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Biomedical subjects

R J Lazzara

Publications and source records attributed to R J Lazzara.

12 recordsLinked to original sources
PubMed1999

A human histologic analysis of osseotite and machined surfaces using implants with 2 opposing surfaces.

A human histologic study was conducted to compare the percentage of bone-to-implant contact (BIC) at 6 months for Osseotite and machined, commercially pure titanium implant surfaces. To eliminate potential influences caused by differences in bone density at different intraoral locations, 2 mm x 5 mm, threaded, 2-surfaced titanium implants were manufactured; 1 side received the Osseotite surface modification and the opposite side maintained a machined surface. In each of 11 patients, 1 test implant was placed in the posterior maxilla (Types III and IV bone) during conventional dental implant surgery. Following 6 months of unloaded healing, the conventional implants were uncovered, and the test implants and surrounding hard tissue were removed. Histologic analysis indicated that at 6 months of unloaded healing, the mean BIC value for the Osseotite surfaces (72.96% +/- 25.13%) was statistically significantly higher (P < 0.05) than the mean BIC value for the machined surfaces (33.98% +/- 31.04%). When the BIC values for the machined and Osseotite surface pairs were ranked from high to low based on the machined BIC value range of 93% to 0%, the upper 50th percentile (20 surface pairs) mean BIC value was 86.1% +/- 16.7% for the Osseotite surfaces and 60.1% +/- 18.3% for the machined surfaces. The lower 50th percentile (19 surface pairs) mean BIC value was 59.1% +/- 25.3% for the Osseotite surfaces and 6.5% +/- 10.8% for the machined surfaces. Differences between mean BIC values for the 2 surfaces in both the upper and lower 50th percentiles were statistically significant (P < 0.05). The results of this study indicate that in the poorer quality bone typically found in the posterior maxilla, a statistically significantly higher percentage of bone contacts Osseotite surfaces when compared to opposing machined surfaces on the same implant.

Alveolar Process↗
PubMed1998

A prospective multicenter study evaluating loading of osseotite implants two months after placement: one-year results.

Historically, the recommended time between placement and functional loading of machined-surface dental implants has been 3 months for the mandible and 6 months for the maxilla. However, such recommendations are a result of evaluating randomly chosen healing times during the initial phase of implant development and are based on the subsequent clinical outcome of either implant integration or mobility. In recent years, histologic and experimental studies have shown that specifically designed micro-topographic implant surfaces can result in increased bone-to-implant contact at earlier healing times than obtained with machined-surface implants. Histologic and clinical studies investigating early and immediate implant loading support the premise that implants can be placed into function earlier than previously recommended. With the development of specifically designed implant surfaces and the utilization of time-saving surgical (one-stage surgical protocol) and prosthetic (implant position indexing) techniques, patients are now being restored and returning to function sooner than previously thought possible. The purpose of this multicenter clinical investigation is to evaluate the efficacy of loading Osseotite dental implants (3i-Implant Innovations Inc., Palm Beach Gardens, Florida) at 2 months and to determine the effect of early loading on implant performance and survival. A total of 429 Osseotite implants were placed in 155 patients (87 females and 68 males; mean age 54.0 +/- 13.7 yr), at 10 study centers, and subsequently loaded 2.1 +/- 0.7 months following placement. A single-stage surgical protocol was followed, with implants indexed immediately or impressed 4 to 6 weeks following placement. Patient restorative treatments included placement of 83 single-implant provisional restorations and 129 splinted, two-, three-, and four-implant supported maxillary and mandibular provisional restorations. The mean time from prosthetic loading to the most recent follow-up evaluation was 10 +/- 1.3 months. Seven of the 429 implants did not integrate; of these, six were identified prior to loading and one was identified 1 month after loading. The cumulative implant survival rate was 98.5% at 12.6 months. The cumulative post-loading implant survival rate was 99.8% at 10.5 months. The preliminary results of this clinical investigation suggest that successful functional loading of the Osseotite dental implant is possible at 2 months following noncomplicated implant placement.

Adult↗
PubMed1996

The sinus elevation procedure in endosseous implant therapy.

Since the initial application of sinus lift augmentation and implant placement in the mid-1970s, there have been some variations in technique used and graft material applied. Although most authors continue to use the lateral wall, Caldwell-Luc approach, less invasive procedures such as the osteotome procedure for sinus elevation, graft, and implant placement have been proposed. Many authors use iliac crest bone that is of both a cancellous and cortical nature. However, due to the high morbidity rate of this procedure, other donor sources are explored in this review. Good success rates are shown with intraoral bone and combinations of intraoral bone with both resorbable and nonresorbable materials. Varying results are reported with demineralized freeze-dried bone, although its use in combination with hydroxyapatite seems to improve its effectiveness. All reports of clinical success are relatively short term (6 years to 6 months). Medication recommendations and posttreatment prosthetic care are covered.

Antibiotic Prophylaxis↗
PubMed1995

Transplantation of a preosseointegrated implant from the mental area to a maxillary sinus graft.

When maxillary sinus grafting is performed to allow placement of fixed restoration in edentulous posterior sites, standard procedures involve placement of the sinus graft and then, after a graft-maturing time, placement of implants, which must osseointegrate before they can be used to support a restoration. Transplantation of a preosseointegrated implant from the mental area to the graft site may be preferable to standard two-step procedures. Advantages of the transplant procedure include reduction in total treatment time, a more predictable therapeutic outcome, and, it appears, improved bone quality, configuration, and retention around the implant.

Bone Transplantation↗
PubMed1993

Hierarchy of objectives in implant placement to maximize esthetics: use of pre-angulated abutments.

Limitations in position, quality, or dimension of bone often require that implants be placed in a nonideal axial inclination. Use of preangulated abutments may be the method of choice when anatomic limitations preclude the axial placement of an implant. This paper discusses the indications for and advantages of the use of preangulated abutments to fulfill esthetic and functional objectives.

Dental Abutments↗
PubMed1989

Use of osseointegrated implants for replacement of single teeth.

This article uses clinical examples to show applications of single tooth replacements. With coordinated planning and efforts on the part of the surgeon and the restorative dentist, optimum results, both esthetically and functionally, can be achieved in treating these partially edentulous patients.

Adolescent↗
PubMedDate not supplied

Criteria for implant selection: surgical and prosthetic considerations.

With the availability of osseointegrated implants in an assortment of diameters as well as lengths, the implant selection process has become more complex. To expand treatment options and optimize outcome, implant selection should be guided by a number of surgical considerations and prosthetic requirements specific to each implant site. Small diameter implants are appropriate in areas of narrow ridge dimension or where prosthetic space is limited. Wide diameter implants are well suited to posterior regions with poorer bone quality and restricted vertical height. They provide a higher degree of implant-to-bone contact, increased stability, reduced screw stress, and an improved emergence profile. The learning objective of this article is to discuss these considerations and to outline the implant selection criteria.

Alveolar Bone Loss↗
PubMedDate not supplied

Managing the soft tissue margin: the key to implant aesthetics.

Developing a natural contour and anatomically dimensioned soft tissue margin is critical to attaining an aesthetic implant restoration. Anatomically dimensioned temporary healing abutments can be used to guide the soft tissue healing to the size of the tooth to be replaced. This article discusses aesthetics, indications, contour, available sizes of the abutment, crown "ledge," soft tissue maturation, healing time, and predictability of the procedure. The learning objective of this article is an enhanced understanding of the principles and placement technique of the temporary healing abutments.

Crowns↗