were analyzed again and the concentration of the immunoglobulins was comparable with those of clinically normal mouths. Department of O r a l Pathology, The D e n t a l School, St. Chad's Queensway, B i r m i n g h a m B 6 4 6NN England. Dr. Rory O'Neill
tivity 10.25 ^tCi/mg and purity of 98.8% was supplied by Imperial Chemical Industries, L t d , Pharmaceuticals Division, Macclesteild, United Kingdom. Soluene-100 sample solubilizer and Instra-Gel scintillation cocktail were purchased from L K B - W a l l a c , T u r k u , Finland. A l l other chemicals were of analytical grade or of the highest available purity and were products of E . Merck A G , Darmstadt, Germany.
Microcirculation and Penetration Studies
2. Microcirculation Studies. The experiments were carried out with eight golden hamsters, weighing 110 to 130 gm. Each animal was anesthetized intraperitoneally 10 minutes before the experiment with Nembutal (70-80 mg/kg of body weight). The cheek pouch was everted and spread on the Teflon plate of the specimen holder of a vitalomicroscope, and fixed with a strip of double-face transparent tape.
by V. LUOSTARINEN * E . SÖDERLING † M . KNUUTTILA ‡ K
PAUNIO§
4
Observations were performed at 110 x magnification using an U O - 1 1 objective (Ernst Leitz G M B H , Wetzlar, Germany). The method of measuring flow velocity was based on a flying spot technique presented by Brånemark. The modification used in this study is the same as described by Scott et a l . Venules (ø 20 µ) were selected for targets.
C H L O R H E X I D I N E G L U C O N A T E is suggested as a drug to
be used in every day oral hygiene procedures. This recommendation should be based on studies approaching problems concerning the penetration of the drug and its possible effect on different tissues. Chlorhexidine gluconate, at a concentration of 0.2%, applied to intact or dekeratinized hamster cheek pouch tissue has not been found to induce microvascular disturbances in the underlying connective tissue. O n a defective cheek pouch surface, however, the test solution caused hemolysis, intravascular granulosytosis, and thrombus formation. Lindhe et a l . have suggested that the observations indicate the inability of chlorhexidine gluconate to penetrate undamaged oral epithelium.
5
6
The flow velocity was first followed for 4 minutes after the application of 2.0 µl of 0.45% N a C l solution. After this, 2 µ of 0.2% chlorhexidine gluconate (diluted with 0.45% N a C l ) was applied. The procedure was repeated after 20 and 29 minutes, again with 2 yl of 0.45% N a C l solution.
1
3. Penetration Studies. The cheek pouch of the anesthetized animal was everted and fixed on the plate as described above. [ C]chlorhexidine (0.2% water solution) was applied on the cheek pouch in 50-fil doses. The subsequent applications were made after the absorption of the solution (usually after 8 to 15-minute intervals). In order to avoid contamination of the labeled drug, the cheek pouch was carefully removed before the decapitation of the hamsters. Three separate experiments were conducted. Water, instead of chlorhexidine, was applied to the cheek pouches of the control animals. The pilot experiment ( A ) was carried out by applying 100 µl of chlorhexidine solution (2 x 50 fA). Two test and two control hamsters were sacrificed 30 minutes after the absorption of the solutions applied. The liver and kidneys were removed and samples for liquid scintillation counting were prepared using two different methods: a) One hundred and five hundred milligrams of both the liver and kidneys were dissolved for 16 hours at + 6 0 ° C in 1 ml qf Soluene-100. In order to decolorize the dissolved samples, 0.5 ml of 35% H 0 was added to the 500-mg samples for 60 minutes at 2 2 ° C . The excess H 0 was removed with acid. A l l samples were neutralized with N a O H before the counting in 10 ml of a scintillation coctail. The C-activity was determined in L K B - W a l l a c 81000 liquid scintillator (5 minutes per sample). 14
2
Davies and H u l l have shown that, after a single application of radiolabeled chlorhexidine digluconate, radioactivity could only be observed in the superficial epithelial layers of the oral tissues of beagle dogs. Somewhat different results, concerning the penetration of chlorhexidine through the oral mucosa of guinea pigs, have been presented by Haugen. Besides the fact that labeling was found in radioautographic studies throughout the epithelium, it was also found in the connective tissue, although less frequently than in the epithelium. The contradictory results of the above mentioned studies prompted the present investigation. The effect of chlorhexidine on the microcirculation of the intact cheek pouch of hamsters and the binding of the test solution to the cheek pouch and the appearance of labeled material in some tissues were studied. 3
1 - 3
MATERIALS
AND METHODS
1. Reagents and Their Sources. Chlorhexidine gluconate was obtained from I C I , Wilmslow, Cheshire, England. Chainlabeled [ -C]chlorhexidine (specific ac-
2
14
2
* Assistant Professor of Cariology. t Biochemist of the Department of Oral Biology. $ Associated Professor of Periodontics, University of Kuopio. §Professor of Periodontics, Institute of Dentistry, University of Turku, SF-20520 Turku 52, Finland.
2
14
421
2
422
Luostarinen,
Soderling,,
Knuuttila,
b) The liver and kidneys from the other test and con trol hamster were homogenized in water (1 g of tissue per 1 ml of water) using a Ultra-Turrax homogenizator. The proteins were precipitated with an equal volume of 20% trichloroacetic acid ( T C A ) solution. The precipi tates were washed with 10% T C A solution after centrifugation (10,000 rpm, for 10 minutes at + 4 0 ° C using a Sorwall-Superspeed centrifuge rotor SS-34). The supernatants from both procedures were combined and evaporated with warm air to approximately 0.5 ml. The resultant solutions were neutralized and the C-activity was determined as described above. 14
In the second experiment (B) 100 µl (2 x 5 0 µ l ) of the solution was applied. One of the two hamsters used in this experiment was sacrificed immediately after the absorption of the chlorhexidine solution; the other hamster was sacrificed 2 hours after absorption of the solution. The liver and kidney samples for liquid scintillation counting were prepared using mechanical homogenization and T C A treatment as described above. The pro teins of the serum and the cells of the blood collected from these hamsters were also precipitated with 10% T C A solution. The precipitates were washed once with 10% T C A solution; otherwise, the supernatants ob tained were treated for the counting as in the case of liver and kidneys. The C-activity of the cheek pouches was also determined. The removed pouches were washed twice on 0.05 M phosphate buffer, p H 7.2, and once in 1 ml of 0.1 N HC1 for 10 minutes. The r e activity of the HCl-solution, as well as that of the cheek pouch, after dissolving in 1.5 ml of Soluene-100 (for 16 hours, at + 6 0 ° C ) were counted as described previ ously. The third experiment (C) differed from the second experiment as follows: 200 µl of chlorhexidine solution was applied (4 x 50 µl) and the test hamster was killed 2 hours after the absorption of the test solution. 14
J. Periodontol. July, 1977
Paunio
Radioautographic analysis of the liver sections was performed as follows: sections of liver (once frozen) 5/xm thick were coated with N T B - 3 emulsion (Kodak Organic Chemicals, Rochester, N . Y . ) and exposed for 5 weeks. Staining was performed with hematoxylin and eosin. RESULTS
1. Effect of Chlorhexidine on the Flow Velocity. The application of 0.45% N a C l solution in the beginning of the experiment did not cause any noticeable change in the flow velocity (Fig. 1). However, immediately after the application of chlorhexidine, the flow velocity in creased remarkably. The increase was almost 50% over a period of 4 minutes. The values stayed at this high level for 13 minutes and then the flow velocity slowly returned to the initial level. The increase in the flow velocity was observed re peatedly after the application of chlorhexidine in all the experiments. 2. Penetration Studies. The radioautograms, pre pared in order to show the presence of labeled chlor hexidine or its degradation products, clearly showed labeled material in the liver sections (Fig. 2). Although quenching did not cause any problem (Experiment A a ) , it was not possible to detect counts in samples prepared with the aid of Soluene-100 from 100 mg of tissue. The samples prepared from 500 mg of tissue were quenched to such a great extent that no reliable results could be obtained. The homogenization and T C A treatment for the preparation of samples used in Experiment A b , led to results which showed that r e activity could be detected in the liver. Samples prepared from livers and kidneys which were removed immediately after the absorption showed no higher counts than the samples representing control material (Table 1). However, C-activity could be detected in the liver after 2 hours from the absorp14
FIGURE 1. Effect of0.2% chlorhexidine gluconate on the flow velocity. Two microliters of chlorhexidine gluconate were applied on the cheek pouch and the flow velocity (pum/s) in a venule was followed. Additions of 2 pi of 0.45% NaCl were made at the begin ning and again after 20 and 35 minutes.
Volume 48 Number 7
Effect 14
tion of 1 0 0 µL of [ C]chlorhexidine. The same result
of
Chlorhexidine
423
buffer. It was possible to extract about 1 0 % of this
was also found in experiment C (Table I). When the
absorbed drug with 0 . 1 N H Q solution. In spite of the
volume of chlorhexidine solution applied was twice as
TCA-extraction method used to prepare samples for
great as it was in experiment B , the
14
C-activity in
creased 3-fold. A correlation between the content of 14
[ C]chlorhexidine applied and the
14
scintillation counting, there was some variation in the values of the liver samples as can be seen in Table 1.
C-activity of sam DISCUSSION
ples prepared from the kidney could also be observed. 14
Only traces of C-activity could be observed in sam
The results of the present study indicate a clear effect
ples representing serum and blood cells. In experiments
of chlorhexidine gluconate on the flow velocity of the
14
B and C , approximately 2 0 % of the total C-activity
blood in the venules. This finding differs from the
applied was discovered in the cheek pouch washed with
observations made by Lindhe et a l . The explanation
1
FIGURE 2. Radioautograms of liver sections from two hamsters. A. Control hamster treated with 200 yl of distilled water. B. Experimental hamster treated with 200 yl of labeled chlorhexidine. Note the accumulation of labelled material in the darker cell areas. (x460). TABLE 1. Scintillation Counts of Liver and Kidney Tissues* Amount of solution applied to the cheek pouch Experiment B a) 100/ul of H 0 applied b) 100 fil of [ C]chlorhexidine appliedt c) 100 µl of [ ]chlorhexidine ap plied Experiment C a) 200/xl of H 0 applied b) 200 /Ltl of [ C]chlorhexidine ap plied
Decapitation time after application of the test solution (hours)
Liver counts/min/ 4 gm. of tissuet
Kidney counts/ min/1 gm of tis sued
184 177
126 292
2
1812
436
2 (no absorption) 2
86 6008
156 673
2 (no absorption) 0
2
14
14
2
14
* The values presented in the table are background corrected. t The livers of the test animals weighed approximately 4 gm. and the kidneys approximately 1 gm. $ Ten microliters of 0.2% [ C]chlorhexidine (specific activity 10.25 /^Ci/mg) counted in a 10-ml scintillation coctail gave about 25,000 counts/min. 14
424
Luostarinen,
Soderling,,
Knuuttila,
J. Periodontol. July, 1977
Paunio
for these conflicting results may be based on the meth ods used. In the present investigation it was possible to quantitate the flow velocity as micrometry per second. Chlorhexidine gluconate may have a direct or an indirect effect on the vascular system. The epithelium of the oral mucosa is capable of binding chlorhexidine gluconate very tightly. A l s o , chlorhexidine precipi tates p r o t e i n s . These two observations suggest an indirect effect of the drug on the vascular system be neath the epithelium. The fact that 20% of the applied labeled chlorhexidine will remain bound to the cheek pouch of the hamster, as was observed in the present investigation, supports the idea mentioned above.
hexidine gluconate can not, however, be based on the above results. The present investigation and earlier studies indicate the importance of focusing interest on questions of the reaction of tissues when additional clinical trials concerning the long-term use of chlorhexi dine are carried out. 1 0 s 1 1
7
8,9
O n the other hand, the observation made by Davies and H u l l and H a u g e n , that chlorhexidine can pene trate through the epithelium into the connective tissue, suggests a direct effect of the drug. The penetration of labeled chlorhexidine shown in the present investiga tion supports the latter concept of the effect of chlor hexidine on flow velocity. 2
3
Both chlorhexidine gluconate and labeled [ C]chlorhexidine affected the flow velocity in the same way. The velocity increased in both experiments immediately after the application of the drug. This observed phenomenon also indicates that the affecting component is chlorhexidine rather than the gluconate part of the drug. To avoid some methodological problems concerning the counting of small amounts of [ C]chlorhexidine in a large mass of tissue, homogenization coupled with TCA-treatment was carried out in order to release the labeled molecules. This procedure was based on the observations that chlorhexidine is easily bound tightly to proteins and that the drug is immediately released at pH l . The fact that only traces of the labeled drug could be observed in the blood can be explained if the total amount of applied C-activity and flow velocity are taken into consideration. The relatively few labeled molecules are quickly trapped from the blood stream into some part of the hamster's body, e.g. the liver, as has been shown by Magnuson and H e y d e n . A direct clinical implication of the above results can not be made. The investigation was carried out using a test animal and the observations made on the chlorhex idine do not necessarily stand for an unfavorable effect of the drug. The suggestions for long-term use of chlor 14
14
9
14
7
SUMMARY
The application of chlorhexidine gluconate on the intact cheek pouch of hamsters led to an immediate increase of flow velocity determined in venules beneath the epithelium. The application of [ C]chlorhexidine on the intact cheek pouch led to accumulation of la beled material in the liver and kidneys. Both findings indicate that penetration of the drug occurred through the epithelium of the cheek pouch. 14
REFERENCES
1. Lindhe, J . , Heyden, G . , Svanberg, G . , L o e , H . , and Rindom Schiott, C : Effect of local applications of chlorhexi dine on the oral mucosa of the hamster. / Periodont Res 5: 177,1970. 2. Davies, R . M . , and H u l l , P . S.: Plaque inhibition and distribution of chlorhexidine i n beagle dogs. / Periodont Res 8: (suppl. 12) 22, 1973. 3. Haugen, E . : Studies on penetration of chlorhexidine through the oral mucosa in guinea pigs. P h . D . thesis. Univer sity of Oslo, Oslo, 1974. 4. M a k i n e n , K . , Luostarinen, V . , Varrela, J . , R e k o l a , M . , and L u o m a , S.: Arginine aminopeptidase reactions to laser in vivo and in vitro. Biochem Med 13: 192, 1975. 5. Branemark: Vital microscopy of bone marrow in rab bit. Scand J Clin Lab Invest II: (suppl. 38) 1959. 6. Scott, D . Jr., Scheinin, A . , Karjalainen, S., and E d wall, L . : Influence of sympathetic nerve stimulation on flow velocity in pulpal vessels. Acta Odontol Scand 30: 2 7 7 , 1 9 7 2 . 7. Magnusson, B . , and Heyden, G . : Autoradiographic studies of C-chlorhexidine given orally in mice. J Periodont Res 8: (suppl. 12) 49, 1973. 8. Hjeljord, L . G . , Rölla, G . , and Bonesvoll, P . : Chlor hexidine protein interactions. J Periodont Res 8: (suppl. 12) 11, 1973. 9. Rölla, G . , and Melsen, B . : O n the mechanism of the plaque inhibition by chlorhexidine. J Dent Res 54B: 57, 1975. 10. Knuuttila, M . , Paunio, K . , and Mielityinen, H . : Ef fect of Chlorhexidine gluconate on acute nonmicrobial i n flammation reaction.J Periodontol, in press, 1977. 11. Paunio, K . , Knuuttila, M . , and Mielityinen, H . : Ef fect of chlorhexidine gluconate on the formation of experi mental granulation tissue.J Periodontol, in press, 1977. 14
63rd A N N U A L M E E T I N G of the AMERICAN A C A D E M Y OF PERIODONTOLOGY O C T O B E R 5-8, 1977 SHERATON-BOSTON HOTEL BOSTON, MASSACHUSETTS 16
WEDNESDAY, OCTOBER 5 7:30 a.m. O P E N I N G B R E A K F A S T / K E Y N O T E SPEAKER
9:00-2:00
Self-Assessment Program
9:00-12:00
ASSOCIATE MEMBER
17 18
PROGRAM
Chairman: Arnold Weisgold The Incorporation of Modern Gnathologic Principles into Advanced Restorative Den tistry. Frank Celenza 10:00-12:00 1.30-4:30 p.m.
1:35 2:20 3:15 4:00 1:30-4:30
19 20
O P E N I N G BUSINESS SESSION C R I T E R I A F O R SUCCESS I N PERI ODONTAL THERAPY
21 22
Chairman: Gerald Kramer Is It Attainable? Timothy J. O'Leary Can We Measure It? Gerald M. Bowers Is It Communicable? James A . Tobias Open Discussion BALINT ORBAN COMPETITION
MEMORIAL
23 24
PRIZE
25
Chairman: A . Baumhammers 4:30 6.30
26
DISTRICT C A U C U S E S F R I E N D S H I P H O U R (Cash Bar)
27
THURSDAY, OCTOBER 6
9:00-4:30
Self Assessment Program
28
8:30-12:00 noon C U R R E N T S T A T E O F T H E A R T O F P E R IODONTICS
1:30-5:15 p.m. 8:45 9:30 10:15 10:30 11:15 1:30 2:15 3:00 3:15
4:45
1:30-4:30 p.m.
(Are we overtreating or undertreating peri odontal disease?) Chairman: Claude Nabers Sigurd Ramfjord Henry Goldman Break Lawrence Haskins Harley Sullivan John Prichard Jan Lindhe Break Panel Dialogue (Each panelist will be allo cated ten minutes to question other panelists and subsequently, five minutes for summary/ comments.) Open Discussion
9:00-2:00
Self-Assessment Program ASSOCIATE MEMBER
Chairman: Jay Seibert Rationale for the Use of Antibiotics in the Prevention and Treatment of Periodontal Dis eases. Sigmund Socransky 2:20 Use of Antibiotics in the Management of Peri odontal Disease. Robert Genco 3:15 Clinical Application of Antibiotics to Peri odontal Surgery. Samuel V. Holroyd 4:00 Open Discussion 1:30-4:30 p.m. P R O J E C T E D C L I N I C S (14 sessions, 7 run ning concurrently at 1:30 and 3:15) Chairman: H . Dalton Conner Room 1 1:30 Soft Tissue Grafts. Gloria James Kerry 3:15 Flap Procedures and Suturing Techniques. Eiji Funakoshi Room 2 1:30 Vitreous Carbon Implants. Roland M. Meffert 3:15 Histologic Assessment of Scleral Grafts. Mick R. Dragoo Room 3 1:30 Root Coverage Technique for Teeth with De hiscences. David H. Dinner 3:15 Clinical Reattachment by i n s i t u Root Demineralization. Alton A . Register Room 4 1:30 Incision Design. Leonard S. Tibbetts 3:15 Bone Grafting Principles in Oral Reconstruc tion as it Relates to Maxillo-facial Surgery. Donald Booth Room 5 1:30 Method of Nutritional Analysis and Prescrip tion. G. Kent Powers 3:15 Management of Fear in the Periodontal Pa tient. W. Kent Keith Room 6 1:30 Re-establishment and Preservation of Muti lated Posterior Occlusion Based on Periodon tal Dictates. Daulton J. Keith Jr., Robert E. Roe 3:15 Prosthetic Management of the Furcation Area. Michael Rubin Room 7 1:30 Altering Crestal Level Prior to Definitive Pocket Elimination. Barry D. Wagenberg 3:15 Updating Techniques in Contiguous Autoge nous Bone Transfer. Sol J. Ewen
PROGRAM
Chairman: Arnold S. Weisgold Ceramo-Metal Restorations. R. Sheldon Stein 12:00 noon
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
T H E R O L E O F ANTIBIOTICS I N PERI ODONTAL THERAPY
1:35
FRIDAY, OCTOBER 7 8:45 a m. A S S O C I A T E M E M B E R M E E T I N G 9:00-12:00 A N N U A L BUSINESS SESSION 10:00-12:00
Donald F. Adams —Extended Function Auxi liaries in Periodontal Practice John P. Derdivanis — All You Ever Wanted to Know About Insurance Jerome S. Zackin — Dental Prepayment — Don't Get Ulcers, Give Them Herman Corn — An Assessment of 25 Years in the Practice of Periodontics Stanley R. Saxe — Managing the Problem Fur cation Harry Staffileno Jr. —Flap Modification and Suturing Techniques Marvin M. Sugarman — Discuss Your Acad emy—An Open Forum James Y. O'Bannon — Discuss Your Acad emy—An Open Forum Malbern N. Wilderman — Periodontal Surgery Wound Healing Ira L . Cantner — Significance of Dento-gingival Junction in Periodontal Prosthesis Timothy F. Geraci —Ortho Movement of Teeth into Infrabony Defects — Histologic Re port Garry M. Miller — Utilization of Soft Tissue Autografts Sebastian Cianco — Periodontic — Endodontic Relationship
LUNCHEON FOR LEARNING
Sanford C. Frumker—Occlusion Henry S. Brenman — Physiology of Occlusion Nicholas M. Dello Russo —Upper Anterior Periodontal Therapy James A . McMullen —The Effect of Diabetes when Treating Periodontal Disease Frank E . Beube—Treatment Planning Corre lating Periodontal and Restorative Dentistry Carole N. Hildebrand — Why Does the Gen eral Practitioner Not Feel Challenged by Peri odontal Disease? Irving B. Stern—The Management of Prob lems in Initial Preparation Thomas R. Tempel — Leukocyte Deficiencies & Periodontal Disease Marvin Simring —Therapeutic Disocclusion Lawrence F. Halpert —A Discussion of Satel lite Offices Frank T. Scott — Practice Administration Anthony C. Ruggerio — Intravenous Sedation Michael G. Newman — Microbiology of Peri odontal Disease R. Earl Robinson —A Long Term Evaluation of Bone Addition Procedures Daniel A. Grant — The Progression of Gingivi tis to Periodontitis
6:30
PRESIDENT'S C L A M B A K E
taurant) 425
(Pier 4 Res
426 rence Cohen Twin B i l l Periodontal Considerations with Overdentures. James Thiel Periodontal Considerations for Implant Den tistry. Donald M. Keene Clinical Management of Periodontal Disease in Children and Adolescents. Paul Baer, Shel don Benjamin Office and Practice Management Seminars. Charles Bress, Herman Cantor, Albert Salkind, Harold DeHaven, Ronald Fabrick, Jack Freiman, Michael S. Grossman, James McClenahan/Randy Vitek, Paul Rhodes Symposium on Hard Tissue Formation and Resorption in Periodontal Disease. Alfred Weinstock, Max Goodson, Lawrence Raisz Stress in Dental Practice; Why Dentists Com mit Suicide; Coping with Stress and Hyperten sion; The Relaxation Response. Richard Sword, Herbert Benson Sequential Management of Provisional Resto ration in Periodontal Prosthesis (a) as an Ad junct to Periodontal Therapy and (b) as Appli cable to the Permanent Restoration. Arnold Weisgold, Howard Skurow
SATURDAY, OCTOBER 8
(9) 8:30-1:00
(1)
(2) (3)
(4) (5) (6) (7) (8)
CONTINUING EDUCATION
COURSES
Chairman: Morris P. Ruben American Heart Association Course in Basic Life Support; Cardiopulmonary Resuscitation. Emerson Thomas (This course only, 8:00 a . m . to 2 : 0 0 p . m . ) Occlusal Adjustment of Natural Dentition. Hyman Smukler, Abraham Haddad, Waldyr Janson Allografts in Periodontal Reconstructive Sur gery—Skin, Sclera, and Bone. Raymond Yukna, Jules Klingsberg, Mick Dragoo, Robert Koch Limitations of Osseous Reconstructive Tech niques in Periodontics. Robert Schallhorn, Stuart Froum, Marvin Rosenberg Periodontal Problems and Considerations in Orthodontic Treatment. Roger Wise, Gary Reiser Biologic Rationale and Surgical Methods of Soft Tissue Reconstruction. Anthony Melcher, William Ammons Importance of Nutrition in Patient Care. Louis Fillios, Frederic Stare, Sanford Miller, William Steffee Medical Aspects of Periodontal Care. Law
(10) (11)
(12) (13)
(14)
9:00-l 2:00
RESEARCH FORUM
Chairman: Herbert Oshrain
IMPORTANT NOTICE T O MEMBERS
Chapter I, Section 5 of the Bylaws of the American Academy of Periodontology states: "Active and Associate members shall be required to attend at least one scientific session during each three-year period. "Attendance shall not be required of other classes of members. "In the event of illness or other extenuating circumstances, Active and Associate members may petition the Executive Council by letter through the Secretary for waiver of attendance requirements. Such an appeal shall be addressed to the Secretary not later than 60 days after the scientific session at which attendance may otherwise have been required."
Abstracts ORTHOPANTOMOGRAPHIC ASSESSMENT OF THE WIDTH OF ATTACHED GINGIVA
Talari, A . , and Ainamo, J. J Periodont Res 11: 177, July, 1976. Using a short piece of metal wire, attached to the tooth and gingiva by a strip of Squibb's Orahesive Dental Bandage, the muco gingival junction can be visualized on an orthopantomographic film. Thus, a method was developed for assessment of the width of at tached gingiva. Measurements, to the nearest millimeter, were made for each tooth from the mucogingival to the cementoenamel junction of 10 randomly selected adults. Follow-up examinations at 1 week and 2 month intervals were made to determine the reproducibility of the procedures in five adults. The total deviation caused by repeating the procedure was 0.7 mm, which was less than the one millimeter unit of measurement. Institute of Dentistry, University of Helsinki, F a b i a n i n k a t u 2 4 , S F - 0 0 1 0 0 Helsinki 1 0 , Finland. Dr. Alan W . Metzger DEVELOPMENT OF PLAQUE ON ENAMEL
Tinanoff, N., Gross, A . , and Brady J. M . J Periodont Res 11: 197, 1976. Plaque formation was studied using a technique whereby cylinders of surface enamel were placed in a maxillary Hawley appliance which was worn up to 7 days. Results from 75 cylinders kept in the mouth from 15 minutes to 7 days showed that a thin organic film covered the surface of the enamel after 1 hour. Microscopic studies of 2-day-old plaque revealed desquamated epithelial cells and bacteria adsorbed
to the enamel. Transmission electron microscopy showed different bacteria adjacent to the enamel than those adsorbed to the enamel surface. An extracellular material appeared to be excreted from the adsorbed altered bacteria. Desquamated epithelial cells were less abundant in mature plaque than in 1 and 2 day plaque samples. Microbiologic findings showed that the initial bacterial layer con sisted of cocci, and the flora changed to rods and filaments in the 7 day samples. U. S. Army Institute of D e n t a l Research, Walter Reed Army Medical Center, Washington, D.C. 20012. Dr. Alan W. Metzger
SALIVARY I G G AND I G A BEFORE AND AFTER PERIODONTAL THERAPY. A PRELIMINARY REPORT
Basu, M. K., Glenwright, H . D., Fox, E . C , and Becker, J. F. / Periodont Res 11: 226, July, 1976. Samples of the whole saliva of 12 patients, ages 20 to 43 with periodontal disease, were analyzed for immunoglobulins G and A . Local production of immunoglobulins during the development of periodontal disease previously had been shown to be characterized by a predominating synthesis of IgG. In the 12 patients of the current study IgG concentration was higher, and the IgA concentration lower than in clinically normal individuals. Six months after oral hygiene therapy and periodontal surgery, saliva samples were analyzed again and the concentration of the immunoglobulins was comparable with those of clinically normal mouths. Department of O r a l Pathology, The D e n t a l School, St. Chad's Queensway, B i r m i n g h a m B 6 4 6NN England. Dr. Rory O'Neill
