Biomedical subjects

N U Zitzmann

Publications and source records attributed to N U Zitzmann.

25 records · Page 2Linked to original sources

PubMed1999

Anterior single-tooth replacement: clinical examination and treatment planning.

The replacement of a single anterior tooth is a complex, challenging procedure that can be accomplished with implant-supported restorations as well as conventional porcelain-fused-to-metal and resin-bonded fixed partial dentures. A comprehensive diagnostic form may be beneficial in determining the most effective means of rendering treatment for each patient. This article demonstrates the use of this form, diagnostic models, and radiographs to diagnose and restore three patients who presented for the replacement of a single tooth in the anterior maxilla.

Adult↗

PubMed1998

Sinus elevation procedures in the resorbed posterior maxilla. Comparison of the crestal and lateral approaches.

OBJECTIVES: The purpose of this study was to compare three different methods for sinus elevation: (1) the lateral antrostomy as a two-step procedure, (2) the lateral antrostomy as a one-step procedure, and (3) the osteotome technique with a crestal approach. Indication criteria were defined, based on the residual bone height measured from computed tomography scans, for the sake of applying the appropriate technique. STUDY: In 30 patients designated for implant treatment in the resorbed posterior maxilla, 79 implants were placed in combination with a bone-grafting material for sinus augmentation. The final bone heights were measured from panoramic radiographs or post-operative computed tomography scans. RESULTS: The success rate for the osteotome technique was 95% during the 30-month study period; no failures occurred in any site treated with a lateral antrostomy. The gain in bone height was comparable for the one-step (median = 10 mm) and two-step (median = 12.7 mm) lateral antrostomies. These sites exhibited a significantly greater increase in bone height (p < 0.001) than did the sites in which the osteotome technique was applied (mean = 3.5 mm). The histologic sections showed both bone apposition in intimate contact with the bone-grafting material particles and initial signs of its remodeling. CONCLUSIONS: The results indicate that the osteotome technique can be recommended when more than 6 mm of residual bone height is present and an increase of about 3 to 4 mm is expected. In cases of more advanced resorption a one-step or two-step lateral antrostomy has to be performed.

Adult↗

PubMedDate not supplied

Clinical and technical aspects of implant-supported restorations in the edentulous maxilla: the fixed partial denture design.

PURPOSE: The aim of the present article was to describe the treatment planning for an implant-supported maxillary fixed prosthesis and the clinical procedure involved, including the laboratory fabrication sequence. MATERIALS AND METHODS: If patients request a fixed prosthesis to restore the edentulous maxilla, it is essential to decide as soon as possible whether this prosthesis design can satisfy the requirements of esthetics, phonetics, comfort, and function. Thus, the crucial clinical factors need to be checked during examination. Furthermore, the relationships between ideal implant angulation, available bone, and intended crown should be assessed using reformatted computed tomography. RESULTS: In patients with minimal bone resorption and limited intermaxillary space, implants can usually be placed in the prosthetically driven implant position for a fixed prosthesis. To evaluate and optimize esthetics, biology, and function, a fixed provisional restoration should be inserted for a 6-month diagnostic period. The ideal provisional then serves as a guide for the final restoration. CONCLUSION: If clinical and radiologic diagnostics indicate that an implant-supported fixed complete denture is feasible, meticulous presurgical planning, precise execution of implant positioning, and a progressive prosthetic treatment sequence are required. The ceramometal fixed implant-supported restoration can then be established in an ideally prepared and matured oral environment.

Dental Prosthesis, Implant-Supported↗

PubMedDate not supplied

Implant-supported removable overdentures in the edentulous maxilla: clinical and technical aspects.

PURPOSE: The aim of this article is to describe the indication criteria and the treatment planning for a maxillary implant-supported removable overdenture. Prostheses are designed according to the requirements of the bar system and the factors influencing the extension of the prosthesis base. MATERIALS AND METHODS: The decisive factors in determining whether a bar-retained overdenture prosthesis is indicated should be evaluated during the initial clinical examination and with the help of a reformatted computed tomographic (CT) scan that is performed with a radiologic template in place. Titanium markers represent the ideal location of the denture teeth in the diagnostic setup so that the implant position can be selected and the available space for the bar system can be assessed vertically and horizontally. RESULTS: For the overdenture prosthesis that is solely implant supported 6 to 8 implants are placed ideally at a distance of about 10 to 14 mm from center to center. A prefabricated bar system that allows the clips to be inserted between the implants can then be used. When the available bone restricts implant placement to adjacent tooth positions an individually milled bar that includes additional frictional pins and/or retentive elements needs to be planned. The prosthesis design, in particular its buccal and palatal flange extension, is determined during setup try-in, taking into account the patient's smile line, their need for facial support, and their phonetic requirements. CONCLUSION: The removable implant-supported overdenture offers flexibility in placing implants in either adjacent tooth positions or with greater distances between them depending on the available bone, as either conventional bar and clip systems or individually milled bars can be used. Adjustment of the buccal prosthesis flange and the palatal prosthesis base is made to fulfill the patient's requirements concerning esthetics, phonetics, comfort, and function.

Dental Implantation, Endosseous↗

PubMedDate not supplied

Bone and soft tissue integration to titanium implants with different surface topography: an experimental study in the dog.

The aim of the present experiment was to study the peri-implant soft and hard tissues formed at titanium implants with 2 different surface configurations and to give a topographic description of the surfaces examined. In 5 beagle dogs, the mandibular premolars were extracted. Three months later, 4 self-tapping standard implants (SI) and 4 Osseotite implants (OI) of the 3i Implant System were placed. The marginal 3 mm of the OI is turned, while the remaining part has an acid-etched surface structure. Abutments were connected after 3 months. A plaque control period was initiated, and after 6 months block biopsies were obtained. From each animal 2 units of each implant type were processed and embedded in EPON. The remaining biopsies were processed for ground sectioning. The histometric measurements performed on the EPON sections revealed that the peri-implant soft tissues and the marginal level of bone-to-implant contact were similar for SI and OI sites. In the ground sections, bone-to-implant contact (BIC%) and bone density assessments were made in 2 different zones. Zone I represented the contact area measured from the marginal level of bone-to-implant contact (B) to a position 4 mm above the apex of the implant, and zone II represented the apical 4 mm of the implant. For the SI sites, the BIC% was 56.1% in zone II and 58.1% in zones I + II. The corresponding figures for the 01 sites were 76.7% and 72.0%. The BIC% was significantly larger at OI than at SI sites. Bone density values were similar at the SI and OI sites.

Acid Etching, Dental↗

PubMedDate not supplied

Long-term results of implants treated with guided bone regeneration: a 5-year prospective study.

The aim of this prospective 5-year longitudinal study was to follow endosteal implants in which guided bone regeneration (GBR) was applied during implant placement. In 75 patients, defects around implants (Branemark System) were treated with Bio-Oss and Bio-Gide (112 implants). In split-mouth patients in this group, Bio-Oss and Gore-Tex were used in the second defect site (41 implants). All 75 patients had at least 1 implant that was entirely surrounded by bone and served as the control (112 implants). After placement of the definitive prostheses (single-tooth, fixed, or removable implant prostheses), patients were recalled after 6 months and then every 12 months during a 5-year observation period. The following variables were investigated: implant survival, marginal bone level (MBL), presence of plaque, peri-implant mucosal conditions, height of keratinized mucosa (KM), and marginal soft tissue level (MSTL). The cumulative implant survival rate after 5 years varied between 93% and 97% for implants treated with or without GBR. The mean MBL after 60 months was 1.83 mm for sites treated with Bio-Oss and Bio-Gide, 2.21 mm for sites treated with Bio-Oss and Gore-Tex, and 1.73 mm for the control sites. The MBL values were found to increase significantly with time and differed significantly among the treatment groups. During the observation period, KM varied between 3.16 and 3.02 mm. A slight recession of 0.1 mm was observed, and plaque was found in 15% of all sites and was associated with inflammatory symptoms of the peri-implant mucosa. It was observed that such symptoms and recession correlated more strongly with the type of restoration than with the type of treatment. This study demonstrated that implants placed with or without GBR techniques had similar survival rates after 5 years, but that bone resorption was more pronounced in sites with GBR treatment. It was assumed that the use of GBR is indeed indicated when the initial defect size is larger than 2 mm in the vertical dimension.

Adult↗

PubMedDate not supplied

Resorbable versus nonresorbable membranes in combination with Bio-Oss for guided bone regeneration.

The purpose of this clinical investigation was to compare the new resorbable collagen membrane, Bio-Gide, to the conventional expanded polytetrafluoroethylene material (Gore-Tex) for guided bone regeneration in situations involving exposed implant surfaces. Over a 2-year period, 25 split-mouth patients were treated randomly: one defect site was treated with Bio-Gide and the other defect site with Gore-Tex; all 84 defects were filled with Bio-Oss and covered with the respective membrane. The defect types, their dimensions, and their morphology were measured in detail initially and at re-entry to allow for calculation of the exposed implant surface. Changes in defect surface for both types of membranes were statistically significant (P < .0001); however, no statistical significance (P > .94) could be detected between the two membranes. The mean average percentage of bone fill was 92% for Bio-Gide and 78% for Gore-Tex sites. In the latter group, 44% wound dehiscences and/or premature membrane removal occurred. The resorbable membrane, Bio-Gide, in combination with a bone graft, can be a useful alternative to the well-established expanded polytetrafluoroethylene membranes.

Absorption↗