Influence of patient age on the success rate of dental implants supporting an overdenture in an edentulous mandible: a 3-year prospective study.

The aim of this study was to determine the influence of age on peri-implant tissues in patients treated with implant-supported overdentures in the mandible. A prospective study was carried out with 2 groups of healthy edentulous patients. The mean age of the younger group (n = 32) was 46 years (range 35 to 50 years); the mean age of the older group (n = 26) was 68 years (range 60 to 80 years). Two dental implants were placed in the interforaminal region of the mandible, and after a 3-month healing period, overdentures were fabricated. Clinical and radiographic parameters were evaluated immediately after completion of the prosthetic treatment, after 1 year, and after 3 years. The evaluated clinical parameters were implant loss, Plaque Index, Gingival Index, Bleeding Index, and probing depth. Radiographic evaluation was performed using a standardized long-cone technique with a direction device. Statistical analysis was carried out with SPSS software. One implant in the older group was lost during the healing period. After 3 years, the mean scores for Plaque Index, Gingival Index, and Bleeding Index were between 0 and 1 for both groups (out of possible scores of 0 to 3), and the mean probing depth was 3 mm in both groups. The mean bone loss after 3 years was 1.2 mm in the younger group and 0.8 mm in the older group, but this difference was not significant. It was concluded from this study population that the clinical performance of implant-supported overdentures in the mandible is equally successful in younger and older patients.

A comparison of labial and crestal incisions for the 1-stage placement of IMZ implants: a pilot study.

PURPOSE: The aim of this study was to compare the crestal incision with the labial flap design when inserting a 2-stage implant system in a nonsubmerged manner. PATIENTS AND METHODS: Ten consecutive edentulous patients with a severely resorbed mandible (Cawood Class V to VI) that resulted in reduced stability and insufficient retention of the lower denture were included. In all patients, 2 IMZ implants were inserted in a 1-stage procedure in the mandibular canine regions as part of an implant overdenture treatment. In 5 patients, the labial flap approach was used, and a crestal incision approach was used in the other 5 patients. Standardized evaluations were performed at 2, 6, and 12 weeks after implant placement and 12 months after placement of the new prosthesis. RESULTS: In the first postoperative weeks, more hyperplasia occurred around the implants inserted by the crestal incision than the labial flap. However, after 1 year of function, no striking differences between the 2 groups were present with regard to the clinical and radiographic parameters. CONCLUSIONS: From this pilot study, it was concluded that both the crestal incision and the labial flap approach are reliable procedures for insertion of IMZ implants in a 1-stage procedure. However, because of the smaller risk of soft tissue overgrowth, there is a preference for the labial flap approach.

Etiology and management of mandibular fractures associated with endosteal implants in the atrophic mandible.

Mandibular fractures can occur with the insertion of endosseous implants. Four patients whose mandibles were fractured with the removal or insertion of mandibular endosseous implants are described. Three of the patients required an autogenous bone graft to repair the fracture, and 1 patient was managed with a reconstruction plate. Strategies for prevention and treatment of this uncommon complication are discussed.

The oblique radiographic technique for bone height measurements on edentulous mandibles: a preclinical study and an introduction to the clinical use.

OBJECTIVE: The aim of this study was to quantify the effect of mandibular angulation, position, and shape of the edentulous mandible on the distortion of its image on lateral oblique radiographs in a preclinical study. Suggestions for the clinical use of this technique are made. STUDY DESIGN: Five edentulous dry mandibles were used, varying in size from small to wide and equipped with metal bars in and on top of the mandible. The mandibles were radiographed at 9 different positions by tilting the mandible around the intercondylar axis and by using the oblique projection technique in a cephalostat. RESULTS: The length of the images of the metal bars varied significantly when we tilted the mandibles from 20 degrees to -20 degrees. As a result of the effects of magnification and distortion, the image size varied from between 0.96% and 1.06% of the real size. Neither the size of the mandible nor the position of the bars was related to the degree of magnification. CONCLUSION: The oblique projection technique has limited geometric errors in depicting the edentulous mandible. For evaluative bone height measurements in patients with extremely resorbed mandibles treated with dental implants, it is a promising technique if the patient (specifically the mandible) can be positioned reproducibly in the apparatus.

Horizontal osteotomy for reconstruction of the narrow edentulous mandible.

The aim of this retrospective study was to evaluate the applicability of a horizontal osteotomy procedure for reconstruction of a narrow edentulous mandible in order to enable insertion of implants. In 7 edentulous patients a narrow inferior alveolar ridge was reconstructed with autogenous bone grafts harvested by a horizontal osteotomy procedure (mean width of the top of the alveolar crest before grafting 1.3 +/- 0.3 mm, after grafting 5.6 +/- 0.6 mm). Insertion of endosseous implants (10 Brånemark implants, 8 ITI Bonefit implants) was performed 3 months after the grafting procedure. Implant supported overdentures were fabricated 3 months after implantation. At regular time intervals a standardized clinical and a radiographic evaluation was performed. All grafted sites showed sufficient bone volume for insertion of the implants at the moment of implantation. At time of evaluation (mean 37 +/- 14.6 months, range 14-68 months) all implants and overdentures functioned well. None of the patients showed a disturbed sensitivity of the lip or chin region. It is concluded that reconstruction of a narrow edentulous mandible with autogenous bone grafts harvested by an intraoral horizontal osteotomy was shown to be a reliable preimplantology procedure with potential applicability in this group of patients.

Morbidity and complications of bone grafting of the floor of the maxillary sinus for the placement of endosseous implants.

Placement of endosseous implants in the atrophic maxilla is often limited because of a lack of supporting bone. A technique to augment the floor of the maxillary sinus with autogenous bone graft seems to be a new reliable treatment modality. The morbidity and complication rate of augmentation of the maxillary sinus floor was studied in 75 patients. The sinus floor was augmented with iliac crest (n = 65, 128 sinuses, 276 implants), mandibular symphysis (n = 8, ten sinuses, 21 implants), or maxillary tuberosity grafts (n = 2, two sinuses, two implants). The width of the alveolar crest had to be reconstructed in 52 patients, while in the other 23 patients augmentation and implantation were performed simultaneously. Perforation of the sinus membrane occurred in 45 patients, but this did not predispose them to the development of sinusitis. Loss of bone particles and sequesters were observed in one (diabetic) patient only, in whom a mucosal dehiscence occurred. A second augmentation procedure was successful. Symptoms of transient sinusitis were observed in two of the seven patients with a predisposition for sinusitis. These symptoms were successfully treated with decongestants and antibiotics. One patient developed a purulent sinusitis which resolved after a nasal amrostomy. The bone volume was sufficient for insertion implants in all patients. Twenty of 299 patients (6.7%) in whom Brånemark implants had been inserted were lost to follow-up (mean, 32 months); no sinus pathology was observed. The patients received implant-supported overdentures (58 patients) or fixed bridges (17 patients) and experienced no complaints with regard to the grafts or implants. We conclude that the morbidity and complication rate of bone grafting of the floor of the maxillary sinus floor with autogenous bone is low.

Bone grafting of cleft lip and palate patients for placement of endosseous implants.

OBJECTIVE: Fixation of a prosthesis or single tooth replacement using osseointegrated implants has the potential to overcome functional and psychological inconveniences that many patients experience from such appliances. However, the dimensions of the recipient site are relatively often inadequate for implant placement. This study assessed grafting of this site with autogenous bone as a solution for the latter problem. METHODS: Ten cleft lip and palate patients had bone grafts; six had iliac crest grafts to the maxillary sinus floor (31 implants), and four had chin bone grafts to the local defect in the anterior maxilla (six implants). Implants were inserted during the grafting procedure (one patient) or after 3 months (nine patients). RESULTS: No inflammation of the bone grafts or the maxillary sinus occurred. One implant was lost during the healing phase. Four single tooth restorations, one fixed bridge, and five implant-supported overdentures were made. During the follow-up, which was 47 months (range, 28 to 65 months) in the anterior maxilla group and 56 months (range, 28 to 68 months) in the posterior maxilla group, no loss of implants was observed, and all prosthetic appliances functioned well. CONCLUSIONS: It is concluded that bone grafting followed by placement of dental implants can serve as a reliable alternative for conventional prosthetic rehabilitation of cleft patients.

[Local bone augmentations for the use of implants]. / Lokale botaugmentaties ten dienste van implantaten.

Placement of endosseous implants is often restricted because of lack of supporting bone, limiting placement of implants of adequate length in a prosthodontically optimal position. Several surgical procedures have been described to create sufficient volume of bone for placement of implants. In this paper, various techniques are described for harvesting intraoral bone grafts for augmentation of a localized defect of the alveolar ridge.

Mandibular overdentures supported by two or four endosteal implants. A prospective, comparative study.

The aim of this prospective study was to evaluate the effect of the number of implants supporting a mandibular overdenture on the condition of the peri-implant tissues. Sixty edentulous patients (Cawood class V VI) participated in this study. After randomization, thirty patients were treated with an overdenture supported by two IMZ implants (group A) and thirty patients with an overdenture on four IMZ implants (group B). The implants were inserted in the anterior region of the mandible. After three months overdentures were constructed, supported by round bar and clip attachments. A standardized clinical and radiographic evaluation was performed 0, 6 and 12 months after insertion of the denture. One implant was lost (group A) during the healing period. There were no significant differences with regard to any of the studied clinical or radiographic parameters of the peri-implant tissues, neither were significant differences found between the lateral and central implants in group B. None of the patients reported a sensory change in lip or chin region. From this study it is concluded that there seems to be no need to insert more than two endosteal implants to support an overdenture, however, long-term prospective studies are needed to support this notion.

Radiographic assessment of changes in marginal bone around endosseous implants supporting mandibular overdentures.

OBJECTIVES: To evaluate the reliability of a new method for quantification of radiographic changes in the marginal bone around implants. METHODS: Three groups of seven patients treated with an overdenture supported by two endosseous implants (Brnemark, n = 7 patients; IMZ, n = 7 patients; ITI Bonefit, n = 7 patients) were selected. Six weeks after loading the implants, radiographs were obtained using the long cone technique and an aiming device, scanned and digitized. Two observers measured the height and area of the peri-implant bone defects twice. The difference between measurements was statistically analysed using paired t-tests. RESULTS: There were small differences in interobserver error for the Brnemark implant system (P < 0.05), but no significant differences for the IMZ and ITI Bonefit. There were no significant difference in intraobserver error with any of the three implant systems (P > 0.05). CONCLUSIONS: The newly developed technique by measuring the area of the defect overcomes some drawbacks of existing techniques for quantification of peri-implant bone loss in the mandible.

Reconstruction of the extremely resorbed mandible with interposed bone grafts and placement of endosseous implants. A preliminary report on outcome of treatment and patients' satisfaction.

During recent decades many surgical techniques have been developed to enlarge the denture-bearing area of the mandible. Most of these techniques improved retention and stability of the lower dentures only temporarily. Since the advent of endosseous implants to stabilize overdentures, combinations of augmentation procedures and placement of endosseous implants have been introduced to restore the severely resorbed mandible. In this study we describe the preliminary results of such a combined approach using sandwich osteotomy with an autogenous bone graft (iliac crest) followed by placement of four endosseous implants in the interforaminal region in 10 women. After a mean follow-up period of 31 months (range 19-57) several variables were measured including condition of the peri-implant tissues, radiographic bone changes and patient satisfaction. The first results indicate that the technique described offers a solid base for implant-stabilized overdentures: no implants were lost, the peri-implant tissues were in good condition, bone loss was limited, and patients were satisfied. Future studies will evaluate the permanence of these results.

Dentin dysplasia type I: five cases within one family.

Five cases of dentin dysplasia type I within one family are described. Clinically and radiologically, such patients are characterized by a delayed eruption pattern, opacity of the incisional margins, hypermobility of the teeth, short and defective roots, and obliterated pulp chambers. A conservative attitude toward the treatment of common conditions in dentin dysplasia type I favors the preservation of a vulnerable dentition.

Treatment concept for mandibular overdentures supported by endosseous implants: a literature review.

Edentulous patients with a severely resorbed mandible often experience problems with their dentures. Treatment concepts involving two to four implants for the support of an overdenture have been proposed. The aim of this study was to develop a treatment concept for mandibular overdentures supported by endosseous implants based on a review of the literature. It is proposed that two implants supporting a mandibular overdenture (bar construction) are sufficient for most applications. Four implants were indicated in situations involving a dentulous maxilla, a narrow mandibular arch, extreme resorption of the mandible (bone height greater than 12 mm), and mandibular soreness and pain.

Overdentures stabilised by two IMZ implants in the lower jaw--a 5-8 year retrospective study.

Clinical and radiographical parameters were assessed in forty patients with overdentures stabilised by two IMZ implants connected by a bar in the lower jaw in a 5-8 years retrospective study. Results indicated that most patients had healthy peri-implant tissues, the mean pocket probing depth was 3.1 mm and the median periotest value was -4. Three implants were removed after the healing period and replaced by three new implants. One implant was lost after six years. One implant was mobile on palpation. None of the patients showed objective signs of dysaesthesia in the lower lip or chin. The peri-implant bone level of most implants had remained stable after one year of service. The overall success rate was 94% (Albrektsson et al.) and it is therefore concluded that two IMZ implants, connected with a bar in the lower jaw, provide a stable base for long-term support of a mandibular overdenture.

[Dental implants: a better anchor for dentures]. / Tandheelkundige implantaten: een beter houvast van een kunstgebit.

Loss of teeth results in resorption of the jaws. As a consequence the denture bearing area progressively reduces, eventually causing loss of retention and stability of the conventional denture. In three patients, two women aged 36 and 37 and a man aged 46, suffering from severe problems with their conventional dentures endosteal implants were inserted in the jawbone. After the healing period the dentist fabricated an implant-retained overdenture. The patients were very satisfied with the final result. Endosteal implants are, especially in the mandible, a reliable treatment modality for a stable implant-retained denture in case of patients suffering from retention problems with their conventional dentures.

[Templates as an aid in implantology]. / De sjabloon als hulpmiddel in de implantologie.

The number, position and angulation of implants are of major importance in loading of implants and surrounding bone and in esthetics. Especially in single tooth and partially edentulous cases correct positioning of implants takes a great deal of care. A template is a device that helps to achieve the proper amount of bone and the correct position and angulation of implants. The design and fabrication of radiographic templates, diagnostic templates and surgical templates are described, both in general and specifically for overdentures and non-removable implant-supported restorations.

Mandibular overdentures supported by two Brånemark, IMZ or ITI implants. A prospective comparative preliminary study: one-year results.

The aim of this prospective comparative study was to evaluate the condition of the peri-implant tissues of three different implant systems supporting a mandibular overdenture. Ninety edentulous patients (Cawood class V-VI) participated in this study. After randomization, 30 patients were treated with 2 Brånemark implants, 30 patients with 2 IMZ implants and 30 patients with 2 ITI implants. The implants were inserted in the canine region of the mandible. After 3 months overdentures were fabricated supported by a round bar and clip attachment. A standardized clinical and radiographic evaluation was performed 0,6 and 12 months after insertion of the denture. The intraoral radiographs were made, using the long-cone technique with an aiming device. Two implants were lost (1 Brånemark, 1 IMZ) during the healing period. None of the patients showed any sensory change in lip or chin region. The pocket depth in the Brånemark group decreased significantly whereas the mucosa recession increased significantly in both the Brånemark as well as in the IMZ group. After 12 months, there was significantly less bone loss in the ITI group. From our study it was concluded that 2 (Brånemark, IMZ or ITI) implants placed in the interforaminal region connected with a bar supply a proper base for the support of a mandibular overdenture in the (Cawood V-VI) edentulous patient. The ITI implant appears to be the implant of choice for mandibular overdenture therapy, because only one operation is required for a comparable result.

Bone height measurements on panoramic radiographs: the effect of shape and position of edentulous mandibles.

OBJECTIVE: The aim of this study was to quantify the effect of mandibular angulation, position, and shape of an edentulous mandible on the distortion of its image in panoramic radiographs. STUDY DESIGN: Five edentulous dry mandibles varying in size from small to wide and equipped with metal bars in and on top of the mandible were used. The mandibles were radiographed at nine different positions by tilting the mandible posteriorly around a transversal axis, using an orthopantomograph. RESULTS: The length of the images of the bars on top of the mandible increased significantly by tilting the mandibles from +20 degrees to -20 degrees. The magnification factor of the images of the intrabony bars in the mandible was the largest at 0 degrees and decreased significantly by both decreasing or increasing the inclination. The size of the mandible was not related to the magnification factor. CONCLUSION: For both diagnostic and evaluation purposes of the edentulous mandible, the panoramic radiograph is not a reliable radiographic technique unless meticulous precautions are taken for reproducible positioning of the patient in the apparatus.

[Augmentation of the maxillary sinus floor and alveolar ridge for placement of endosseous implants in the edentulous maxilla]. / Sinusbodemverhoging en kaakverbreding ten behoeve van implantaten in de edentate bovenkaak.

Placement of endosseous implants in the atrophic maxilla is often restricted because of lack of supporting bone limiting placement of implants of adequate length in a prosthodontically optimal position. There are several surgical procedures to create sufficient volume of bone for the placement of implants. In this paper, a technique is described for augmentation of the maxillary sinus floor and simultaneous widening of the alveolar crest with autogenous bone.