Journal of Periodontal Research 16: 130-133, 1981 Short Communication New attachment after surgical treatment and acid conditioning of roots in naturally occurring periodontal disease in dogs G. BOGLE. D. ADAMS, M. CRIGGER, B. KJLINGE AND J. EGELBERG School of Dentistry, Loma Linda University. Loma Linda. California. USA (Accepted for publication June 25, 1980} Several pathologic changes occur in the pe- riodontally diseased root surface which may significantly affect the outcome of thera- peutic regenerative attempts (see review by Garrett 1977). It is also conceivable that long-standing periodontal disease may in- duce local or systemic changes which may affect the repair potential at the site of treatment. In our laboratories we have con- ducted a series of therapeutic studies uti- lizing experimentally induced through-and- through furcation pockets (Johansson. Nil- veus & Egelberg 1978, Nilveus. Johansson & Egelberg 1978, Crigger et al. 1978, Nil- veus et al. 1980, Nilveus & Egelberg 1980. Selvig et al. 1980. Klinge, Nilveus & Egel- herg 1980). It is not known if these experi- mentally induced "chronic" periodontal le- sions will produce simiiar changes of the periodontaily involved tissues as naturally occurring periodontal disease. Thus, the question remains whether experimental le- sions constitute a valid substitute for nat- ural disease to study the effect of thera- peutic procedures. Our previous studies using experimental- ly induced furcation defects have shown that surgical debridement combined with citric acid conditioning of the instrumented root surface results in new attachment and closure of these defects. The present study was performed to find out if the same ther- apy would result in new attachment in dogs with naturally developed furcation defects as well. Eight female. 9 to 12 year old beagles were used. (The dogs were obtained from a colony of beagles at Laboratory Research Enterprises. Inc.. Kalamazoo, Michigan, USA). Tbe periodontal disease in these dogs had resulted in loss of some teeth, severe peHodontal destruction, and tooth hyper- mobility. A total of 29 mandibuiar premolars showed clinical through-and-through fur- cation defects. In 13 mandibuiar premo- lars the disease process had not resulted in patent furcation pockets. Through-and- through furcation defects were experimen- tally created in these unaffected teeth using the method of Johansson et al. (1978). The induced defects provided a means of com- parison to the naturally occurring defects in the aged beagle dog. Reconstructive periodontal surgery and postoperative care were carried out as de-