Implants In Conjunction Research Articles

Zygomatic Implant Placement in Conjunction with Sinus Bone Grafting: The “Extended Sinus Elevation Technique.” A Case-Cohort Study

The zygomatic implant is mainly indicated for the rehabilitation of extremely atrophied maxillae when bone augmentation should be avoided. One drawback of zygomatic implants, which typically pass through the sinus, is initial or late bone resorption around the implant neck, which can result in oroantral communications followed by possible infection of the sinus. To decrease the risk of sinus infection, a modified technique was developed to preserve the integrity of the sinus membrane and to regenerate bone around zygomatic implants using an extended sinus grafting approach. Patients with extremely atrophied maxillae were provided with one to four zygomatic implants in conjunction with sinus grafting, plus conventional auxiliary implants, for immediate support of a provisional full-arch maxillary prosthesis. Definitive prostheses were delivered at 6 months after implant placement. All patients underwent clinical and radiographic examinations at 6 months. Twenty-two zygomatic and 23 conventional auxiliary implants were placed in 10 patients. The overall 6-month implant survival rate was 90.9% for zygomatic implants and 100% for auxiliary implants placed in the anterior area. Only two minor technical complications were seen, and clinical indicators (including probing pocket depth, keratinized tissue, and plaque and bleeding indices) were good in all patients. A substantial gain of radiographic bone around the zygomatic implants was observed. The proposed technique led to successful prosthetic function for all patients. With the described technique, exposed implant threads within the maxillary antrum are eliminated and the potential for biologic complications is minimized.

Zygomatic implant‐retained fixed complete denture for an elderly patient

Dental rehabilitation of a completely edentulous geriatric patient has always been a challenge to the clinician, especially in treating those with higher expectations and demands. Treatment duration and the amount of residual alveolar bone available are often important considerations when planning for dental implant-based fixed treatment for these patients. With the introduction of zygomatic implants, a graftless alternative solution has emerged for deficient maxillary bone with provision for immediate loading. This article describes the treatment of a completely edentulous elderly patient using zygomatic implants in conjunction with conventional implants. The implants were immediately loaded using a definitive acrylic resin fixed denture reinforced with a cast metal framework, to provide function and aesthetics.

Implants in conjunction with removable partial denture

The benefits of implant supported overdenture are readily apparent for the fully edentulous patients and have been well documented, however, there is deficiency of the studies regarding the combination of implants with removable partial dentures for partially edentulous patients. The purpose of this article is to review the literature concerning implants with removable partial dentures and evaluate the evidence for this clinical approach. Through many clinical case reports and studies we have searched from a broad variety of journals, we present the six considerations needed to contemplate respecting implants with removable partial denture in partially edentulous patients. First, the connection between abutment tooth and removable partial denture has to be rigid and the link between implant and removable partial denture should be hinged. Second, a mesial rest acts better in the point of force distribution for distal extension removable partial denture and splinting between implants is also a favorable choice. Third, T bar has an advantage for implants which are used as abutments in distal extension removable partial denture. Forth, as we all known functional impression is better way to reproduce movement for distal extension removable partial denture. Fifth, indirect retainer and guiding plane on the proximal surfaces of terminal abutment teeth are important in preventing denture base lifting. Sixth, implants in conjunction with removable partial denture is superior in the esthetic and phonetic as well as cost-effective point of view. We also suggest that which place we should install implants for force distribution and which diameter and length of implants should be used. in this review article, we recommend to locate the implant near of the abutment tooth for esthetics or near of first molar position for good stress distribution. The diameter and length of implant also influence to stress distribution. When we compare to conservative partial denture, patients go for removable partial denture using implants due to convenience, better support and retention according to several studies. But it is true that we need to study more on this subject and collect long term follow up cases before we discuss on it. So it is enough to bring this subject into the surface of prosthetic treatment by this article.

Replacement of Vertically Root-Fractured Endodontically Treated Teeth With Immediate Implants in Conjunction With a Synthetic Bone Cement

The purpose of this prospective study was to evaluate the clinical outcome of implants immediately placed into fresh extraction sockets for the replacement of endodontically treated teeth with signs of vertical root fracture. Sixteen partially edentulous patients, with 1 tooth scheduled for extraction and showing clinical signs and symptoms and/or radiological evidence of vertical root fracture, were included in the study. Sixteen transmucosal implants were installed immediately after extraction and careful debridement. The gap between the implant surface and the socket walls was filled using synthetic bone grafting cement. Prosthetic phase occurred 3 to 4 months after surgery. Implant success and survival and radiographic bone loss were evaluated after 1 year of function. Patient satisfaction for mastication function, phonetics, and aesthetics was also assessed by means of a questionnaire. No implant failure occurred. The overall implant success and survival was 100% at 1 year. The mean follow-up was 13.5 months. All prostheses were successful. Periimplant bone loss after 1 year averaged 0.48 ± 0.20 mm. All patients reported full satisfaction for mastication function, phonetics, and aesthetics. The use of a synthetic bone grafting cement in combination with immediate implant placement procedure can be considered a safe, effective, and predictable treatment option for the rehabilitation of fresh postextraction sockets.

Mandibular Fracture in Conjunction with Bicortical Penetration, Using Wide‐Diameter Endosseous Dental Implants

Prosthodontic rehabilitation of a patient with an atrophic edentulous mandible presents a significant challenge in restoring esthetics and function. The purpose of this clinical report is to describe fracture of an atrophic edentulous mandible opposing maxillary natural dentition in association with endosseous dental implants. The patient received two wide-diameter implants in the anterior mandible for an implant-assisted mandibular overdenture, in which the implants penetrated the inferior border of the mandible for bicortical stabilization. Three months following implant placement surgery, the patient experienced pain, swelling, and intraoral purulent drainage around the right implant. Panoramic radiograph revealed a fracture of the mandible through the right implant site and signs of infection around the left implant. The implants were removed surgically, and open reduction and fixation of the fracture site were undertaken using a titanium bone fixation plate. This clinical report demonstrates that placement of wide-diameter implants in conjunction with bicortical penetration in a severely atrophic edentulous mandible can risk fracture of the mandible.

Simplifying the Implant Treatment Plan for an Elderly Patient

In the search for a better lifestyle and increased life expectancy, more and more elderly are seeking dental treatment. However, many of these patients present systemic compromise that could affect the success and maintenance of the proposed therapy. In such cases, simple proposals, such as partial removable prostheses (PRPs), must be used. PRPs are widely used, especially when conditions for rehabilitation with a fixed prosthesis attached to implants are not favorable.1In one study,2 10 patients were rehabilitated with inferior PRPs supported by implants in the posterior region; results show increased satisfaction in all patients, minimal wear of the component, absence of excessive bone loss, and periodontal health after 1 year of rehabilitation.Literature describing the combination of PPRs and implants is scarce and is based mainly on clinical reports of posterior implants for distal extension with PRPs.3,4 In this case, rehabilitation with fixed prostheses and implants was proposed to the patient, who required surgically guided bone regeneration through subantral graft or PRPs, but the patient declined both proposals. Following this, rehabilitation with implants in conjunction with PRP was planned and proposed to avoid subjecting the patient to sinus lifting surgery and to preserve the remaining tooth and the residual ridge; however, the team explained that greater load would be generated on these if they received only PRPs.A 71-year-old male patient with controlled hypertension and presenting with dental phobia inquired about dental implants, seeking to improve both esthetics and function.During the planning stage, the need for surgery to achieve maxillary sinus lifting was observed if rehabilitation with a fixed prosthesis on implants was chosen (Figures 1 and 2). However, following the clinical examination and according to patient history, planning was directed toward simplified rehabilitation, also involving implants, but associated with PRP. This solution rehabilitated the patient within his functional and esthetic expectations without subjecting him to greater stress.Following initial procedures of restorative care, the surgical implantology step was initiated, during which the region of missing elements 15, 22, 24, 36, and 46 received Cone Morse implants. After 4 months, implanted regions were reopened with placement of the healings. Then the prosthetic components were selected, highlighting the region of elements 24 and 25, which received o-ring abutment (Figure 3).The proposed therapy considered the patient's complaint, his systemic framework, and his response to invasive events, given that he reported high levels of fear and anxiety. The treatment approach was preventive, based on maintenance of blood pressure without systemic risks to the patient, by not indicating surgery for maxillary sinus lifting. The patient received 5 implants, and the top 2 retainers were PRP o-rings (Figures 4 and 5).In rehabilitation with PRPs, viscoelastic tissue, alveolar mucosa, and teeth must be properly evaluated because they serve as support structures. When rehabilitation is associated with osseointegrated implants, which provide the support line between these pillars and edentulous areas in classes I and II of Kennedy situations, survival can be compromised by functional overload.5 However, when implants are used only to retain the PRP, the current consensus is that support, retention, and stability of PPRs are improved without overload and without the need for conventional clips.Follow-up of 1 year shows that the impact of treatment was well absorbed by the tissues, allowing the original treatment plan to be maintained (Figures 6 and 7).It was possible to establish a comfortable situation, both esthetically and functionally, without creating more fear and anxiety in the patient, because greater intervention, such as sinus lifting and grafting, was not required, resulting in satisfactory treatment at a lower cost with less stress and over a shorter time.

Fixed rehabilitation of patient with aggressive periodontitis using zygoma implants

Treatment of patients with aggressive periodontitis has always been a challenge to the clinician. Both young and old are known to be affected by this progressive destructive condition of the supporting dental structures. Although dental implants have been offered as a viable treatment alternative for such patients, additional procedures (like bone grafting) and delayed protocols have limited their usage. This case report describes the treatment of a young patient with aggressive periodontitis using a graftless implant solution. Zygoma implants in conjunction with conventional implants were used with immediate loading.

Experimental immediate loading of dental implants in conjunction with grafting procedures.

The aim of this study was to evaluate immediate loading (IL) of dental implants in conjunction with grafting procedures. A total of 107 IL implants were inserted in six mini pigs. Before implant placement, crestal or apical defects were created, which were treated with bone chips, phycogene hydroxyapatite (HA), bovine HA, or bovine HA enhanced with a synthetic peptide. Crestal grafts were stabilized with titanium membranes. All bridges were in function and showed signs of chewing wear after 4-month loading. Three out of 107 implants showed no osseointegration (2.7%). Most of the crestal defects showed incomplete regeneration, due to an infection of the membranes (74.3%) The difference in height between surgical and remaining defect was calculated as defect development, which was 2.3 +/- 2.08 mm for bone chips with an area of regenerated bone of 22.8 +/- 3.34% and 0.7 +/- 2.22 mm for phycogene HA with 11.3 +/- 4.36% regenerated bone. Bovine HA showed an increase of defects 1.3 +/- 2.47 mm with only 7.9 +/- 1.7% bone regeneration. Bovine HA enhanced with a peptide showed a defect development of 1.1 +/- 1.42 mm with an area of regenerated bone of 18.2 +/- 2.38%. In conclusion, local grafting procedures did not disturb the course of osseointegration for immediate loaded implants if primary stability was reached. The regeneration of apical defects was uneventful even with immediate loading. Crestal defects required membrane fixation with a careful flap elevation to avoid membrane exposure and loss of the graft.

Implants in Conjunction With Removable Partial Dentures: A Literature Review

Although the benefits of implant-borne removable prostheses are readily apparent for the fully edentulous patient and have been well documented, there is a paucity of studies concerning the combination of implants with removable partial dentures in partially edentulous patients. The aim of this article is to review the literature regarding implants with removable partial dentures and evaluate the evidence for this clinical approach. A MEDLINE/PubMed search from 1990 to 2006, focusing on the use of implants with removable partial dentures and related features, was supplemented with a hand search to identify relevant peer-reviewed English articles published in dental journals and textbooks on removable partial dentures.

CHITOSAN-GLYCEROL PHOSPHATE/BLOOD IMPLANTS IMPROVE HYALINE CARTILAGE REPAIR IN OVINE MICROFRACTURE DEFECTS

Background: Microfracture is a surgical procedure that is used to treat focal articular cartilage defects. Although joint function improves following microfracture, the procedure elicits incomplete repair. As blood clot formation in the microfracture defect is an essential initiating event in microfracture therapy, we hypothesized that the repair would be improved if the microfracture defect were filled with a blood clot that was stabilized by the incorporation of a thrombogenic and adhesive polymer, specifically, chitosan. The objectives of the present study were to evaluate (1) blood clot adhesion in fresh microfracture defects and (2) the quality of the repair, at six months postoperatively, of microfracture defects that had been treated with or without chitosan-glycerol phosphate/blood clot implants, using a sheep model. Methods: In eighteen sheep, two 1-cm2 full-thickness chondral defects were created in the distal part of the femur and treated with microfracture; one defect was made in the medial femoral condyle, and the other defect was made in the trochlea. In four sheep, microfracture defects were created bilaterally; the microfracture defects in one knee received no further treatment, and the microfracture defects in the contralateral knee were filled with chitosan-glycerol phosphate/autologous whole blood and the implants were allowed to solidify. Fresh defects in these four sheep were collected at one hour postoperatively to compare the retention of the chitosan-glycerol phosphate/blood clot with that of the normal clot and to define the histologic characteristics of these fresh defects. In the other fourteen sheep, microfracture defects were made in only one knee and either were left untreated (control group; six sheep) or were treated with chitosan-glycerol phosphate/blood implant (treatment group; eight sheep), and the quality of repair was assessed histologically, histomorphometrically, and biochemically at six months postoperatively. Results: In the defects that were examined one hour postoperatively, chitosan-glycerol phosphate/blood clots showed increased adhesion to the walls of the defects as compared with the blood clots in the untreated microfracture defects. After histological processing, all blood clots in the control microfracture defects had been lost, whereas chitosanglycerol phosphate/blood clot adhered to and was partly retained on the surfaces of the defect. At six months, defects that had been treated with chitosan-glycerol phosphate/blood were filled with significantly more hyaline repair tissue (p < 0.05) compared with control defects. Repair tissue from medial femoral condyle defects that had been treated with chitosan-glycerol phosphate/blood contained more cells and more collagen compared with control defects and showed complete restoration of glycosaminoglycan levels. Conclusions: Solidification of a chitosan-glycerol phosphate/blood implant in microfracture defects improved cartilage repair compared with microfracture alone by increasing the amount of tissue and improving its biochemical composition and cellular organization. Clinical Relevance: The use of chitosan-glycerol phosphate/blood implants in conjunction with microfracture can improve the structural and compositional properties of repaired cartilage. These effects may result in better integration, improved biomechanical properties, and longer durability of the repair tissue.

Chitosan-Glycerol Phosphate/Blood Implants Improve Hyaline Cartilage Repair in Ovine Microfracture Defects

Microfracture is a surgical procedure that is used to treat focal articular cartilage defects. Although joint function improves following microfracture, the procedure elicits incomplete repair. As blood clot formation in the microfracture defect is an essential initiating event in microfracture therapy, we hypothesized that the repair would be improved if the microfracture defect were filled with a blood clot that was stabilized by the incorporation of a thrombogenic and adhesive polymer, specifically, chitosan. The objectives of the present study were to evaluate (1) blood clot adhesion in fresh microfracture defects and (2) the quality of the repair, at six months postoperatively, of microfracture defects that had been treated with or without chitosan-glycerol phosphate/blood clot implants, using a sheep model. In eighteen sheep, two 1-cm2 full-thickness chondral defects were created in the distal part of the femur and treated with microfracture; one defect was made in the medial femoral condyle, and the other defect was made in the trochlea. In four sheep, microfracture defects were created bilaterally; the microfracture defects in one knee received no further treatment, and the microfracture defects in the contralateral knee were filled with chitosan-glycerol phosphate/autologous whole blood and the implants were allowed to solidify. Fresh defects in these four sheep were collected at one hour postoperatively to compare the retention of the chitosan-glycerol phosphate/blood clot with that of the normal clot and to define the histologic characteristics of these fresh defects. In the other fourteen sheep, microfracture defects were made in only one knee and either were left untreated (control group; six sheep) or were treated with chitosan-glycerol phosphate/blood implant (treatment group; eight sheep), and the quality of repair was assessed histologically, histomorphometrically, and biochemically at six months postoperatively. In the defects that were examined one hour postoperatively, chitosan-glycerol phosphate/blood clots showed increased adhesion to the walls of the defects as compared with the blood clots in the untreated microfracture defects. After histological processing, all blood clots in the control microfracture defects had been lost, whereas chitosanglycerol phosphate/blood clot adhered to and was partly retained on the surfaces of the defect. At six months, defects that had been treated with chitosan-glycerol phosphate/blood were filled with significantly more hyaline repair tissue (p < 0.05) compared with control defects. Repair tissue from medial femoral condyle defects that had been treated with chitosan-glycerol phosphate/blood contained more cells and more collagen compared with control defects and showed complete restoration of glycosaminoglycan levels. Solidification of a chitosan-glycerol phosphate/blood implant in microfracture defects improved cartilage repair compared with microfracture alone by increasing the amount of tissue and improving its biochemical composition and cellular organization.

Dental implants placement in conjunction with osteotome sinus floor elevation: a 12‐year life‐table analysis from a prospective study on 588 ITI®implants

The purpose of this prospective study was to evaluate the clinical success of placing ITI dental implants in the posterior maxilla using the osteotome technique. All implants were placed following a one-stage protocol (elevating the sinus floor and placing the implant at the same time). Five hundred and eighty-eight implants were placed in 323 consecutive patients with a residual vertical height of bone under the sinus ranging from 6 to 9 mm. The mean observation follow-up period was 59.7 months (with a range of 12-144 months). This prospective study not only calculated the 12-year cumulative survival and success rates for 588 implants by life-table analysis but also the cumulative success rates for implant subgroups divided per implant length and the percentage of sinus membrane perforation were evaluated. The 12-year cumulative survival and success rates were 94.8% and 90.8%, respectively. The analysis of implant subgroups showed slightly more favourable cumulative success rates for 12 mm long implants (93.4%) compared with 10 and 8 mm long implants (90.5% and 88.9%, respectively). During the study period, only 13 perforations of the Schneiderian membrane were detected with a perforation rate of 2.2% (13 perforations/601 treated sites). Ten perforations out of 13 were caused during the first half of the study period and of these, seven were detected during the first 3 years of this prospective study. Based on the results and within the limits of the present study, it can be concluded that ITI implant placement in conjunction with osteotome sinus floor elevation represents a safe modality of treating the posterior maxilla in areas with reduced bone height subjacent to the sinus as survival and success rates were maintained above 90% for a mean observation period of approximately 60 months. Shorter implants (8 mm implants) did not significantly fail more than longer ones (10 and 12 mm implants): the differences were small compared with the number of events; hence, no statistical conclusion could be drawn. But, from the clinical point of view, the predictable use of short implants in conjunction with osteotome sinus floor elevation may reduce the indication for complex invasive procedures like sinus lift and bone grafting procedures.

Spoken Word Recognition Development in Children with Residual Hearing Using Cochlear Implants and Hearing Aids in Opposite Ears

With broadening candidacy criteria for cochlear implantation, a greater number of pediatric candidates have usable residual hearing in their nonimplanted ears. This population potentially stands to benefit from continued use of conventional amplification in their nonimplanted ears. The purposes of this investigation were to evaluate whether children with residual hearing in their nonimplanted ears benefit from bilateral use of cochlear implants and hearing aids and to investigate the time course of adaptation to combined use of the devices together. Pediatric cochlear implant recipients with severe sensorineural hearing loss in their nonimplanted ears served as participants. Ten children continued to use hearing aids in their nonimplanted ears after cochlear implantation; 12 children used their cochlear implants exclusively. Participants were tested longitudinally on spoken word recognition measures at 6-month intervals. The children who continued wearing hearing aids were tested in three sensory aid conditions: cochlear implants alone, hearing aids alone, and cochlear implants in conjunction with hearing aids. The children who did not continue hearing aid use were tested after surgery in their only aided condition, cochlear implant alone. The results suggest that children with severe hearing loss who continued using hearing aids in their nonimplanted ears benefited from combining the acoustic input received from a hearing aid with the input received from a cochlear implant, particularly in background noise. However, this benefit emerged with experience. Our findings suggest that it is appropriate to encourage pediatric cochlear implant recipients with severe hearing loss to continue wearing an appropriately fitted hearing aid in the nonimplanted ear to maximally benefit from bilateral stimulation.

A New Method to Harvest Ramus Bone Using the Erbium, Chromium:Yttrium-Scandium-Gallium-Garnet Laser

Autogenous, monocortical block grafts are used extensively in alveolar ridge augmentation prior to implant placement. The main indication is either a defect or atrophy in the anteroposterior or buccolingual dimension, which will prevent implant placement. Donor sites available for implant reconstruction have been described in the literature. Extraoral donor sites such as the ilium, 1 Keller E.E. vanRoekel N.B. Desjardins R.P. et al. Prosthetic-surgical reconstruction of the severely resorbed maxilla with iliac bone grafting and tissue-integrated prostheses. Int J Oral Maxillofac Implants. 1987; 2: 155 PubMed Google Scholar calvaria, 2 Cain J.R. Mitchell D.L. Markowitz N.R. et al. Prosthodontic restoration with dental implants and an intraoral cranial bone onlay graft A case report. Int J Oral Maxillofac Implants. 1993; 8: 98 PubMed Google Scholar , 3 Donovan M.G. Dickerson N.C. Hanson L.J. et al. Maxillary and mandibular reconstruction using calvarial bone grafts and Branemark implants A preliminary report. J Oral Maxillofac Surg. 1994; 52: 588 Abstract Full Text PDF PubMed Scopus (103) Google Scholar clavicle, 4 Listrom R.D. Symington J.M. Osseointegrated dental implants in conjunction with bone grafts. Int J Oral Maxillofac Implants. 1988; 17: 116 Abstract Full Text PDF Scopus (108) Google Scholar and scapula 5 Buchbinder D. Urken M.L. Vickery C. et al. Functional mandibular reconstruction of patients with oral cancer. Oral Surg Oral Med Oral Pathol. 1989; 68: 499 Abstract Full Text PDF PubMed Scopus (53) Google Scholar require hospitalization and are not without potential morbidity. The tibia is not recommended, as only cancellous bone is available in satisfactory amounts for grafting procedures. 6 Lee C.Y.S.L. An in-office technique for harvesting tibial bone Outcomes in 8 patients. Oral Implantol. 2003; 29: 181 Crossref Google Scholar Intraoral ramus grafts from the mandible have also been used and should be the primary harvest site when possible. Advantages are reduced in-office operative and anesthesia time, low morbidity, and ease of surgical access, which can be accomplished under local anesthesia or intravenous sedation. For the young patient who has not had the mandibular third molars removed, harvesting of ramus grafts with simultaneous removal of the third molar should also be considered, as only one surgical procedure is required. The armamentarium to harvest bone from the ramus of the mandible is usually a fissure bur in a high-speed handpiece or oscillating saw. The purpose of this article is to introduce a new alternative method to harvest ramus bone from the mandible using the latest generation laser, the erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser.

Gross growth and regrowth of sutures: reflections on some personal research.

A series of experiments was performed on young monkeys, rabbits, and turtles to study gross sutural growth of bones. Radiopaque implants in conjunction with serial, direct gross, and indirect radiographic measurements were employed. Differences in growth were observed in the monkey among five facial sutures and also the same suture at different times. Growth was greatest at the zygomaticotemporal suture and least at the premaxillomaxillary suture. In the rabbit, the nasal bone side of the frontonasal suture grew about twice as fast as the frontal bone side. In the turtle shell, the midsagittal suture grew faster than the transverse suture. In all of the animals, the rate of sutural growth decreased with an increase in age. No gross regional growth disturbance was noted after resection of the frontonasal, midpalatine, or transpalatine sutures. The frontonasal suture reformed presumably because of the underlying nasomucoperiosteum, as in a cranial suture, presumably because of the underlying dura. After extirpation of the midpalatine suture with the formation of a complete cleft and despite no underlying membrane, a new suture reformed in an eccentric position in a number of instances. Bone growth at sutures is secondary or compensatory to some other factors.

Application of titanium-alloy endodontic implants in conjunction with periradicular surgery

Objective. To evaluate the outcome of placement of titanium-alloy endodontic implants in conjunction with periradicular surgery. Study design. Twenty-four teeth were treated with endodontic implants with corresponding periradicular surgery by using SuperEBA cement (Harry J Bosworth Co, Skokie, Ill) as a sealer. The results of the endodontic implant surgery were evaluated clinically and radiographically from 2 to 4 years after treatment. Results. Twenty-two teeth were treated successfully, whereas 2 teeth were treated unsuccessfully, for a success rate of 92%. Conclusions. Titanium-alloy endodontic implants in conjunction with periradicular surgery may provide good short-term results. Sealing between the endodontic implant and the dentin is likely an important factor for success. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1999;88:484-7)

Maxillary sinus augmentation using different grafting materials and dental implants in monkeys. Part IV. Evaluation of hydroxyapatite-coated implants.

The aim of this study was to evaluate clinically, histologically and histometrically the use of hydroxyapatite-coated dental implants in conjunction with maxillary sinus augmentation procedures. In 4 adult male Rhesus monkeys (Macaca mulatta) the 3 maxillary molars on 1 side of the jaws were extracted and the remaining bone between the alveolar crest and the floor of the sinus was reduced to 3-4 mm. After 3 months, maxillary sinus augmentation procedures were performed in each monkey and the sinuses were grafted with a porous hydroxyapatite bone graft (Interpore-200). At the same time, 2 hydroxyapatite-coated cylinder implants (IMZ) were immediately placed into the augmented sinuses (i.e. simultaneous-implants-loaded group). Four months later, 2 additional similar implants were placed into the previously augmented sinuses (i.e. delayed-implants-loaded group). After 4 months, the abutment connection was performed and all 4 implants were loaded with a gold-alloy bridge for 6 months (i.e. until sacrifice of the animals). The contralateral side of each monkey received the same treatment with the exception that removal of the maxillary molars was performed 7 months after those in the opposite side, and that the implants in this side were not loaded. Thus, 2 additional study groups (i.e. simultaneous-implants-unloaded group and delayed-implants-unloaded group) were obtained. Clinically, all loaded and unloaded implants were stable the day of sacrifice. Histologically, the grafted sinuses exhibited a significant amount of new bone formation with integration of the porous hydroxyapatite graft particles and hydroxyapatite-coat of the dental implants to the new bone. Histometric analysis indicated that on the loaded side the implants placed simultaneously with the sinus lift procedure exhibited greater direct mineralized bone-to-implant contact than the delayed placed implants. In addition, the percentage of direct mineralized bone-to-implant contact was significantly greater in the residual bone in comparison to the augmented area in all groups. Loading of the implants exhibited a positive effect on the percentage of direct mineralized bone-to-implant contact in the augmented area. It could be concluded that hydroxyapatite-coated implants may be of benefit when used in conjunction with sinus augmentation procedures.

Intraoperative interstitial iridium brachytherapy in the management of soft tissue sarcomas: preliminary results of a feasibility phase II study

Between May 1986 and June 1992, 48 patients with soft tissue sarcomas underwent 50 intraoperative interstitial implants in conjunction with conservative tumoral resections. Brachytherapy was part of the initial treatment in 27 cases and was done in 21 other previously treated patients. For the last ones brachytherapy was, in most of the cases, the only treatment in addition to surgery. The implant dose was 40–65 Gy. When combined with external irradiation the mean prescribed dose was 20 Gy (12–25 Gy). With a median follow-up of 33 months, the 3-year actuarial survival rate was 81% and the local disease-free survival 91.7%. Five local failures were observed only in patients with recurrent sarcomas: two were inside the treated volume and three outside (local failure 5 48 = 10.4% ). Acute side-effects occurred in 11 patients ( 11 48 = 23% ), with skin breakdown (two cases) infection and hematoma (one case), infection, lymphocele, secondary skin breakdown and vascular rupture (one case), infection and limited skin breakdown (two cases) and delayed healing (five cases). As a consequence, six patients required reoperation but no amputation was necessary. The functional results were good. Only three patients had a moderate limitation of movement. Late complications occurred in five patients: bone fracture (one case), leg oedemas not interfering with normal activity (three cases), peripheral neuropathy fibrosis related requiring surgery (one case). Therefore, this preliminary report shows that adjuvant intraoperative brachytherapy is feasible and is safe in treating soft tissue sarcomas, even in previously irradiated patients. However, further evaluation is needed to determine the real place of intraoperative implant in the management of soft tissue sarcomas.

Early results from reconstruction of severely atrophic (class VI) maxillas by immediate endosseous implants in conjunction with bone grafting and Le Fort I osteotomy

This report presents our experience with 12 consecutive patients treated by the method of Sailer19, comprising bone grafting to the floor of the nose and the maxillary sinus after a Le Fort I inferior repositioning of the maxilla followed by immediate implantation of endosseous implants. The corticocancellous grafts were harvested from the iliac crest. Fifty-nine implants were inserted in the bone grafts and eight in the adjacent nongrafted bone. Fourteen implants (21%) had to be removed because of nonintegration, of which 10 had been placed in two patients. The follow-up ranged from 11 to 24 months. No implants have been lost after loading. Six patients received fixed prostheses, and four overdentures. The importance of complete peroperative positional stability of the bone grafts and implants is emphasized.

骨移植とインプラント義歯による高度上顎歯槽堤萎縮症の治療

Osseointegrated implants are currently recognized to be effective when used in preprosthetic surgery. Simultaneous bone grafting procedures to treat severely atrophic maxillae has, however, been little reported. Surgical procedures vary depending on the site and extent of bone resorption and bone quality; therefore, surgical planning should be carefully executed.We have simultaneously placed osseointegrated implants in conjunction with bone grafting in 9 of 10 extremely absorbed maxillae. In this report, the clinical course of alveolar bone resorption around the fixtures, survival rate of the installed fixtures, and masticatory efficiency in relation to surgical procedure were discussed.1. The patients consisted of nine females and one male, ranging in age from 16 to 58 years.2. A total of 59 fixtures were placed. In totally edentulous cases, six to eight fixtures were placed. In partially edentulous cases, two to five fixtures were placed. Four fixtures failed to achieve osseouintegration. Mean overall survival rate was 93.2% for a 1.5 year followup period.3. The degree of bone resorption was 0.6 mm in 6 months, and 1.0 mm in one year after initial surgery. After the first year, bone resorption rate is stabilized at 0.2 mm per year.4. Regarding masticatory efficiency assessed pre-and post operatively, all of the cases showed extreme improvement. The mean masticatory score in totally edentulous cases was 32 points preoperative and 92.5 points postoperative; that in partial edentulous cases was 44 points preoperative and 97.5 postoperative.These results indicate that osseointegrated implants in conjunction with bone grafting is a satisfactory procedure to restore masticatory function in patients with extreme atrophic maxillae.