Immediate Replacement of Single Teeth With Immediately Loaded Implants: Retrospective Analysis of a Clinical Case Series.

INTRODUCTION: The purpose of this retrospective analysis of clinical data was to evaluate the predictability of replacing failing single teeth with immediately placed implants loaded via a transitional (provisional) restoration. MATERIALS AND METHODS: Implants were placed immediately at the time of extraction of failing single teeth that met predetermined inclusion criteria. A detailed protocol was followed to enable immediate loading of the implant with the use of prefabricated abutments in combination with transitional restorations. RESULTS: A total of 375 immediate implants had been placed in 274 patients and loaded immediately. With the certainty of 95%, an estimated overall mean survival rate better than 97.6% was observed after a mean observation period of 36 months. The maximum observation period was 142 months. Four implants had been lost in function. CONCLUSION: Immediate loading of immediately placed implants is a possible treatment option that might be predictably and successfully achieved. Implants of adequate primary stability coupled with a range of prefabricated abutments permit function to be achieved using transitional restorations. The preliminary results of this clinical case series are very promising.

Rehabilitation of Full-Mouth Edentulism: Immediate Loading of Implants Inserted With Computer-Guided Flapless Surgery Versus Conventional Dentures: A 5-Year Multicenter Retrospective Analysis and OHIP Questionnaire.

OBJECTIVE: The purpose of this report is to compare satisfaction of patients rehabilitated with full-mouth fixed prostheses using computer-aided flapless implant placement and immediate loading with patients rehabilitated with conventional removable prostheses. MATERIALS AND METHODS: The study included 30 consecutive fully edentulous patients who received 312 implants and 30 matched controls treated with conventional removable prostheses. Mandible and maxilla were treated in the same surgical session with computer-guided flapless approach using NobelGuide protocol. Prefabricated screw-retained fixed prostheses were inserted at the end of surgery. Clinical and radiographic evaluations were assessed at 6, 12, and 36 months. At baseline and 5 years after prostheses delivery, patients answered OHIP-EDENT questionnaire (Oral Health Impact Profile for Edentulous subjects) to assess satisfaction. RESULTS: The implant survival rate was 97.9%, whereas the average marginal bone loss was 1.9 ± 1.3 mm after 3 years. At 6 months, patients showed significantly greater satisfaction with their fixed rehabilitation as compared to conventional dentures. CONCLUSIONS: The results of this study confirm that rehabilitation with a prefabricated fixed prosthesis supported by implants placed with NobelGuide protocol significantly increases the quality of life in fully edentulous patients when compared with complete dentures.

Osteoporosis and bisphosphonate-related osteonecrosis in a dental school implant patient population.

PURPOSE: Studies have demonstrated an inconsistent association between implant failure and bone mineral density. The prevalence of osteoporosis in US adults has been reported to range from 5% to 10% in women and from 2% to 4% in men. The prevalence of bisphosphonate (BP)-related osteonecrosis of the jaw (BRONJ) has been reported to range from 0% to 4.3% of patients taking oral BPs. The purpose of this study was to calculate the risk of dental implant loss and the incidence of BRONJ in patients with osteoporosis at the University of Kentucky College of Dentistry (UKCD). MATERIALS AND METHODS: This study analyzed data collected from patients who had implants placed between 2000 and 2004 at UKCD. Data were gathered from patient interviews regarding implant survival and patient-satisfaction parameters, and interviews were conducted either chairside at a scheduled maintenance appointment or by telephone interview. RESULTS: Among 203 patients who received 515 implants, the prevalence of osteoporosis was 23.3% for women and 1.2% for men. None of the 20 patients who reported a history of oral BP use exhibited BRONJ, and there were no implant failures in patients with a history of osteoporosis. CONCLUSIONS: In this study, osteoporosis conferred no risk of implant failure, and oral BP therapy was not associated with BRONJ.

Reporting numeric values of complete crowns. Part 2: Retention and resistance theories.

STATEMENT OF PROBLEM: Determining the retention and resistance of a tooth preparation for a complete crown has only existed in theory, and these theories have never been measured on tooth preparations performed in vivo. PURPOSE: The purpose of this study was to measure the theoretical retention and resistance of clinically produced complete crown preparations by using an objective measuring method. MATERIAL AND METHODS: Stone dies from 236 complete crown preparations were collected from dental laboratories. The dies were scanned and analyzed with the coordinate geometry method. Cross-sectional images were captured, and the surface area was measured with a cone frustum and right truncated pyramid formula. Two different theories of resistance form, the "on" or "off" theory (limiting taper) and the linear model (resistance length), were calculated for premolar and molar preparations. RESULTS: The mean surface areas ranged from 33.97 mm(2) to 105.44 mm(2) for the cone frustum formula and 41.75 mm(2) to 117.50 mm(2) for the right truncated pyramid formula. The facial side of maxillary premolars exhibited the highest percentage of resistance form with the limiting taper, at 58%, and the mesial side of the mandibular molars exhibited the lowest percentage of resistance form, at 6%. CONCLUSIONS: The objective method used in this study provides a way for retention and resistance theories to be tested and for further clinical implications to be investigated.

Effect of location on primary stability and healing of dental implants.

PURPOSE: To study implant primary stability and bone healing using resonance frequency analysis in different anatomical locations 4 months after placement. MATERIAL AND METHODS: Fifty-six partially edentulous patients restored by dental implants were included. Overall, 214 implants were placed without bone or soft tissue augmentation. All implants were placed with the same drilling protocol and implant insertion torque (35-40 N · cm). RESULTS: The mean implant stability quotient (ISQ) value at baseline for all the locations was 75.4 mm (95% confidence interval, 74.20-76.59 mm). Higher ISQ values were found in the mandible. A significant difference between ISQ values of each location (P < 0.001) was identified. The mean values obtained showed an increase (3.4%) in all the locations, being greater in the posterior lower and upper maxillae (3.8%), whereas for the anterior maxilla, it was the least (1.5%) 4 months after healing. This increase was statistically significant in the posterior upper and lower maxillae (P < 0.001). CONCLUSION: Higher implant stability was found in mandible compared with maxilla in both periods, immediately after insertion and 4 months later. Therefore, according to ISQ values, restoring implants immediately after insertion or after a healing period of 4 months represents safe time points.

Evaluation of possible prognostic factors for the success, survival, and failure of dental implants.

PURPOSE: To analyze the prognostic factors that are associated with the success, survival, and failure rates of dental implants. MATERIAL AND METHODS: Data including implant sizes, insertion time, implant location, and prosthetic treatment of 1656 implants have been collected, and the association of these factors with success, survival, and failure of implants was analyzed. RESULTS: The success rate was lower for short and maxillary implants. The failure rate of maxillary implants exceeded that of mandibular implants, and the failure rate of implants that were placed in the maxillary anterior region was significantly higher than other regions. The failure rates of implants that were placed 5 years ago or more were higher than those that were placed later. CONCLUSIONS: Anterior maxilla is more critical for implant loss than other sites. Implants in the anterior mandible show better success compared with other locations, and longer implants show better success rates. The learning curve of the clinician influences survival and success rates of dental implants.

One-year survival rate outcomes of innovative dental implants: a prospective clinical study.

PURPOSE: The aim of this research was to evaluate an innovative implant design for different placement and loading protocols. The unique implant is a combination of tapered and cylindrical shape, which is aimed to enhance initial stability and long-term osseointegration. MATERIALS AND METHODS: Four hundred and sixty implants were placed in 141 patients under different placement and loading protocols in similarity to those encountered in a dental office. Implants were followed and evaluated for 1 year to assert the survival rate of the newly introduced implant. RESULTS: The results showed a total of 97.4% survival rate, ranging from 92% to 98.6% depending on the different protocols. There was no statistical difference between the different protocol groups. CONCLUSION: The new implant design showed good results for 1 year of follow-up, comparable with the literature, and could be a good choice for every implant-based procedure.

The relationship between resonance frequency analysis (RFA) and lateral displacement of dental implants: an in vitro study.

This in vitro investigation was conducted to study the relationship between resonance frequency analysis (RFA) and lateral displacement measurements of dental implants. A total of 30 implant sites were prepared in nine fresh bovine bone specimens. The bone density around each preparation was determined by using cone beam computerized tomography (CBCT) and imaging software. Dental implants were then inserted during continuous registration of insertion torque. RFA measurements were performed in perpendicular and parallel to the long axis of the specimens. The bone blocks were embedded in plaster and fixated in a specially designed rig for displacement measurements. A lateral force of 25 N was applied via an abutment perpendicular and parallel to each implant and the displacement measured in µm. In addition, a flex constant (µm N(-1) ) was calculated for each measurement. There was a significant inverse correlation between RFA and lateral implant displacement (µm) measurements and between RFA measurements and the flex constant in both perpendicular and parallel directions in bone (P ≤ 0·001). Moreover, both RFA and displacement measurements correlated with bone density (P ≤ 0·001). It is concluded that RFA measurements reflect the micromobility of dental implants, which in turn is determined by the bone density at the implant site.

Brånemark system implant lengths in the pterygomaxillary region: a retrospective comparison.

PURPOSE: Implants that engage the cortical bone of the pterygomaxillary region help restore dentition to the posterior maxilla. However, proper implant length is required. The purpose of this study was to determine if there is a statistically significant difference in the survival rates between different sized implants placed in the pterygomaxillary region. MATERIALS AND METHODS: All Brånemark System 4.0-mm-diameter implants delivered into the pterygomaxillary region in a single private practice were separated into 7- to 13-mm and 15- to 18-mm groups by retrospective patient chart review. Cumulative survival rates (CSR) were calculated. RESULTS: Of all implants delivered, 930 of the 992 osseointegrated for a CSR of 93.75%. Fifty-nine of the 67 implants in the 7- to 13-mm grouping and 871 of the 925 implants in the 15- to 18-mm grouping osseointegrated for CSRs of 88.06% and 94.16%, respectively. The results were statistically significant (P < 0.05). CONCLUSIONS: The results suggest that increased implant length in the pterygomaxillary region may result in higher osseointegration rates. The implant apex better engages the cortical bone between the medial and lateral pterygoid plates and therefore increases primary and secondary stability.

Implant-retained dental rehabilitation in head and neck cancer patients: an assessment of success and failure.

BACKGROUND: This study aimed to evaluate the rate of osseointegration (ROI) and overall success rate (OSR) of implants placed in native and grafted jaws with or without radiotherapy at a 5-year follow-up in Indian head and neck cancer patients. MATERIAL AND METHODS: Thirty head and neck cancer patients from various socioeconomic strata were accrued. Eighty-five implants were inserted in 17 native and 13 grafted jaws. Nineteen patients received radiation therapy. A 5-year follow-up ROI and OSR of implants were reported. RESULTS: The 5-year ROI and OSR were 88% and 77%, respectively. ROI was 93% for grafted, 85% for native, 83% for irradiated, and 100% for nonirradiated jaws. OSR was 73% for grafted, 80% for native, 71% for irradiated, and 89% for nonirradiated jaws. Patients from higher socioeconomic strata had higher OSR (92%) as compared with those belonging to lower socioeconomic strata (65%). CONCLUSION: The failure rate observed in this study was 24% for implants placed in head and neck cancer patients at a 5-year follow-up.

An evidence-based protocol for immediate rehabilitation of the edentulous patient.

CONTEXT: A procedure using 4 dental fixtures with an immediate-loaded prosthesis for totally edentulous patients is the focus of an evidence-based analysis that uses modern methodologies to review an innovative clinical technique. The long-term outcomes for this surgical and prosthetic treatment for previously or newly edentulated patients by clinical teams worldwide, as well as the author's clinical personal data in a referral-based private practice, are reported in this investigation. EVIDENCE ACQUISITION: An independent research dentist performed the literature review using terms that would identify articles commensurate with this article. The search years for keywords were limited to 2010 and 2011 because the purpose of the article was limited to current thinking and evidence on this specific technique. In this article, the author elected to restrict the literature search to journals that are commonly read and received in his clinical practice on a monthly basis. Because of the specific nature of this procedure, all historical references to the "all-on-4" procedure were also included in the database inquiries. EVIDENCE SYNTHESIS: The literature search revealed that the investigated technique has been reported worldwide by multiple authors using retrospective clinical analyses. In the maxillary jaw, the range of implants placed was 27 to 980 fixtures with 1 to 7 years of follow-up, demonstrating a cumulative implant success rate range of 92.5% to 100%. The mandibular arch demonstrated cumulative success rates of 93.8% to 100% with 1 to 10 years of follow-up with a range of 18 to 980 fixtures being placed. The investigator's own personal clinical statistics compared favorably with other clinical teams, with a total of 120 fixtures being placed in both jaws with 6 years of follow-up with a cumulative survival implant success rate of 100%. Continuous stability of the definitive final prosthesis was above 99% in the largest reported review and 100% for this author's private practice. CONCLUSION: Based on extensive reporting by multiple clinicians, the technique investigated is grounded in good bioengineering basic science, and demonstrates long-term clinical outcomes that can provide highly predictable long-term prosthetic stability for the edentulous patient. This highly focused critically appraised review of individual articles using 4 implants to support a fixed dental prosthesis provides clinicians and patients with a protocol that conservatively and immediately reduces the morbidity associated with the loss of teeth and removable prostheses traditional used to negate edentulism.

Validation of resonance frequency analysis by comparing implant stability quotient values with histomorphometric data.

The study was designed to determine the relationship between implant stability quotient (ISQ) values measured using resonance frequency analysis (RFA) and implant-bone distance measured histomorphometrically. Ten identical implants were equally divided into 2 groups based on primary stability at placement. Osteotomies were prepared in harvested goat femurs. ISQ values were measured and compared with implant-bone distance determined by micrometry. Based on the results, it was concluded that RFA can be used to measure implant stability reliably.

Risk analysis and implants.

According to the Medical Devices Directive, both the preparation for clinical trials and marketing of implants require that a risk analysis is performed. This paper presents a risk analysis for a dental implant in the framework of the risk management process carried out for the preparation of a multi-centre clinical trial, where likely hazards, failure modes and their severities, probabilities and detectabilities are assessed, together with a review of the related scientific literature. The clinical study aimed to evaluate a new ion implantation-based implant surface designed for the promotion of more extensive and faster osseointegration.

The effectiveness of immediate, early, and conventional loading of dental implants: a Cochrane systematic review of randomized controlled clinical trials.

PURPOSE: To test whether there is a difference in success rates between immediately, early, and conventionally loaded implants. MATERIALS AND METHODS: All randomized controlled clinical trials (RCTs) of root-form osseointegrated oral implants having a follow-up of 6 months to 1 year comparing the same osseointegrated root-form oral implants loaded immediately (within 1 week); early (between 1 week to 2 months); or conventionally (after 2 months) were eligible. An exhaustive search was conducted with no language restriction on January 15, 2007. Outcome measures were prosthesis failures, implant failures, and marginal bone levels measured on intraoral radiographs. Screening of eligible studies, quality assessment, and data extraction were conducted in duplicate. Authors were contacted for any missing information. Results were expressed as random effects models using weighted mean differences for continuous outcomes and risk ratios for dichotomous outcomes with 95% confidence intervals. The statistical unit of the analysis was the patient. RESULTS: Twenty RCTs were identified, and 11 trials including a total of 300 patients were included. Six trials compared immediate versus conventional loading, 3 early versus conventional loading, and 2 immediate versus early loading. None of the meta-analyses revealed any statistically significant differences. CONCLUSIONS: It is possible to successfully load dental implants immediately or early after their placement in selected patients, although not all clinicians may achieve optimal results. A high degree of primary implant stability (high value of insertion torque) seems to be 1 of the prerequisites for a successful immediate/early loading procedure. More well-designed RCTs are needed. Priority should be given to trials comparing immediately versus early loaded implants. These trials should be reported according to the CONSORT guidelines (www.consort-statement.org).

Axial-wall inclination angle and vertical height interactions in molar full crown preparations.

OBJECTIVE: This study has been designed to evaluate the interaction of axial wall heights with inclination angles in full crown tooth preparations. The interaction of these parameters was related to the resulting preparation surface area. MATERIALS AND METHODS: A right regular pyramid was used to simulate a single mandibular molar preparation with known convergence angles and vertical heights. Various combinations of these two variables allowed the calculation of surface areas with a formula for the area of a pyramid and right triangles through trigonometric manipulations. The pyramidal model system had a 9-mm square base with vertical heights from 3- to 5-mm and single-side inclination angles from 2 to 25 degrees. The occlusal surface was a flat, square or rectangular surface and was included in the total area. RESULTS: A percentage of surface area lost or gained served as the dependent variables. The significance levels were set at 10.0% or greater magnitude of loss/gain in a surface area compared to the ideal 2 degree-level. Significant area loss was demonstrated in all alpha-level comparisons. The largest change was found in the 5-mm height grouping compared to the 3-mm height grouping, -36.6% difference between groups at the 2 degree-level. CONCLUSIONS: Axial single-side inclination angles greater than 10 degrees in 3- and 4-mm height-molars are detrimental to maximum surface area in full crown restorations. The 5-mm axial wall height with < or = 10 degree single wall has been shown to maximize the luting agent surface area between restoration and tooth structure.

Retrospective Study of Survival of Extraoral Endosseous Craniofacial Implants in Head and Neck Surgery Patients.

PURPOSE: To determine the survival rate of implants placed in different craniofacial locations and factors affecting survival. MATERIALS AND METHODS: This study retrospectively reviewed a consecutive series of patients treated at the Royal Melbourne Hospital who received craniofacial implants for an array of benign and malignant conditions. Implant survival per site and cumulative survival were determined. Surgical and implant variables were assessed using the Kaplan-Meier and Cox Proportional Hazards Models. RESULTS: Fifty-two patients had 156 implants placed to reconstruct the nose, orbit, and ears. A total of 43 implants failed (overall survival: 72.4%) in the orbital (29/63, failure rate: 46%) and auricular sites (14/70, failure rate: 17%). No implants failed in the nasal site (0/9). Three-, 5-, and 10-year cumulative survival was also determined. Independent risk factors for decreased survival included postoperative radiation therapy (P = .005, RR: 3.2, 95% CI: 1.4 to 7.0), implants placed in the orbit (P = .004, RR: 5.0, 95% CI: 1.6 to 15.2), and implants that were not loaded with a prosthesis (P = .007, RR: 2.7, 95% CI: 1.3 to 5.4). CONCLUSION: Failure rates varied according to site in this cohort of patients. A number of independent risk factors affecting implant survival in extraoral sites were identified.

A retrospective evaluation of 1,387 single-tooth implants: a 6-year follow-up.

BACKGROUND: The aim of this study was to evaluate the overall survival rate and factors that affect the clinical outcome of 1,387 consecutively placed implant-supported single restorations up to 6 years. METHODS: During 6 years (1999 to 2005), 1,387 implants were placed in 1,215 subjects (1,073 males and 142 females) who required single-tooth replacements. The average time from implant placement was 2.7 +/- 3.27 years. Implants were mostly placed in the maxillary premolar area (39.5%) followed by the anterior maxillary area (28.7%). Implant survival and location, need for bone augmentation, and implant dimensions were recorded and analyzed. RESULTS: Failed implants totaled 96, resulting in an overall survival rate of 93.1%. The vast majority of failures (94.8%) occurred during the first year following implant placement. Bone augmentation was performed in 9.7% of the implants with a 92.5% survival rate, similar to the survival rate of non-augmented areas (93.1%; P = 0.79). The average implant length was 13.3 mm, ranging from 8 to 16 mm. Longer implants (> or =11 mm) showed similar survival rates as implants <11 mm (93.2% versus 90.2%, respectively; P = 0.4). Implant width ranged between 3.25 to 5 mm (mean 3.9), with no effect on implant survival (P = 0.43). There was a significant difference in implant survival according to the anatomic zone of implant placement (P = 0.0075). The maxillary premolar area showed the highest survival rate (96.2%). CONCLUSION: Implant-supported single-tooth replacement is a predictable procedure with good survival rates up to 6 years.

Study of the colors and retention of over-the-counter cosmetic veneers.

The purpose of this study was to observe the tooth colors and retention of a cosmetic veneer Fiche Pearl On containing shellac and five experimental formulations containing benzoin gum and ethyl cellulose. Tooth color was measured with a spectrophotometer before and after application of the veneers to the buccal or labial surface of experimental teeth. Through both in vitro and in vivo studies, the retention rates of veneers were assessed. In terms of color difference (deltaE*ab) between before and after veneer application, it ranged from 4.3 (Fiche Pearl On) to 15.0 (experimental formulation White Plus). In terms of retention rate, in vitro test found the retention rate of experimental formulation White Plus was significantly higher than that of Fiche Pearl On. In in vivo test where subjects were permitted to drink water and tea, it was found that the retention rate after two hours ranged from 94.0 to 98.5%. In conclusion, teeth applied with the experimental cosmetic veneer formulations showed better color and retention than teeth with Fiche.

Implant survival and patient satisfaction of reduced diameter implants made from a titanium-zirconium alloy: A retrospective cohort study with 550 implants in 311 patients.

The aim of the study was to evaluate implant survival of reduced-diameter implants compared to regular-diameter implants. A retrospective evaluation of 154 Straumann Bone Level Roxolid® implants (diameter 3.3 mm) with SLActive®-surface in 107 patients, which were inserted between 2009 and 2010 in private practice, was performed. The mean observation period was 22.4 ± 8.2 months. 396 Straumann SLActive® implants (4.1 mm and 4.8 mm) in 204 patients, with an observation period of 28.4 ± 10.1 months served as control group. Implant survival rate, resonance frequency analysis and patient satisfaction were evaluated. The implant survival rate was 97.4% in the test vs. 98.5% in the control group. Resonance frequency analysis showed statistically significant lower values for the reduced-diameter implants. Patient satisfaction showed no significant difference between the test and the control group. Reduced-diameter implants displayed high survival rates during the period investigated and represent a convincing treatment alternative. Long-term follow-up investigations confirmed the high implant survival rates of 96.8% (after 69.7 ± 12.3 months) in the test group and 98.5% (after 76.0 ± 13.6 months) in the control group.

Polygonal Area of Prosthesis Support with Straight and Tilted Dental Implants in Edentulous Maxillae.

PURPOSE: The aim of this in vitro study was to assess the increase in the polygonal area of implant-retained prosthesis supports in edentulous maxillae with the use of tilted distal implants compared with the use of straight distal implants, using a variety of implant lengths. MATERIALS AND METHODS: A total of 25 DICOM datasets of atrophic edentulous maxillae were provided. Bone augmentations in the molar region had to be avoided. Two straight reference implants were virtually inserted in the anterior region. Two additional implants were placed far distally on both sides (4 groups: [1] straight, 12-mm length; [2] straight, 10 mm; [3] straight, 8 mm; [4] tilted, 12-16 mm). The resulting implant-supported polygon was measured for each of the 4 groups using three-dimensional planning software. RESULTS: The mean sagittal depth of the supported polygon in Group 1 was 9.9 mm (standard deviation [SD] 4.4) on the right and 10.2 mm (SD 4.4) on the left, and it was 33.7 mm (SD 5.8) in width. For Group 2, the mean sagittal depth was 11.5 mm (SD 5.0) on the right and 11.9 mm (SD 4.7) on the left, and the width was 35.2 mm (SD 5.6). The measurements for Group 3 were 13.8 mm (SD 4.9) deep on the right, 13.8 mm (SD 5.1) deep on the left, and 37.0 mm (SD 5.4) in width. For Group 4, the depth was 15.8 mm (SD 4.9) on the right and 16.4 mm (SD 5.8) on the left, and the width was 39.0 mm (SD 5.1). CONCLUSION: The area of implant-retained prosthesis support can be enlarged by the use of tilted implants (12 to 16 mm in length, 42 to 45 degrees) compared to the use of straight 8-mm implants (resulting increase: about 15%).