Dental implant placement by predoctoral dental students: a pilot program.

Dental implant education is increasingly becoming part of predoctoral dental curricula. New York University College of Dentistry has developed a pilot dental implant program that trains students in implant restorations for single-tooth restorations and mandibular overdentures. Fourth-year students have the option of applying for an implant honors program, which can include surgically placing posterior implants. Eight students were selected for the implant honors program for the 2010-11 academic year. Seven of the eight students fulfilled the didactic and simulation requirements, performing forty-seven surgeries and placing fifty-two implants. Surgical protocol events were recorded: three implants did not achieve 35 Ncm torque at placement, and ten implants required a change in direction following the initial 8 mm pilot drill. All direction changes were successfully performed and resulted in implant placements. This pilot program suggests that predoctoral dental students can be trained to successfully place posterior implants, which are becoming the standard of care.

Survival rate of one-piece dental implants placed with a flapless or flap protocol--a randomized, controlled study: 12-month results.

The purpose of this randomized controlled clinical study was to compare the survival of a one-piece anodically oxidized surface implant when placed with a flapless or flap protocol. Bone loss measurements on radiographs and changes in clinical probing depths 1 year post-definitive restoration placement were recorded and compared. Fifty-two of 60 patients (implants) remained in the study at the 1-year follow-up. At the time of final evaluation, no implant was lost in either group. At the time of placement of the definitive restoration, there was a mean mesial and distal bone gain in both groups compared to bone levels present at the time of implant insertion. There were no significant changes in bone levels between placement of the definitive restoration and those recorded 12 months later, and no significant differences in bone levels between the flap or flapless group at 6 or 12 months were noted. No significant differences were seen either in pocket depth or change in pocket depth at 6 and 12 months in the flapless and flap groups. It was therefore concluded that one-piece anodically oxidized surface implants, 1 year post-definitive restoration insertion, had high survival rates (100%) and stable marginal bone and probing depth levels whether a flapless or flap protocol was used for implant insertion.

A restoratively driven ridge categorization, as determined by incorporating ideal restorative positions on radiographic templates utilizing computed tomography scan analysis.

BACKGROUND: The introduction of implants into the field of dentistry has revolutionized the way we evaluate edentulous ridges. In an attempt to evaluate the deficient edentulous ridge, numerous classification systems have been proposed. Each of these classification systems implements a different approach for evaluating and planning treatment for the ridge deficiency. PURPOSE: The purpose of the present investigation was to propose a restoratively driven ridge categorization (RDRC) for horizontal ridge deformities based on an ideal implant position as determined through implant simulation, utilizing computed tomography (CT) scan images. MATERIALS AND METHODS: Radiographic templates were developed to capture the ideal restorative tooth position. Measurements were performed using CT scan software in a cross-sectional view and by virtual placement of a parallel-sided implant with a 3.25-mm diameter. RESULTS: Edentulous ridges were divided into five groupings: Group I, simulated implants with at least 2 mm of facial bone, accounted for 19.4% of ridges; Group II, simulated implant completely surrounded by bone, with less than 2 mm of facial plate thickness, accounted for 10.4% of ridges; Group III, wherein dehiscences are detected but no fenestrations are present, accounted for 33.3% of ridges; Group IV, wherein fenestrations are detected but no dehiscence is present, accounted for 6.3% of ridges; and Group V, wherein both dehiscences and fenestrations are present, accounted for 30.6% of ridges. CONCLUSION: The use of RDRC indicates that a high number of cases in the maxillary anterior area would require augmentation procedures in order to achieve ideal implant placement and restoration.

A two-stage full-arch ridge expansion technique: review of the literature and clinical guidelines.

Ridge expansion techniques have been acknowledged to offer several advantages in the correction of ridge deformities. The expanded defect heals in a similar manner to an extraction socket. In selected cases patients can wear their dentures after surgery. Secondary surgical sites are not a prerequisite, and simultaneous implant placement can be achieved during ridge expansion. The limitation of this technique lies in its inability to create bone vertically. Therefore, it is not indicated for the correction of vertical defects. The application of the split ridge expansion technique has been reported in the literature as it pertains to partially edentulous deficient ridges. The purpose of this article was to present the application of the split ridge expansion technique in the fully edentulous maxilla and discuss the distinction between the immediate or one-stage approach and the delayed or two-stage approach. Histologic results are discussed. Two case reports demonstrate the results that can be obtained with this technique.

Precision of flapless implant placement using real-time surgical navigation: a case series.

PURPOSE: To demonstrate the predictability of flapless surgery using navigation surgery. MATERIALS AND METHODS: Computer-generated preoperative implant planning was compared to actual placement by CT (computerized tomography) scanning of patients before and after surgery. Once pre- and postoperative coordinates of virtual implants were obtained, linear distances and angles were calculated. Coronal and apical errors consisted of the shortest distance from the preoperative planning to the postoperative overlay. RESULTS: Fourteen implants were placed in 6 patients who received CT scans before and after implant placement. Preoperative implant planning using software was compared to actual placement. The average discrepancy of the head of the implant was 0.89 mm +/- 0.53 SD (range, 0.32 to 1.96). The average discrepancy of the apex of the implant was 0.96 mm +/- 0.50 SD (range, 0.25 to 1.99). The average angle discrepancy and standard deviation were 3.78 degrees +/- 2.76 SD (range, 0.60 to 9.87). CONCLUSION: Optical computerized navigation is vulnerable to technological and technical errors. Yet, the present case series suggests that less than 1 mm of mean linear deviation and less than 4 degrees of angular deviation might be attainable.

Accurate transfer of peri-implant soft tissue emergence profile from the provisional crown to the final prosthesis using an emergence profile cast.

BACKGROUND: The use of impression copings to make the final impression results in a master cast in which the soft tissue configuration around the implant platform is circular. Therefore, any soft tissue sculpting developed clinically by the provisional restoration is squandered. PURPOSE: The purpose of this report was to present a method for the precise transfer of the peri-implant soft-tissue developed by a customized provisional restoration to an emergence profile cast. MATERIALS AND METHODS: The emergence profile cast is obtained from an impression of the implant-supported provisional restoration and poured with a soft tissue model material. It is used for the fabrication of the emergence profile of the implant abutment and the cervical section of the crown. CONCLUSION: The technique described is simple, accurate, predictable, and does not require additional chair time for the customization of the impression coping or the fabrication of a new provisional restoration. CLINICAL SIGNIFICANCE: This article describes a technique that results in an implant restoration that mimics accurately in its emergence profile that of the carefully crafted and customized provisional restoration. The reproduction of the soft tissue contour from the provisional to the final restoration results in an improved esthetic outcome of the final restoration.

Advanced concepts in implant dentistry: creating the "aesthetic site foundation".

To obtain optimal and predictable aesthetics, deficiencies caused by soft and particularly hard tissue loss can be managed by various methods, such as orthodontic tooth eruption, socket preservation, and guided bone regeneration. However, in complex cases, these methods are often insufficient. Here, the authors introduce advanced concepts in aesthetic implant dentistry, such as "Aesthetic Site Foundation", "Aesthetic Guided Bone Regeneration" and "Implant Rectangle" that will guide the clinician in the quest to optimal aesthetic outcomes.

Unexpected return of sensation following 4.5 years of paresthesia: case report.

Neural damage leads to a transient or persistent alteration, depending on the severity or type of injury sustained. During the last decade, many investigators reported on paresthesia related to dental implants. In this case report, the patient had presented repeatedly with swelling and suppuration, showing typical signs of peri-implantitis. In addition, the implant was placed in proximity to the mental foramen and possibly had traumatized the mental nerve because the patient had had an altered sensation on his left side for the past 4.5 years. After removal of the implant, a significant diminishing of the paresthesia had occurred, described by the patient as a 40% improvement. Further improvement occurred at 6 and 9 months. In this case report, the findings differ from the current literature in that the return of sensation occurred following a prolonged state of paresthesia. This report documents 2 unique findings. First, an area of persistent paresthesia significantly improved 50 months after the initial injury, upon the removal of the offending implant. Second, the placement of another implant in the same vicinity did not result in recurrent paresthesia.

Distribution of the maxillary artery as it relates to sinus floor augmentation.

PURPOSE: Knowledge of the blood supply to the sinus is of importance in sinus augmentation, both as it pertains to vascularization of the sinus graft and as its location relates to the position of the required lateral osteotomy. The purpose of this study was to investigate the distribution of the endosseous branches of the maxillary artery in the area of the proposed lateral window. MATERIALS AND METHODS: Fifty computerized tomographic (CT) scans from 625 available patients undergoing sinus augmentation surgery at the New York University Department of Implant Dentistry were chosen at random for evaluation. In those cases where the maxillary artery could be identified, measurements were taken to determine the distance between the alveolar crest and the lower border of the vessel. RESULTS: The vessel was radiographically identified in 51.4% of right sinuses and 54.3% of left sinuses in the 50 CT scans. The average height of the artery from the alveolar crest was 16 mm (+/- 3.5 mm). DISCUSSION: and CONCLUSIONS: Because of its location, the intraosseous artery has the potential to cause bleeding complications in approximately 20% of normally positioned lateral window osteotomies. Although a previous anatomic study on cadavers identified the vessel in 100% of the specimens, it could only be visualized in 53% of the CT scans in the present series.

Performance of short implants in partial restorations: 3-year follow-up of Osseotite implants.

Short-length implants should be at a performance disadvantage because of the more limited surface area with which to resist occlusal forces. Nevertheless, anecdotal observations find many short implants performing well in different restorative conditions. This retrospective, multicenter study seeks to compare formally implant performance based on length. The success of 7 and 8.5-mm Osseotite implants (Implant Innovations, Inc., Palm Beach Gardens, FL) was determined as: absence of mobility; no persistent and/or irreversible signs or symptoms of pain, infection, paresthesia, or violation of the mandibular canal; no evidence of peri-implant radiolucency; and no progressive crestal bone loss. Implant location, restoration type, bone density, and smoking status of the patients were recorded. A total of 188 patients received 311 short Osseotite implants that were placed mostly in soft bone and supported 216 partially edentulous cases in the maxilla or mandible. Most restorations (95.2%) are short-span fixed partial dentures placed in the posterior sextants. During 3 years of follow-up, 13 implants failed, yielding a cumulative success rate of 95.8%. In 9 of these cases, failure occurred before prosthetic loading, and in 4, the patient was a smoker. The overall success rate compares favorably with the available literature for the performance of implants in general, and short implants in particular.

The use of a mineralized allograft for sinus augmentation: an interim histological case report from a prospective clinical study.

A prospective clinical research study of various graft materials used for the augmentation of human maxillary sinuses is currently in progress at New York University Department of Implant Dentistry. This interim case report describes the healing response after a sinus augmentation procedure using a new mineralized cancellous bone allograft. The results after 9 months of healing demonstrated a vital bone content of 25.2% in the grafted sinus, as ascertained from a trephine core taken from the superior aspect of the lateral window area. Although the vital bone requirement for implant survival in an augmented sinus is unknown, the 25.2% vital bone demonstrated in this case compares favorably with that reported in the literature for other augmentation materials, including xenografts, alloplasts, and autogenous bone.

A comparison of characteristics of implant failure and survival in periodontally compromised and periodontally healthy patients: a clinical report.

PURPOSE: This study compares implant survival and patterns of implant failure in periodontally compromised and periodontally healthy patients. MATERIALS AND METHODS: In a private periodontal practice, over a 13-year period, implants were placed in both periodontally compromised and periodontally healthy patients. Implants were classified in 5 different groups according to surface texture. Survival rates in each group were compared according to implant location, diameter, length, and phase of treatment. RESULTS: A total of 1,511 implants were placed in 334 patients. One hundred fifty-one of these patients, classified as periodontally compromised patients (PCP), received 923 implants. The remaining 183 patients, classified as periodontally healthy patients (PHP), received 588 implants. The overall survival rate for implants placed in the PHP group was 93.7%, compared to 90.6% in the PCP group. The survival rate of hydroxyapatite-coated implants was 92.6% in the PHP group and 81% in the PCP group. The survival rate of the turned-surface implants was similar in both groups. DISCUSSION: Two types of implant failure were identified. The first was failure of the implant to osseointegrate. This type of failure occurred early in treatment and appeared to be related to smooth-surface implants placed in bone of low density. Failures of this type were distributed equally between the PHP and PCP groups. The second type of failure was related to peri-implantitis. It was observed most often with implants with hydroxyapatite surfaces, occurred as the result of a progressive condition, and was most prevalent in the PCP group. CONCLUSION: Further long-term controlled investigations are needed to determine the influences of implant suface and host susceptibility on implant failure in both PHP and PCP.

Histological evaluation of the Serf EVL evolution implant: a pilot study in a dog model.

PURPOSE: The purpose of this study was to compare bone-to-implant contact (BIC) of the one-stage sandblasted surface EVL implant (SERF, Decines, France) with that of the two-stage turned (machined) Branemark Nobel BioCare implant in a dog model system. MATERIALS AND METHODS: Three 1-year old female beagle dogs (canine) were acquired, examined, and quarantined. In dog no. 1, three test implants were placed on one side of the jaw, and four control implants were placed on the other side. In dog no. 2, two test implants were placed in alternation with two control implants on the left and right sides (total 4 tests, 4 controls). In dog no. 3, three test implants were placed on one side and three control implants on the other. After a 3-month period of healing, the dogs were killed and the jaws sectioned for histological preparation. Eleven implants, six tests, and five controls were available for histological evaluation. RESULTS: The percent of BIC for the test implants varied from 24.9% to 61.6%, with an average of 42.7%. The percent of BIC for the control implants varied from 22.1% to 42.6%, with an average of 27.4%. CONCLUSION: The degree of BIC of the EVL implants was on average greater than that of the turned surface of the Branemark implant. However, because of the limited number of implants placed in this pilot study, the results should be interpreted with caution.

Realities and limitations in the management of the interdental papilla between implants: three case reports.

A predictable, aesthetic result is sometimes difficult to achieve when two or more adjacent implants are placed in the anterior maxilla. Maintenance of the distance from the interproximal crest of bone to the contact point influences the presence or absence of the interdental papilla. The design of the coronal portion of implants currently in the market and the contour of the implant-abutment junction may further affect the biology and reformation of the papilla between two adjacent implants. Through a series of case reports, parameters influencing implant placement are presented.

Regeneration of an osseous peri-implantitis lesion.

This case report concerns the loss of osseous tissue around two hydroxyapatite (HA) Biovent implants, placed in 1993, at sites #30 and #31. The implant in site #31 was positioned with a distal angle, resulting in an ill-fitting prosthesis. This permitted bacterial colonization to set up a periimplantitis. The rough HA coating on the implants further exacerbated the resultant bone loss. In an attempt to rectify the pathology, surgical debridement, antibiotic therapy, bone grafting, and guided tissue regeneration with a barrier membrane were utilized. This case report documents a successful partial repair of osseous housing around these implants.

Immediate loading of osseotite implants: two-year results.

The high success rate of dental implants has changed the quality of life for many patients. Immediate loading finds its application in some clinical cases and certainly adds another modality of treatment for the implant patient. Starting with a couple of implants placed in the mandible and immediately loaded within 72 hours after surgical placement with an overdenture, this concept evolved to immediately loading multiple implants in both the maxilla and the mandible. In this investigation, 11 consecutive patients were treated with 87 screw-shaped endosteal acid-etched, Osseotite implants (3i, Implant Innovations, Inc., Palm Beach Gardens, FL) between June 1998 and June 1999. Two mandibular and two maxillary cases received screw-retained provisional prostheses the day of surgery. Three mandibular and four maxillary cases were loaded 48 hours after surgery with the final screw-retained, porcelain-fused-to-metal prostheses. All implants were followed for 2 to 3 years. Follow-up consisted of clinical as well as radiographic examination. All implants were successful. There was no implant mobility or periimplant radiolucency. The bone level was measured at the 12th and 24th months. The average radiographic bone level from the implant platform to the first bone-to-implant contact was 0.654 mm at the 12th month and 0.946 mm at the 24th month. We conclude that a high success rate can be achieved when implants with a hybrid surface, machined/acid-etched, are immediately loaded within 48 hours after surgical placement in the maxilla and the mandible.