Primary insertion of osseointegrated dental implants into fibula osteoseptocutaneous free flap for mandible reconstruction

Twelve patients with segmental mandibular defects were reconstructed with fibula osteoseptocutaneous flaps and simultaneous placement of osseointegrated implants. Decision to perform this procedure was based on the facts that all patients had benign diseases, did not require postoperative radiotherapy, were in good general and oral conditions, and were psychologically motivated. A total of 34 fixtures was inserted in the first stage. Eight patients underwent second stage surgery, which consisted of connection of the implant abutments to the fixtures and the use of palatal mucosal grafts around the implants. Final dental prostheses were fixed 1 month later in seven patients, at this time. All flaps survived after surgery, and no implant failure was observed after a mean follow-up period of 25 months. Only one fixture was not used during the subsequent stage and was left as a sleeper. Fixed dental prostheses were used in five patients and removable overlay prostheses in the other two. Chewing function was recovered between 4 and 6 weeks after the start using the definitive dental prosthesis. In contrast to previous results, we conclude that excellent results can be achieved when this combined procedure is used in carefully selected patients. In addition, it is confirmed that the fibula osteoseptocutaneous flap is a versatile, reliable composite tissue that facilitates primary placement of osseointegrated dental implants during mandible reconstruction, thus allowing full oral rehabilitation in a shorter period of time.     

Advances in osseointegrated implants for dental and facial rehabilitation following major head and neck surgery

Osseointegrated implants can be used to facilitate retention stability and support for facial and intraoral prostheses used to restore head and neck defects. Preliminary studies indicate that in nonirradiated maxillectomy patients the success rates are about 75%. In the reconstructed mandible the results appear to be more favorable--over 90% for implants placed in free nonvascularized bone grafts and over 90% for free revascularized bone grafts. Similar high success rates have been observed for most sites used to support facial prostheses. Success rates for auricular sites exceed 95% and for floor of nose sites success rates exceed 90%. Success rates have been lower (77%) for implants placed in the frontal bone for retention of orbital prostheses. Success rates for irradiated bone sites have been lower and range from 60.4% in the maxilla to 68.6% in facial bone sites. Of greater concern is that most implants placed in irradiated sites are beginning to show signs of impending failure.     

Ten-year results for Br?nemark implants immediately loaded with fixed prostheses at implant placement

This investigation was initiated to develop a method to provide patients with a fixed provisional prosthesis placed at the time of implant placement. Sixty-three standard 3.75-mm Nobel Biocare implants of varying lengths were placed into mandibular sites in 10 patients and followed for up to 10 years. Twenty-eight implants were immediately loaded at implant placement, providing support for fixed provisional prostheses, while 35 adjacent implants were allowed to heal submerged and stress-free. Following a 3-month healing period, the submerged implants were exposed and definitive reconstruction was accomplished. All 10 prostheses supported by 28 implants placed into immediate function at the time of implant placement were successful during the 3-month healing period. Of these 28 implants placed into immediate function, 4 ultimately failed. Of the 35 submerged implants, all are osseointegrated and in function to date. Life-table analysis demonstrates an overall 10-year survival rate of 93.4% for all implants. The 10-year life-table analysis of survival is 84.7% for immediately loaded implants and 100% for submerged implants. Statistical analysis of the submerged versus immediately loaded implants demonstrates failure rates for immediately loaded implants to be significantly higher (P = .022 by the log rank test). These data demonstrate that although mandibular implants can be successfully placed into immediate function in the short term to support fixed provisional prostheses, long-term prognosis is guarded for those implants placed into immediate function distal to the incisor region.     

The influence of splinting procedures on the periodontal and peri-implant tissue damping characteristics. A longitudinal study with the Periotest device

The aim of the present study was to evaluate the capability of the Periotest device in detecting and monitoring functional changes in the periodontal as well as in the pari-implant damping characteristics. In the first part of this study, 107 teeth were splinted by means of 40 full acrylic fixed prostheses (AFP) and another 37 teeth were splinted by means of 14 ceramometallic fixed prostheses (C-MFP). The Periotest measurements of individual teeth were done the day the fixed prostheses were cemented temporary (PTV 1), and again after a mean observation period of 27.4 days (PTV 2). In the 2nd part, 78 osseointegrated two-stage implants were splinted by means of 23 full acrylic fixed prosthesis (AFP) and other 18 implants were left without it. Using the same abutment length, Periotest measurements were performed, at abutment connections and before installation of the final prosthesis. In a 3rd part, using both implants and teeth as abutments, 29 osseointegrated implants were connected with 25 abutment teeth by means of 7 AFP. The measurements were performed at the beginning of the prosthetic treatment and 2, 4 and 6 weeks later. After splinting teeth by means of AFP for the observation period, no statistically significant reduction in PTVs was found. When on the other hand, a C-MFP was used, PTV 2 showed a significant reduction. The PTVs at abutment connection went down after a period of time, during which some implants were interconnected by means of an AFP and others were not.(ABSTRACT TRUNCATED AT 250 WORDS)     

Aesthetic considerations for maxillary obturators retained by implants

Maxillary obturators are prostheses used to replace maxillary tissues, missing congenitally or removed by trauma or tumor ablative surgery. These prostheses are used to restore function (speech, swallowing, and mastication) and aesthetics. A considerable number of edentulous patients have difficulty in retaining this type of prosthesis. Utilization of osseointegrated dental implants is a significant adjunct in treating these cases, but it must be undertaken with careful planning to ensure predictable aesthetic results. The learning objective of this article is to discuss the technique of designing aesthetic maxillary prostheses supported by osseointegrated dental implants. The discussion includes indications and contraindications, and a postcarcinoma surgery case is used to illustrate the clinical procedure.     

Are mu-opioid receptors involved in the control of endothelin-1 release from the pituitary gland in normal and dehydrated rats?

A stereognostic ability test was performed in 60 patients. Forty patients were rehabilitated by means of osseointegrated implants. One group consisted of 20 patients with fixed prostheses on implants in both the upper and lower jaws. The other 20 patients had a maxillary denture while in the mandible an overdenture was retained by means of two implants connected by a bar. They were compared to a group of 20 subjects (controls) with a non-restored natural dentition. For the stereognostic ability test, subjects had to recognise ten different test pieces by manipulating them with two antagonistic incisor teeth, avoiding any contact with other oral structures. Both response time and percentage accuracy of recognition were evaluated. The present findings indicated that subjects with an overdenture on implants did not score significantly different from those with an implant-supported fixed prosthesis. In contrast, subjects with teeth had a significantly better stereognostic ability. The percentage of correct responses was 52% for overdentures, 56% for fixed prostheses on implants and 75% for natural dentitions. From these results, it could be concluded that the stereognostic ability is impaired in subjects rehabilitated with osseointegrated implants by about one-third to one-quarter compared to subjects with natural teeth.     

Primary diffusely infiltrative adenocarcinoma of the colon and rectum

In this study, patient opinion on oral rehabilitation by means of Br?nemark implants was investigated. All patients were referred to a periodontal clinic for implant installation and treated by one and the same operator. Prosthetic restorations were performed by dentists, who had no previous experience with prostheses on implants, but had completed a postgraduate training course. Patient opinion was obtained through questionnaires, pertaining to satisfaction and oral function. A comparison was made between pre-implant situation, short-term (< 4 months) and long-term functioning (3 years) with the implant-restorative rehabilitation. In total, 61 patients participated in the study; 23 received a full lower arch bridge and 18 a full upper arch bridge, while 20 patients got partial bridges. Of 298 installed implants, 7 failed at abutment connection (2.3%) and 1 during the 3-year follow-up interval (0.3%). The study results indicated that a great majority of patients were very satisfied with the treatment. Comfort with eating, aesthetics, phonetics and overall satisfaction improved significantly and nearly all patients said that they would undergo the treatment again or recommend it to others. Patients experienced their implants as "natural" teeth. The conclusion is that rehabilitation ad modum Br?nemark, even in the hands of non-specialized dentists, can be of high quality, improving oral function and satisfying the needs and demands of patients.     

Problems associated with the atrophic mandible

A range of treatment options has been presented regarding the use of dental implants to rehabilitate patients who otherwise have compromised function using conventional tissue-borne prostheses. This patient population offers significant challenges to both the surgeon and the prosthodontist. Generally speaking, IODs retained on two or more endosteal osseointegrated implants; transosteal, subperiosteal, ramus frame implant-supported and implant-retained prostheses, and a totally implant-supported design offer options to treat the severely atrophic mandible. When bone support or volume is so lacking that augmentation procedures are required, bone grafting can be considered as a treatment option. The state-of-the-art of implant treatment for the atrophic mandible offers to the dental professional and patient a variety of options. Thus far, it is too early to make specific recommendations as to which treatment offers the best option for each patient. It is fair to say that the ISP remains the gold standard against which other treatments can be compared.     

Outcome assessment of implant-supported prostheses

STATEMENT OF PROBLEM: From the dental professional's standpoint, implant rehabilitation offers dramatically improved treatment alternatives to orally disabled patients. However, what a patient perceives as important to their function and satisfaction with their prostheses may be quite different from what the dentist believes are significant health-related improvements. PURPOSE: To resolve this problem, a series of investigations were designed to measure satisfaction and performance in groups of patients who wore various types of prostheses supported by endosseous titanium implants. MATERIAL AND METHODS: Methods are described for assessing treatment efficacy and population needs, including measures of perceived levels of disability, health-related quality of life, and functional capacity. RESULTS: The findings highlight patient factors that have not been considered before and appear to contribute to the success of prosthetic rehabilitation for the edentulous patient. CONCLUSION: Patient-centered approaches to the assessment of treatment efficacy are highly relevant to today's prosthodontists, whose goals are the improvement of function and quality of life for their patients.     

Patient satisfaction with dentures made by dentists and denturologists

BACKGROUND: Within Quebec and elsewhere in Canada, patients requiring removable prostheses consult either dentists or denturologists. In this article, we describe the socioeconomic characteristics of 410 edentulous individuals seeking replacement of their dentures, and compare the levels of satisfaction experienced by the patient groups provided with conventional dentures by dentists and by denturologists. METHODS: All subjects responded to announcements seeking participants in a clinical trial. The announcements indicated that all participants would receive new prostheses. Data were collected via telephone interviews. Sociodemographic variables included sex, age, education level and family income. Subjects were asked to evaluate their present maxillary and mandibular prostheses for general satisfaction, stability, comfort, ability to chew, ability to clean and appearance. Age, cost and the provider (dentist or denturologist) of the original prostheses were also recorded, and responses were then compared between the groups of subjects treated by dentists (N = 91) and denturologists (N = 319). RESULTS: There were no significant differences in the sociodemographic characteristics of the two groups, except for a small difference in mean age (two years). Both groups had paid approximately the same amount for their complete prostheses. As expected, most individuals were satisfied with their maxillary prostheses, but dissatisfied with their mandibular prostheses. Significantly more subjects in the denturologist treatment group than the dentist treatment group gave their mandibular prostheses a poor rating for general satisfaction (p = 0.003), comfort (p = 0.04) and stability (p = 0.016). CONCLUSIONS: These results suggest that the edentulous patients treated by dentists and denturologists share similar sociodemographic characteristics, and pay a similar cost for treatment. However, those treated by denturologists seem to be more dissatisfied with their mandibular prostheses than those treated by dentists.     

An interactive, parallel, three-dimensional fast Fourier transform convolution dose calculation using a supercomputer

After cancer treatment in the head and neck area, mastication and speech are often affected. Some of the problems encountered can be solved by adequate dental rehabilitation. However, dental rehabilitation is often compromised for various reasons. The change in anatomy due to surgery often results in lack of denture-bearing mucosa. The effects of radiotherapy on the salivary glands and the mucosa result in dry oral tissue and diminished retention of removable dentures. Osseointegrated oral implants can help to solve these problems. Although implant treatment for patients with cancer of the head and neck is covered by the Dutch national health insurance, and there is therefore no financial obstacle, implants have not, so far, been widely used with these patients. In order to establish the possible reasons for this, an analysis was performed. Retrospective data on 95 consecutive patients were collected from records. The indication for the use of oral osseointegrated implants was reviewed. Analysis of the data showed that 45% did not need specific prosthetic rehabilitation. An indication for the use of osseointegrated implants was found in 25% of the patients. For various reasons, only 3% actually received implants. In striving to completely rehabilitate a cancer patient, the possible use of osseointegrated oral implants should be evaluated before the initial oncological treatment begins. The insertion of implants during the initial surgical procedure should be considered more often, with a view to reducing the number of surgical procedures.     

The use of the Periotest value as the initial success criteria of an implant: 8-year report

Osseointegration is a histometric process that occurs gradually over a period of time. The load that an implant is able to bear depends upon, among other parameters, the quality of the bone-implant contact. For 8 years the damping capacity of 1,182 Br?nemark implants inserted consecutively in 315 patients was measured using the Periotest method. The following clinical observations were made: (1) a relationship was found between implants with a specific Periotest value range that, at the moment of the transepithelial connection, were considered to be clinically stable, asymptomatic, and whose radiograph image was not radiolucent; (2) a relationship was found between clinically nonintegrated implants with a different Periotest value range; (3) variations in the Periotest value were related to the type of bone in which the implant was placed; (4) a small percentage of borderline implants with a Periotest value between the osseointegrated and the nonosseointegrated Periotest values was detected; (5) the percentage of secondary failures was related to an initial Periotest value corresponding to a borderline implant; (6) the healing time of each implant was individualized in accordance with the successively obtained Periotest value; (7) the load and the design of the prosthesis were individualized; (8) early detection of failing implants before fabrication of prostheses is possible; (9) communication was improved between the surgeon and the prosthodontist; and (10) variations in Periotest value were related to bone remodeling. The sensitivity of the principal clinical test in evaluating osseointegration is discussed regarding the moment of its application. The use of Periotest values as an initial success criteria of an implant is proposed.     

Fabrication of a fixed partial denture in the Class II partial edentulous mandible using the UCLA abutment: a clinical report

Several methods are currently available to restore the partially edentulous patient with osseointegrated implants. The UCLA abutment eliminates the unesthetic, traditional transmucosal abutment and can provide esthetic crowns, fixed prostheses, and subgingival porcelain margins without the need for excessive instrumentation and components. A clinical report for the fabrication of a direct, implant-borne fixed prosthesis using the UCLA abutment is presented.     

Rupture of silicone gel filled testicular prosthesis: causes, diagnostic modalities and treatment of a rare event

PURPOSE: Rupture of the envelope of silicone gel filled testicular prostheses is rare and alleged to be unlikely without intraoperative needle puncture. We observed that it may be caused by chronic intermittent trauma or a single acute increase of pressure, and report diagnostic and therapeutic modalities. MATERIALS AND METHODS: Four cases treated by us during the last 10 years are presented. One patient had testicular implants for Klinefelter's syndrome, whereas the other 3 had been treated for female-to-male transsexualism. Diagnosis was confirmed by ultrasonography and magnetic resonance imaging. The fibrous capsule surrounding the ruptured prosthesis was left intact to allow en bloc surgical extirpation. Histological evaluation of the resected specimen was performed. RESULTS: Rupture of silicone gel filled testicular implants may be caused by acute or chronic pressure without intraoperative needle puncture. CONCLUSIONS: Magnetic resonance imaging offers superior diagnostic accuracy and should be regarded the gold standard in the evaluation of implant rupture. Ultrasonography is an acceptable alternative. In cases when gross symptoms of scrotal inflammation are lacking replacement of implants is facilitated by the fibrous capsule that forms around any prosthesis. Transcapsular migration of silicone particles was observed even when the fibrous capsule was intact.     

A within-subject comparison of mandibular long-bar and hybrid implant-supported prostheses: psychometric evaluation and patient preference

Although it has been shown that patients are more satisfied with prostheses supported by implants than with conventional dentures, there have been few direct comparisons of the various designs of implant-supported prostheses. This within-subject crossover clinical trial was designed to compare two forms of removable prostheses which are frequently prescribed for the edentulous mandible: a long-bar overdenture supported by 4 implants and a two-implant hybrid overdenture. Sixteen completely edentulous subjects were given a new maxillary conventional denture: Ten of them received the mandibular long-bar prosthesis first and six the hybrid. After a two-month adaptation period, psychometric measures of various aspects of the prostheses and physiological tests of masticatory efficiency were carried out over three weeks. The mandibular prostheses were then changed and the procedures repeated. At the end of the study, subjects were asked to choose the mandibular prosthesis that they wished to keep, and final psychometric measures were taken. In this paper, the results of the psychometric assessment and patient preference are presented. Subjects assessed factors such as general satisfaction, quality of life, stability, retention, comfort, esthetics, ease of cleaning, speaking, and chewing, and how well-chewed foods were before being swallowed. Most of the factors except ease of cleaning and speaking were rated significantly better with long-bar overdentures than with hybrid ones. These results are consistent with the fact that all subjects chose long-bar overdentures, reporting stability, ease of chewing, and comfort as the most important factors influencing their choice. These results suggest that, although subjects assign high ratings for most factors to hybrid overdentures, they find long-bar overdentures to be significantly more stable, comfortable, and easier for chewing.     

Altered patterns of DNA methylation on chromosomes from leukemia cell lines: identification of 5-methylcytosines by indirect immunodetection

The feasibility of implant treatment in patients after oral ablative tumor surgery has not yet been investigated with consideration of the requisite high periodontal standards. A report on this topic has to deal not only with implant survival but also with implant health, bone response, soft tissue health, failure pattern, time of failure, and ease of restoration. For the assessment of an implant system, an overview must be accomplished that takes into account the different restorations used and their interaction with the implant system that was used. This study presents the Bone-Lock implant system (Howmedica Leibinger GmbH, Freiburg, Germany) in a retrospective investigation after 5 years of follow-up with special emphasis on the prosthetic restorations used following resection of oral malignancies. From early in 1990 through June 1996, we inserted 210 dental endosteal Bone-Lock implants (58 patients) after oral tumor resectioning. Included in the study were 45 patients with 162 implants and prosthetic restorations that had been loaded for 1 year (dentures retained by telescopic or bar-clip or ball attachments, implant-supported prostheses, tooth-to-implant connected bridges). Regular follow-up consisted of evaluation of the Plaque Index (Silness and L?e) and of the Sulcus Bleeding Index (L?e), measurements of pocket probing depth, implant mobility (by means of the Periotest method), bone resorption (according to X-ray findings), and a questionnaire that registered patient satisfaction. The results were evaluated for each restoration and were compared with baseline standards. The overall 5-year survival rate was 83.2%. For implants that had been in place for over 365 days, the survival rate was 93%. The investigation showed that after resection of oral malignancies, patients could be treated with dental implants and superstructures with long-term efficacy similar to that found in healthy subjects considering internationally accepted standards. Implant treatment in tumor patients appeared to offer the most positive periodontic results when use of bar-clip or telescope-retained overdentures was involved. The patient satisfaction level with the described prosthodontic treatment was satisfactory.     

Ligature-induced marginal inflammation around osseointegrated implants and ankylosed teeth: stereologic and histologic observations in cynomolgus monkeys (Macaca fascicularis)

The aim of the investigation was to provide quantitative and qualitative histologic data on marginal inflammation around osseointegrated implants. The significance of the lack of a periodontal ligament in the initial breakdown phase of supporting tissues in implants was examined by comparing stereologic and histologic manifestations of ligature-induced marginal inflammation around osseointegrated implants with those around ankylosed and normal control teeth in 8 cynomolgus monkeys (Macaca fascicularis). Clinical and radiographic findings have been reported elsewhere. The marginal connective tissue around ligated implants was infiltrated by a significantly increased total number of lymphocytes, plasma cells, and neutrophils compared to non-ligated implants and teeth. The total number of lymphocytes around ligated implants was significantly higher than around ligated ankylosed and normal control teeth. There were, however, no significant differences in the total number of plasma cells and neutrophils within the ligated group. Osteoclasts were exclusively observed around ligated implants and ankylosed teeth. Although variations in microbiota and susceptibility of different jaw positions to periodontal break-down may influence the results of the present study, the results seem to substantiate the theory that marginal inflammation around implants and ankylosed teeth may have more serious implications than does marginal inflammation around teeth with a periodontal ligament. Since presence of osteoclasts was not related to the absence of cervical cementum with inserting gingival fibers around ligated ankylosed teeth, the increased susceptibility of bone loss of implants is probably not caused by the absence of these tissue components. In contrast, the histologic observations seem to support that the increased susceptibility for bone loss around implants may be related to the absence of a periodontal ligament.     

Epinephrine in digital blocks: revisited

STATEMENT OF PROBLEM: Implant treatment in the United Kingdom has been provided mainly in specialist, regional dental hospitals. However, increasingly, general dentists are providing implant-supported prostheses in a private office setting. PURPOSE: This study investigated the nature, timing, and frequency of complications associated with single tooth implant therapy in a dental hospital and two dental offices. METHODS: The dental records of 58 patients provided with 76 implants during the period of 1989-95 were reviewed retrospectively. Fifty-three single tooth crowns on implants were placed by general dentists and 23 by specialists in the dental hospital. RESULTS: Implant survival rate was 96%. Twenty-eight guided bone regeneration procedures were required, including 13 unplanned ones. Prosthodontic complications included the need for recontouring of three crowns and the recementation of three crowns. Only two abutment screws required retightening. Peri-implant soft tissue inflammation occurred around six crowns and recession around two. CONCLUSION: The single tooth implant-supported crown appears to be an effective and durable restorative treatment with a relatively low prevalence of postoperative complications.     

Endosseous implants for prosthetic rehabilitation in bone grafted alveolar clefts

The authors report their experience in the surgical and prosthetic rehabilitation of three patients affected by sequelae of cleft lip and palate, with residual alveolar cleft and absence of maxillary anterior teeth. The patients were treated by means of late secondary bone grafting of the alveolar cleft, followed by the insertion of endosseous titanium plasma-sprayed implants (IMZ). After a further healing period (6-12 months) fixed dental prostheses were constructed. Preliminary results from this series have shown how dental prostheses supported by endosseous implants in grafted alveolar clefts are a very reliable possibility in dental rehabilitation of this malformation.     

A comparison of vascularized and nonvascularized bone grafts for reconstruction of mandibular continuity defects

PURPOSE: This study compared vascularized and nonvascularized bone grafts for the reconstruction of segmental defects of the mandible. PATIENTS AND METHODS: The results in 39 patients having vascularized bone grafts (38 fibulas and one iliac crest) and 29 patients having nonvascularized bone grafts (26 iliac crest [22 corticocancellous block grafts, four cancellous bone grafts in a tray] and three rib grafts) for segmental mandibular reconstruction were evaluated in terms of overall success rate, total number of surgeries performed, total blood loss, total number of hospital days, and total number of hours in the operating room. RESULTS: Of 39 vascularized bone grafts, two failed (95% success rate), whereas of 29 nonvascularized bone grafts, seven failed (76% success rate). Failure for the nonvascularized bone grafts was closely correlated to the length of the defect. Nonvascularized bone graft patients underwent an average of one more surgical procedure for total reconstruction than vascularized bone graft patients, including osseointegrated implants. However, vascularized bone graft patients spent a mean of over 14 additional days in the hospital for all of their reconstructive procedures and an additional 3 hours in the operating room as compared with nonvascularized bone graft patients. Blood loss was similar in both groups (1,100 mL). Only 20% to 24% of patients in each treatment group have completed reconstruction to include osseointegrated implants. CONCLUSIONS: The success rate for vascularized bone grafting is high and is the treatment of choice when primary reconstruction is required, when the patient has been previously irradiated, or when simultaneous replacement of soft tissue is required. Vascularized bone grafts are also the treatment of choice for mandibular replacements over 9 cm in length. Nonvascularized bone grafts create a better contour and bone volume for facial esthetics and subsequent implant insertion, and may be the treatment of choice for secondary reconstruction of defects less than 9 cm in length.