Use of immediately loaded press-fit cylinder implants in oral reconstruction.

Press-fit implants can be used to meet the prosthetic needs of patients who require immediate loading of their implants. This procedure may be necessary because of a patient's unwillingness and/or inability to tolerate a removable prosthesis. The implants reported in this study had a similar success rate to those immediately loaded screw-type implants previously reported by others. The lack of large numbers of long-term immediately loaded implants dictates the need for detailed informed consent when using immediately loaded cylinder implants for dental reconstruction.

Team approach for closure of oroantral and oronasal fistulae.

Oroantral and oronasal fistulas present with a broad range of causation, size, duration, and extent of infection involving the nose and paranasal sinuses. Accurate diagnosis of the extent of the disease with appropriate radiographic evaluation will guide the surgeon to select an approach that addresses all of the infected sites. When significant sinus disease is found, an endoscopic approach to restoring drainage in all of the involved sinuses can promote predictably successful closure of oroantral and oronasal fistulas. The multispecialty team approach to this disease, with the concomitant management of the sinusitis and fistula closure, is a significant advance in the successful management of this chronic condition.

The incidence of altered sensation of the mental nerve after mandibular implant placement.

PURPOSE: This study was designed to determine the incidence of altered sensation in patients undergoing mandibular endosseous implant placement. PATIENTS AND METHODS: Ninety-four consecutive patients who underwent the placement of mandibular implants constituted the study group. The only patients that were excluded from this study were those who had preexisting injury to the trigeminal nerve. Patients were followed using standard neurologic testing during the period immediately following implant placement through 6 months. Four hundred five implants were placed in 43 female and 51 male patients. Implant length selection was based on panoramic radiographs using known markers to correct for distortion. In 13 of the patients, the mandibular canal was not adequately visualized, and a computed tomography (CT) scan was used to plan the implant locations. Implants were selected to be located 2 mm above the inferior alveolar canal based on the panoramic images and 1 mm above the canal based on CT images. RESULTS: Eight patients reported altered nerve sensation at their first postimplant visit (8.5%). None of the patients experienced hyperesthesia or dysesthesia. Four of the eight patients with altered sensation had no objective findings or decreased nerve function. One of the patients remained totally anesthetic for 2 months, but reported return to normal function at 4 months. CONCLUSIONS: These findings indicate that a small percentage of patients experience altered sensation after the placement of mandibular endosseous implants. Unlike previous studies, no permanent altered sensation was found. By using proper treatment planning, one can offer endosseous implants with minimal risk of injury to the trigeminal nerve.

Location of incisive canal in relation to central incisor implants.

Computerized tomography (CT) scanning, now widely used for the diagnosis and treatment planning of dental implant sites, can be more specifically useful with integrated computer software. In this instance, the potentially critical incisive foramen area at the premaxilla is analyzed to better under stand its configuration and volume relative to the placement of root-form implants.

Interactive CT diagnostics, planning and preparation for dental implants.

The insertion of dental implants is multifaceted. Adequate containment of the implant body requires not only a measurable volume of bone but also an acceptable density of this osseous foundation. Through interactive computerized axial tomography (CAT), not only are such measurements conveyed to the clinician, but vital structures that should be avoided or at least accounted for are portrayed in a three-dimensional manner. Predict-ability is enhanced, and the implants can be directed for prosthetic use in conjunction with surgical guides (templates).

Effect of supplemental gases on end-tidal CO2 and oxygen saturation in patients undergoing fentanyl and midazolam outpatient sedation.

Forty-six American Society of Anesthesiologists Class I and II adults were randomly assigned to one to two study groups. Each subject received 0.7 microgram/kg of fentanyl and a titrated dose of midazolam. One group received 100% supplemental oxygen (O2) while another group received 50% nitrous oxide (N2O) and 50% O2. End-tidal carbon dioxide (EtCO2) and O2 saturation (SpO2) were measured at 5-min intervals throughout the procedure. We conclude that there was no significant difference in EtCO2 or O2 saturation between the two groups.

Comparison of recovery of propofol and methohexital sedation using an infusion pump.

Two sedative anesthetic agents administered by an infusion pump were compared during third molar surgery. Forty American Society of Anesthesiologists (ASA) class I or II volunteers were randomly allocated to two groups. All subjects received supplemental oxygen via a nasal hood, fentanyl (0.0007 mg/kg intravenous [i.v.] bolus), and midazolam (1 mg/2 min) titrated to effect. Patients then received either 0.3 mg/kg of methohexital or 0.5 mg/kg of propofol via an infusion pump. Upon completion of the bolus, a continuous infusion of 0.05 mg/kg/min methohexital or 0.066 mg/kg/min propofol was administered throughout the procedure. Hemo-dynamic and respiratory parameters and psychomotor performance were compared for the two groups and no significant differences were found. The continuous infusion method maintained a steady level of sedation. Patients receiving propofol had a smoother sedation as judged by the surgeon and anesthetist.

Bone formation and implant degradation of coralline porous ceramics placed in bone and ectopic sites.

PURPOSE: This study was undertaken to determine the resorption rate of porous ceramic implants. The hypothesis was that implants placed in soft tissues would degrade more rapidly than implants placed in bone. MATERIALS AND METHODS: To test this hypothesis, implants were manufactured by applying a thin coating of hydroxylapatite onto an interconnected, porous calcium carbonate substrate. Control implants were made entirely of hydroxylapatite with identical microstructure. Two adult dogs received a total of 56 implants placed in the femur, skeletal muscle, and subcutaneous tissues. After killing the animals at 4 months, the specimens were removed, embedded in plastic, sectioned, and either stained for light microscopic examination or subjected to quantitative image analysis using a scanning electron microscope. RESULTS: Contrary to the hypothesis, the rate of degradation was faster for implants placed in bone than in soft tissue. Within the 4 months, degradation was 24% to 63% in bone, depending on the composition. However, it was not statistically significant in either intramuscular or subcutaneous tissue. A surprising observation was that bone ingrowth occurred in 67% of the implants placed in soft tissues. On average, it was 4.3% in intramuscular sites and 6.6% in subcutaneous sites. This bone was histologically normal in 71% of the implants containing bone. CONCLUSION: This study demonstrates that porous ceramic implants composed of hydroxylapatite on calcium carbonate will degrade more rapidly in bone defects than in soft tissue sites. In addition, implants with interconnected porosity and surfaces of hydroxylapatite will become ingrown with bone even after placement in soft tissues. The exact mechanisms for both of these phenomena are not understood.

Comparison of propofol and methohexital for deep sedation.

The purpose of this investigation was to compare two sedation techniques for use in outpatient third molar surgery. Forty ASA class I or II volunteers were randomly allocated to two groups. All subjects received supplemental oxygen via a nasal hood, sublimaze (.0007 mg/kg [corrected] intravenous bolus), and midazolam (.5 mg/min) titrated to effect. Using an incremental bolus technique, group A then received methohexital, while group B received propofol. Both groups maintained stable mean arterial pressure, oxygen saturation, and end-tidal CO2 throughout the perioperative period. However, group A had a dramatic increase in heart rate (26.7% versus 13.9% for group B [P < .05]). Better postoperative psychomotor performance (P < .05) as measured by the Trieger Dot analysis was demonstrated by patients who received propofol. It was concluded that propofol is superior to methohexital for intravenous sedation.

Endosteal implants following tumor surgery and avulsive trauma.

Endosteal implants are part of the reconstructive armamentarium used by head and neck surgical teams in cases of trauma or tumor ablation when inadequate residual anatomy prevents the fabrication of a traditional prosthesis. Three cases of implant supported prosthesis have been presented. Use of endosteal implants is an additional step toward functional reconstruction.

A comparison of dentoalveolar and venous blood.

Dentoalveolar blood from extraction sites immediately after surgery and venous blood from 28 adult patients was compared for quantitative, qualitative, chemical, and cellular differences. The absence of stem cells, osteoblasts, and osteoclasts from dentoalveolar blood suggests a very low osteogenic potential, no more than that of venous blood. This finding contradicts information supplied by the manufacturer of a microporous, polymeric, composite graft material recommended for use with placement of implants in immediate extraction sites and as onlay grafts to treat ailing implants. The manufacturer's directions call for mixing the alloplast with bleeding marrow harvested from holes drilled in the mandibular symphysis or from a curetted dental socket immediately after a dental extraction in order to stimulate immature marrow cells to form osteoblasts.