Paul M. Lambert

Positive Effect of Surgical Experience With Implants on Second-Stage Implant Survival

This Dental Implant Clinical Research Group study defined a learning curve for dental implant placement. Implants placed by inexperienced surgeons (< 50 implants) failed twice as often as those placed by experienced surgeons (> or = 50 implants). Implants placed during the first 6, 8, 10, 12, and 16 cases were compared with all others. The greatest difference was seen between the first nine cases and all others (P = .001), with later cases failing significantly less often. Inexperienced surgeons had more failures in the first nine cases (5.9%) than more experienced surgeons (2.4%). Surgeons with little or no previous experience must expect a definite learning curve. Previous experience may transfer and result in a shallower learning curve for subsequent systems.

The influence of 0.12% chlorhexidine digluconate rinses on the incidence of infectious complications and implant success.

The effect of perioperative chlorhexidine on the frequency of infectious complications through stage II was examined. Chlorhexidine was used perioperatively in 54.6% of patients (52.5% of implants) in a Dental Implant Clinical Research Group study with a database of 2,641 implants (595 patients). With chlorhexidine, there was a significant reduction in the number of infectious complications (4.1% vs 8.7%). Two percent of implants failed in the absence of an infectious complication, whereas 12% with infectious complications failed. This sixfold difference is highly significant. Chlorhexidine may reduce microbial complications when used in the immediate perioperative period.

Management of Dental Extractions in Irradiated Jaws: A Protocol With Hyperbaric Oxygen Therapy

Dental management of patients who are about to receive, or who have completed a course of therapeutic radiation involving the jaws, remains a perplexing problem. The center of debate is whether to extract teeth before radiation therapy or to manage them more conservatively and preserve the dentition to the greatest extent possible. The principal concern in this debate is how to minimize the risk of developing the mosl destructive complication associated with head and neck radiation, osteoradionecrosis (ORN). Tumoricidal levels of irradiation damage all tissues exposed. The accepted cause of ORN is progressive obliterative endarteritis and fibrosis resulting in hypovascular, hypocellular, and hypoxic tissues that can necrose spontaneously or in response to trauma. The incidence of ORN after radiation is reported to be widely different in several studies, ranging between 2% and 85Y0.‘~~ The causal relationship between dental extractions and ORN has been discussed by several authors.‘-“ Beumer et al” reported that the most common factors associated with ORN were postradiation extractions (26.5%), spontaneous bone exposure associated directly with the dentition secondary to dental disease (22.8%), and preradiation extractions (20.4%). In

AICRG, Part III: The Influence of Antibiotic Use on the Survival of a New Implant Design

PURPOSE The American College of Surgeons guidelines suggest that complex oral surgery may benefit from prophylactic antibiotic coverage. The use of preoperative antibiotics, postoperative antibiotics, or both during implant placement is a widely accepted practice in the United States, whereas dentists in other countries rarely use antibiotics. PURPOSE The purpose of this study was to determine if antibiotic coverage at the time of implant placement improves the survival of the Ankylos implant. METHODS As part of a comprehensive, multicentered, multidisciplinary, prospective, independent, international clinical study, designed and coordinated in the United States by the Ankylos Implant Clinical Research Group (AICRG), the use of preoperative (several regimens) and postoperative antibiotics (yes/no) were carefully documented to assess their influence on improving survival. A total of 1500 Ankylos implants were placed and followed for a period of 3 to 5 years. The decision to use antibiotics and the regimen to be employed was made by the treating surgeon. Failure was defined as removal of the implant for any reason. All data were entered into a computerized database for analysis. RESULTS The use of preoperative antibiotics produced no significant improvement (P = .21, Fishers exact test) in survival compared with those placed without antibiotic coverage. There was no significant difference between the regimens defined as AHA-1990, AHA-1997, and Petersons recommendations. CONCLUSIONS The results of this study suggest that there was little or no advantage to providing antibiotic coverage when placing this implant. These findings also suggest that the use of antibiotics for implant placement may not be as beneficial as once believed. If validated by other studies, the elimination of this practice for routine implant placement would represent a small but significant step forward in the reduction of unnecessary antibiotic use.

Detection of Radiation-Induced, Accelerated Atherosclerosis in Patients with Osteoradionecrosis by Panoramic Radiography

PURPOSE Osteoradionecrosis (ORN) of the mandible has long been considered the most destructive complication of head and neck irradiation. Recently, therapeutic irradiation has been implicated as the cause of induced/accelerated atherosclerosis of the cervical carotid artery and subsequent stroke. Panoramic radiography, previously shown to be capable of identifying carotid artery atherosclerosis in nonirradiated individuals, was used to assess the carotid vasculature of patients being treated for ORN. PATIENTS AND METHODS The panoramic radiographs of 61 men (mean age, 60.5 years; range, 41 to 77 years) who received therapeutic irradiation to the neck 36 months or more previously were assessed for the presence of carotid artery atherosclerotic lesions. Sixty-one control subjects who never received therapeutic irradiation, but who were similarly susceptible to atherosclerosis by virtue of age, were assessed in a like manner. RESULTS The irradiated individuals sustained a dose of 40 to 72 Gy to the area of the carotid bifurcation. Seventeen individuals (27.9%) with an irradiation dosage to the carotid bifurcation that averaged 59.2 Gy had a panoramic radiograph with a carotid atheroma (11 with unilateral lesions and six with bilateral lesions). The radiographs of the control subjects showed that three individuals (4.9%) had calcified carotid lesions. The mean age of these subjects was 66.1 years; two had unilateral lesions, and one had bilateral lesions. The difference in the proportion of individuals with ORN who manifested carotid artery atherosclerosis on their panoramic radiographs was statistically significant (P = .001) when compared with the nonirradiated control subjects. The lesions seen in both populations had a similar morphologic appearance and were radiographically located within the soft tissues of the neck 1.5 to 4.0 cm inferior-posterior to the angle of the mandible. CONCLUSIONS Individuals with radiation doses sufficient to cause osteoradionecrosis of the mandible are at significantly higher risk of developing carotid artery atherosclerotic lesions than age-matched, nonirradiated controls.

A two-piece surgical splint to facilitate hydroxylapatite augmentation of the mandibular alveolar ridge

Details of the design and fabrication of a two-piece splint that facilitates the HA augmentation of the mandibular alveolar ridge are presented. The use of the splint has eliminated migration of HA particles, reduced elevation of the vestibule, and increased the predictability of the outcome of the procedure.

AICRG, Part IV: Patient Satisfaction Reported for Ankylos Implant Prostheses

PROBLEM Although many maxillary dentures exhibit sufficient retention and stability for patients to adapt well to them, mandibular dentures present a major challenge. The introduction of the endosseous dental implant provided the opportunity for the patient to have esthetic replacements (implant prostheses) that were retentive and stable for all missing natural teeth. METHOD This paper reports on the satisfaction of over 470 patients with implant prostheses fabricated using a new and innovative implant design (Ankylos, Dentsply-Friadent, Mannheim, Germany). RESULTS A total of 1500 Ankylos implants were placed, restored, and followed for 3 to 5 years. Patients were asked to respond to a series of questions related to their satisfaction with their new replacements for missing natural teeth. A total of 95.6% of the patients rated chewing ability with Ankylos prosthesis as excellent to good; 92.2% indicated a significant improvement in their ability to chew; 92.6% reported overall clinical function much better than conventional dentures; 99.1% indicated that speech had improved or was not changed; 96.3% indicated hot and cold foods tasted better; 98.8% indicated no pain or discomfort during clinical function; 99.4% liked their new implant prosthesis; 98.0% would seek implant-prostheses treatment again, if necessary; 99.1% would recommend implant prostheses to friends and relatives; and 98.8% indicated the advantages of Ankylos prostheses far exceeded any disadvantages that may exist. CONCLUSIONS Patients indicated that they (1) were highly satisfied with the final results of the replacements for their natural teeth that were retained or supported by this new implant design, (2) would not hesitate to recommend this form of treatment to their friends and relatives, and (3) would not hesitate to seek the same treatment again if necessary in the future.

Autogenous dermal graft coverage of submerged roots in the dog

Dermal grafts were compared with conventional supraperiosteal recipient beds grafted with split-thickness skin for covering submerged vital roots in six dogs. Several potential advantages of this new technique are suggested.

Oral and Maxillofacial Surgery Careers in the Military and Department of Veterans Affairs

Within the Federal Services, a myriad of career opportunities exist for the oral and maxillofacial surgeon. The Department of Veterans Affairs and the Department of Defense, consisting of the Army, Navy, and Air Force, have the greatest number of positions available. Federal Services careers are also for those oral and maxillofacial surgeons with a calling to serve their country. The personal fulfillment, patient appreciation, and inter- and cross-specialty relationships are unique to this practice setting because it is free of many of the impediments, to these relationships, that exist in private practice. The highlights of a career in each of these Federal Services are described in this article.