Prosthetic considerations in the fabrication of surgical stents for implant placement

The utilization of surgical stents/templates for implant placement is of significant importance to the success of the definitive prosthesis. However, major conceptual differences exist between surgical stents designed for implant-supported crowns and bridges and those designed for implant overdentures. In addition, various types of surgical stents exist within each group. In either case, optimizing the prosthetic result by customization of the stent should be a major consideration in the fabrication process. The design of the stent must account for several treatment conditions, including position of the implant, the tissue present, and the anticipated prosthesis. The teaching objective of this article is to present the prosthetic considerations in the fabrication and customization of surgical stents. The article compares the two groups and offers specific guidelines for the fabrication of surgical stents for the various types of restorations within each group.     

Implants in the partially edentulous patient: restorative considerations

Restorative considerations are critical to the long-term success of fixed implant-supported prostheses, especially in the posterior quadrants of the partially edentulous patient. The parafunctional habit of bruxism must be identified and addressed. The restoration should dictate implant placement. Control of forces directed upon the prosthesis and implants is critical to long-term success. Anatomic limitations to implant placement and surgical procedures to correct these deficiencies must be considered for their impact on the prosthetic restoration. Nonaxial forces or bending moments should be minimized by the use of an adequate number, position and alignment of implants; by control of the occlusion; and by design of the prosthesis. The patient must understand the risks, limitations, costs and time commitments of implant restorations prior to treatment.     

Lipid peroxidation in patients with ischemic heart disease, hyperlipidemia and/or hypertension while polyunsaturated omega-3 fatty acids of plant and animal origin were in their diet

Missing anterior teeth are being replaced by implant-supported restorations quite frequently in modern dentistry. Providing the patient with a temporary prosthesis prior to or following implant fixture placement must satisfy established esthetic and functional criteria. When orthodontic treatment is included as part of the overall treatment effort, additional considerations include the retention and stabilization of newly established tooth positions. This article describes the fabrication, use and advantages of a provisional anterior prosthesis that replaces missing teeth prior to or following implant placement.     

Implant placement without flaps: a single-stage surgical protocol--Part 1

Osseointegrated implants have been demonstrated to be predictable, efficacious means of restoring aesthetics and long-term function to edentulous patients. Although the surgical and placement protocols for the use of implant therapy have continued to evolve, specific criteria must be addressed when utilizing this modality. The objective of this article is to describe the requisites for proper implant placement and demonstrate the use of a novel surgical protocol to insert implant fixtures in selected edentulous sites with a mucosal tissue punch rather than a conventional flap elevation procedure.     

Rehabilitation of patients with severely resorbed maxillae by means of implants with or without bone grafts. A 1-year follow-up study

Forty-three patients with severely resorbed maxillae who had been referred for implant treatment were assigned to one of three treatment groups: bone grafting and implant placement (graft group); modified implant placement but no bone grafting (trial group); or optimized complete dentures (no-implant group). Sixteen, 20, and 7 patients, respectively, were assigned to the three groups. At the 1-year follow-up, 10% of the implants had been lost. Only a few of the failures (3/22) occurred after prosthesis placement. The cumulative success rates were 83% in the graft group and 96% in the trial group. A substantial reduction of the grafted bone, especially of the onlay grafts, occurred in many patients. During the period from prosthesis connection to the 1-year follow-up, marginal peri-implant bone loss was on average 0.5 mm. Despite the often demanding procedures involved, all but one patient in each implant group said that they would undergo the treatment again. Most patients were very satisfied with the treatment outcome and their improved masticatory ability. Those who had renounced implant treatment appeared modestly adapted to their optimized dentures, but reported retention problems and less satisfaction with mastication.     

The custom implant impression coping: technical note

Unsupported soft tissue can collapse around a submerged implant or abutment head during the time interval between removal of the provisional prosthesis and placement of the impression material. A technique is described for accurately recording the implant or abutment position as well as the position of the soft tissue for a single tooth restoration using the provisional prosthesis as a custom implant impression coping.     

Implant reconstruction of the jaws and craniofacial skeleton

Full oral rehabilitation with a high degree of success is now possible with osseointegrated implants. Osseointegration is a direct connection between living bone and the titanium implant at the level of the light microscope. Osseointegrated implants are currently used to replace single teeth, support fixed bridges and stabilize full dentures. These implants can also be placed extraorally for attachment of facial prosthesis. The surgical technique used to place implants intraorally into jaws or facial skeleton is performed in two stages using a local anesthetic and/or conscious sedation. During stage I surgery, holes are placed into the jaw using a series of gradually larger diameter burs until the desired diameter and depth of the bony preparation is achieved. The implant is then placed. The implant must remain undisturbed for 4 months for osseointegration to take place. Stage II surgery is then required to remove the mucosa over the implant and place the transmucosal abutment. After 1-2 weeks of healing, the restorative dentist can take an impression and fabricate the prosthesis. On occasion, it is necessary to augment the height and width of the atrophic jaw with autogenous or allogeneic bone grafts prior to implant placement. Bone grafts are sometimes placed on the floor of the nose or the floor of the maxillary sinus. Guided tissue regeneration is a technique used to generate bone within bony defects adjacent to implants. With long-term rates of success (5 years) of 99% for implants placed in the mandible and 95% for those placed in the maxilla, reconstruction of the jaws and cranial facial skeleton with osseointegrated implants has become the treatment of choice.     

Design, maintenance and biomechanical considerations in implant placement

Successful treatment using implants involves careful consideration of fixture placement and prosthesis design if the biomechanical conditions are to be optimized. These parameters may be related to the implant/tissue interface at the individual fixture level, and thence to the relationship between the components of a prosthesis. The influence of the nature and magnitude of occlusal forces can also be significant and should be carefully assessed before placement.     

Use of X-ray diffraction for studying the temperature dependence of the Young modulus of protein crystals

Conventionally, for dental reconstruction after bone grafting of the congenital residual alveolar cleft, a fixed prosthesis or removable partial denture is used. In this paper, residual alveolar cleft reconstruction with an osseointegrated implant following secondary bone grafting is described. The patient underwent secondary bone grafting of the residual alveolar cleft at the age of 18 years. One osseointegrated implant was placed in the bone bridge 8 months after bone grafting. No problems up to 1 year after the fabrication and placement of the fixed prosthesis have been observed.     

An evaluation of measures of synonymous codon usage bias

OBJECTIVE: The aim of this study was to determine whether bone quality, as assessed by osteometry and histologic parameters, can be used to predict implant integration in conjunction with maxillary sinus reconstruction. STUDY DESIGN: Twelve patients with severely atrophied maxillary alveolar processes were treated through use of a two-stage surgical reconstructive strategy with implant placement 4 months after bone grafting. Bone biopsy specimens taken from the iliac crest peroperatively and from the sinus inlay sites 1, 2, 4, 6, or 12 months postoperatively were analyzed by light microscopy and osteomorphometry. Bone mineral content was measured by osteometry. RESULTS: Osteometric and osteomorphometric data (trabecular bone volume [%], assessment of chromatin staining, and an osteocyte index) registered for the biopsy specimens were not statistically correlated with implant failure. CONCLUSIONS: Prognostic evaluation of implant survival is difficult. The tested methods did not contribute to the improvement of guidelines for the clinical handling of these patients.     

Complications of motility peg placement for the hydroxyapatite orbital implant

PURPOSE: The hydroxyapatite implant is an ocular motility implant designed to provide natural movement of the artificial eye. The movement of the prosthesis is maximized when the implant is coupled to the prosthesis via a peg. The purpose of this study is to determine the complications of the hydroxyapatite motility peg and the factors related to those complications. DESIGN: Retrospective review of 47 cases over 5 years. METHODS: A retrospective review was performed on all cases of hydroxyapatite motility peg placement. The technique of hydroxyapatite and peg placement, follow-up details, and complications of the peg were recorded. RESULTS: The complications of peg placement included peg extrusion in 26% (12 of 47), nonspecific conjunctivitis in 6% (3 of 47), audible click in 6% (3 of 47), temporary excessive conjunctival edema in 4% (2 of 47), and temporary excessive postoperative pain in 4% (2 of 47). There were no cases of infection, persistent pain, persistent edema, or discharge at peg site. The median time interval from peg placement to extrusion was 16 months (range, 1-52 months). The only statistically significant factor related to peg extrusion was age over 50 years (P = 0.04). There was a trend toward peg extrusion with use of a nonsleeved peg (versus sleeved peg) (P = 0.10). The extrusion rate was 32% (12 of 38) for nonsleeved pegs and 0% (0 of 9) for sleeved pegs. Factors unrelated to peg extrusion were patient sex, prior ocular surgery or radiotherapy, presence of giant papillary conjunctivitis, time interval from enucleation to peg placement, and degree of implant vascularization on magnetic resonance imaging. Of the 12 nonsleeved pegs that extruded, a sleeved peg system was subsequently successfully placed in 5 patients, a nonsleeved peg in 1 patient, and 6 patients remained without a peg system. CONCLUSIONS: Hydroxyapatite motility pegs have relatively few complications except for extrusion. The rate of extrusion can be minimized by employing a sleeved peg rather than a nonsleeved peg system.     

The use of osteotomes for sinus augmentation at the time of implant placement

The placement of endosseous dental implants is often hampered by the loss of alveolar bone. In the posterior maxilla, the presence of the maxillary sinus and less-dense bone present additional obstacles to successful implant placement. Existing methods of subantral augmentation require extensive surgical manipulation, often including a second surgical site for harvesting autogenous bone. The development of surgical osteotomes has facilitated the placement of implants in areas of minimal alveolar bone height in the posterior maxilla. This article describes the osteotome technique for sinus augmentation at the time of implant placement and presents a short-term evaluation of 34 implants placed in 18 patients.     

Paradoxical response to photorefractive treatment for postkeratoplasty astigmatism

Traditionally, the procedure of implant placement requires a surgical periosteal flap to be raised. In a percentage of implant cases, there is no need for flap surgery for implant placement, or for a follow-up surgical procedure for abutment connection. In this clinical investigation, 20 maxillary and mandibular implants were placed in seven adult male patients. The sites for implant placement were prepared according to an alternative surgical technique without raising a surgical flap. Patients were recalled periodically for 2 years to evaluate healing and clinical integration of implants. The results showed normal clinical healing at the first week of reexamination in all implant sites; periodontal probing of less than 2 mm circumferentially around all healing caps at 3 months and later at subsequent recall periods; no radiolucency observed in the peri-implant zone; no sign of clinical mobility during recall examination; and no persistent or irreversible sign or symptoms of pain, infection, or necrosis. This alternative surgical technique can provide several advantages over the traditional 2-step procedure.     

Permanent endoprostatic prostheses in patient with obstruction caused by benign hyperplasia of the prostate

Presentation of the results obtained using the intraprostatic prosthesis UroLume in 78 patients wit BPH obstruction, 69 of which presented high surgical risk (ASA IV). Mean age was 79.8 years (r: 62-93). All patients carried urethral catheters, except 4 (5.1%) who had a provisional metal coil that required replacement. Prosthesis were implanted successfully in 72 cases (93.3%). The most significant exclusion criterion was an excessive length of prostate urethra. Mean follow-up was 15.3 months (r: 3-38). Mean maximum flow at 1 year after implant was 12.7 mL/sec; mean symptoms score (I-PSS score) was 6.2 points and in most prosthesis, epithelization had taken place. Three patients required implant of another prosthesis, either during the same surgical procedure (1 case) or later due to retention or dysuria (2 cases). Due to acute urine retention (AUR) during the immediate postoperative, resection of the middle lobe was performed in one case while a second case required late resection of intraluminal hyperplastic tissue. Three patients (4.1%) had haematuria that forced hospital admission some months after the implant, and three cases (4.1%) required removal of the prosthesis; at patient's request (1 case), due to calcification (1 case) and for stress incontinence (1 case). After a follow-up of over three years, it can be concluded that the UroLume prosthesis is an effective alternative to TUR in patients at high surgical risk.     

Two applications of transmucosal milled ceramic in implantology: preliminary clinical examples

Two new implant systems, the Compound Implant and the TFM coping/abutment, are based on the association of titanium in the infrabony portion and a dense milled ceramic in the transgingival portion. The coating of zirconium ceramic on the transmucosal collar of the Compound Implant is particularly indicated for a single-stage surgical implant technique. The isolating properties and the high wettability of this material favor gingival healing and reduce the accumulation of plaque; the esthetic collar permits a supragingival or juxtagingival cervical margin favoring plaque control and minimizing the consequences of tissue remodeling. The hardness of the ceramic also allows it to undergo conventional prophylaxis with ultrasonic scalers without alteration of its surface quality. In addition to the above-mentioned advantages, the TFM coping/abutment, an implant-prosthesis connector in alumina ceramic, for use in a two-stage technique, provides electrogalvanic isolation of the implant, and personalized abutment preparation allows for simplified fabrication of an implant-supported prosthesis.     

Cat scratch disease and AIDS

The success of a bar superstructure for an orbital prosthesis may be compromised by the placement and angulation of implants. The following technique describes a modification to a bar superstructure that provided the advantages of convenience, security, and consistent positioning even though one implant was lost and the angulation of implants limited accuracy.     

Improving outcomes using dental implants: integrating improvements in clinical practice

Modern restorative dentistry is confronted with many challenges related to implant use in the craniofacial region, such as attempting to place implants in esthetically critical sites or anatomically limiting regions of the jaw. To assure a successful implant placement that is satisfactory to both the patient and the dentist, four key areas need to be improved: diagnostic procedures, surgical procedures and outcomes, esthetic results, and prosthetic complications. This article discusses how an integrated approach to these areas can improve clinical practice.     

"Flocculus neonatorum": a self-resolving benign nodular flocculus of the iris in the newborn

A severely resorbed maxilla was reconstructed utilizing a combined surgical technique that included the placement of a horseshoe-shaped bicortical calvarium onlay graft, fixed by six endosseous implants. Two more implants were placed in the pterygoid process to support and stabilize the prosthesis. The dentition was rehabilitated with a fixed implant-supported hybrid prosthesis.     

Survival from massive intraoperative pulmonary thromboembolism during orthotopic liver transplantation

The placement of glaucoma drainage implants may be complicated by tube-corneal touch and endothelial decompensation, particularly after corneal transplantation. We describe an innovative surgical approach to glaucoma drainage implant procedures that may decrease such complications. The approach involves placement of the shunt tube into the ciliary sulcus. This approach may serve as an alternative to anterior chamber angle or pars plana implant placement in pseudophakic or aphakic eyes with refractory glaucoma and a high risk for corneal decompensation.     

Poor results following internal fixation of displaced subcapital femoral fractures: complacency in fracture reduction

The results following internal fixation of displaced subcapital femoral fractures are poorer than for undisplaced fractures and are determined by both the quality of the initial reduction and the accuracy of implant placement. In a series of 26 consecutive displaced fractures internally fixed with Richards hip pins, satisfactory reduction was achieved in only 15 hips. Accurate reduction is a prerequisite for correct screw placement and occurred in only 4 of the 11 poorly aligned fractures, as opposed to 11 of the 15 well reduced ones. A total of 10 hips required a further surgical procedure as the result of complications. These results highlight the importance of accurate fracture reduction in facilitating implant placement as well as the importance of good surgical technique rather than reliance purely upon the implant. These already common fractures are assuming increasing socioeconomic importance as the elderly population grows, and successful management is vital for both the individual patient and future demands on the health service.