Luciano Malchiodi

Influence of crown-implant ratio on implant success rates and crestal bone levels: a 36-month follow-up prospective study.

OBJECTIVES The aim of this prospective study was to determine how the crown-implant ratio (C/I ratio) influences crestal bone loss and implant success rates after a 3-year follow-up, using implants with a sintered porous surface (SPS). MATERIALS AND METHODS On the basis of preestablished inclusion and exclusion criteria, 151 of a cohort of 160 patients with single or partial edentulism were selected as eligible for the study. The 151 patients were treated consecutively from 2005 to 2007 using 280 SPS implants, which were restored with a single crown or a partial fixed denture. The data collection included both clinical and anatomical C/I ratios; other implant prosthetic factors were also recorded. Implants were divided into three groups according to the C/I ratio. Clinical and radiographic examinations were scheduled over a 36-month follow-up of functional loading according to a well-established protocol generally applied to determine implant success rates and crestal bone levels. Statistical analysis was used to determine any significant differences or correlations (P = 0.05). RESULTS A total of 259 SPS implants in 136 patients were followed up for 36 months. According to the success criteria, the overall implant-based success rate was 98.1%, and the mean peri-implant bone loss (PBL) was 0.48 ± 0.29 mm. Statistical analysis revealed significant correlation between implant success rate and C/I ratio (P < 0.05) and between PBL and C/I ratio (P < 0.05). The critical threshold value of the anatomical and clinical C/I ratio for avoiding excessive bone loss or implant failure was 3.10 and 3.40. CONCLUSION This prospective cohort study revealed that SPS implants offer a predictable solution for implant prosthetic rehabilitation in patients with edentulism characterized by different alveolar bone atrophy. From the biomechanical point of view, the C/I ratio would appear to be the main parameter capable of influencing implant success and crestal bone loss. Consequently, it is important not to exceed the threshold values in order to avoid excessive stress at the bone-implant interface capable of resulting in excessive crestal bone loss or implant failure.

Evaluation of the esthetic results of 64 nonfunctional immediately loaded postextraction implants in the maxilla: correlation between interproximal alveolar crest and soft tissues at 3 years of follow-up.

PURPOSE Many authors have emphasized that immediate loading protocols enable better esthetic results to be achieved compared with delayed loading, especially in the case of postextraction implants that are capable of maintaining the original esthetics of soft tissues. The aim of this study was to establish correlations between the interproximal crest, interproximal papilla, and marginal facial gingiva of immediately loaded postextraction implants by evaluating clinical and radiographic data. MATERIALS AND METHODS Fifty-eight consecutive patients underwent a tooth extraction and immediate implant placement with 64 postextraction implants, which were immediately loaded using a provisional single crown from June 2005 to December 2006. At 6 months after surgery, all implants were restored with a definitive single crown. Clinical and radiographic data were recorded at the time of surgery, at the time of definitive restoration, and after 3 years of functioning, in order to evaluate soft tissues esthetics and bone tissue condition. Statistical analysis was used to assess significant correlations between the interproximal crest, interproximal papilla, and marginal facial gingiva (p = 0.05). RESULTS After 3 years of functioning, the implant success rate was 100% because no implants had failed. All parameters were stable and steady during the 3-year follow-up. The regression test revealed a statistically significant correlation between interproximal crest levels and interproximal papilla volume (p = 0.0134), and also between interproximal crest levels and marginal gingiva levels (p = 0.0226). CONCLUSIONS Postextraction immediately loaded implants represent a predictable technique that should be considered the treatment of choice in cases of single anterior tooth restoration and other cases. Esthetic results seem to depend on correct positioning of the implants, considering the correlation between bone tissue and related soft tissues. Maintaining the original condition of both bone and soft tissues around the tooth to be removed is the key to obtaining optimal esthetic outcomes.

Long-Term Results of Immediately Loaded Fast Bone Regeneration–Coated Implants Placed in Fresh Extraction Sites in the Upper Jaw

Recently, many authors have investigated the results of immediately loaded implants in fresh extraction sites, reporting favorable success rates, but only a few studies have included a long-term follow-up in the maxilla with analysis of clinical and radiographic data. The aim of this study was to evaluate the predictability of the immediate loading protocol with fast bone regeneration (FBR)-coated implants placed in postextractive sites in the maxilla, considering the success rate after at least 5 years of follow-up. Moreover, the clinical and radiographic results are evaluated in terms of soft tissue conditions and crestal bone loss values. One hundred fifty-eight implants were inserted following dental extraction in 70 consecutively operated patients. Each implant was immediately prosthesized. The data were collected before surgical planning, at the time of insertion, and after 3 and 5 years of occlusal loading. Specific success criteria were used to assess the success rate of immediately loaded postextraction implants. Clinical and radiographic examinations were used to determine long-term results. After a 5-year follow-up, 2 implants were lost, with a cumulative success rate of 98.7%. The radiographic and clinical data revealed well-maintained hard and soft tissues, with acceptable long-term results. The use of immediately loaded FBR-coated implants in fresh extraction sockets is shown to be a predictable technique if implants are inserted in selected cases and positioned with great care, following thorough preoperative analysis.

Computer-assisted surgery: double surgical guides for immediate loading of implants in maxillary postextractive sites.

Implant-supported prostheses are a predictable treatment of totally edentulous patients. Progresses in implantology allowed realizing prostheses that are supported by immediately loading implants. Implants can be inserted in the healed site as fresh extraction sites, without differences about long-term results. Using computer-assisted surgery, it is possible to insert implants in a predetermined position and to create a prostheses, which can be immediately fixed on the implants. Patients have major comfort and an immediate aesthetic and functional result. The use of computer-assisted surgery in fresh extraction sites is a procedure that has not been evaluated because of technical difficulties: teeth extraction eliminates references for surgical guides. The absence of guidelines to treat dentulous areas is often likely caused by lack of computer-assisted surgery: we attempted to use this procedure to replace residual teeth with an immediate implant prosthetic rehabilitation. The aim of this clinical report was to show the possibility to apply computer-assisted surgery in dentulous patient using a double surgical template: one before extraction and the other after extraction of selected teeth.

Delayed progressive haematoma after Le Fort I osteotomy: A possible severe complication in orthognatic surgery

Although the Le Fort I osteotomy is a safe surgical technique, many complications have been reported. We present a case of an extended cervico-facial haematoma due to delayed bleeding from the terminal branches of the maxillary artery after orthognatic surgery. A 23-year-old man was referred to our observation for the surgical correction of a class III asymmetric malocclusion. The patient underwent a Le Fort I osteotomy, with impaction of the maxilla, associated with an Epker mandibular bilateral sagittal split osteotomy, with maxillary advancement and rigid internal fixation of the mandible with four miniplates and another four for the upper maxilla as well. The first post-surgery day, the patient developed a gradual dispnea together with neck swelling. By second postoperative day, the patients general condition improved with a progressive normalization of laboratory tests values. The Computerised Axial Tomography (CAT) scan confirmed a decrease in the parapharyngeal thickening. Total recovery was achieved within two months, the final clinical check showed a healthy appearance with good occlusion. An increased knowledge of the basic biology of the Le Fort I osteotomy, the development of instruments specially designed for the Le Fort I procedure and the use of hypotensive anaesthesia could reduce the morbidity and duration of this procedure.

Immediate function of partial fixed rehabilitation with axial and tilted implants having intrasinus insertion.

AbstractImplant-supported rehabilitation of the posterior maxilla could be challenging because hyperpneumatization of the maxillary sinus might reduce the bone height. In this study, the authors report preliminary results of a new treatment modality for the partial fixed rehabilitation of posterior maxilla with immediate function by using 1 anterior axial implant and 1 posterior tilted implant with intrasinus mesial insertion.From 2009 to 2011, 10 patients (6 women and 4 men) with missing upper premolars and molars were recruited and treated accordingto this protocol. Each patient received a partial fixed bridge supported by 1 axial anterior implant and 1 posterior implant placed with a 30-degree mesial inclination and intrasinus insertion. Autologous bone was positioned to fill the maxillary sinus cavity and to cover the exposed implant surface after elevation of the anterior sinus membrane. A prosthesis with immediate function was positioned within 3 hours, whereas a CAD/CAM final restoration was delivered 6 months later. Follow-ups at 6 and 12 months, and then annually, were scheduled. At each follow-up, plaque level and bleeding scores were assessed, and radiographic evaluation of marginal bone level change was performed at 1 year. The patients were followed up for a mean of 50 months (range, 42–57 mo). No implants were lost, and all prostheses were stable and functional, reporting 100% of implant and prosthetic success rates. After 1 year, bone loss had a mean (SD) of 1.0 (0.4) and 0.9 (0.5) mm for axial and tilted implants, respectively, with no statistically significant differences between them (P > 0.05).The preliminary results suggest that this approach could allow the rehabilitation of posterior maxilla with immediate function in case of reduced bone volume, representing an alternative technique to bone grafting, short implants, and zygomatic or pterygoid implants.

Primary and Secondary Stability of Implants in Postextraction and Healed Sites: A Randomized Controlled Clinical Trial

PURPOSE This randomized clinical trial aimed to investigate the relationships between insertion torque, implant stability quotient (ISQ), and crestal bone loss (CBL) of implants placed in fresh or 12-week healed extraction sites. MATERIALS AND METHODS Forty patients were randomly assigned to one of two groups and had one implant placed immediately (test group, n = 20) or 12 weeks after extraction (control group, n = 20) at premolar or molar sites. For all implants, insertion torque and ISQ scores at insertion and loading were recorded. Patients were followed for up to 12 months. RESULTS Implant success was 100% in both groups. No differences were observed concerning both ISQ at insertion and ISQ at loading. A stronger correlation was detected between ISQ at insertion and insertion torque in the postextractive group (R = 0.83), than in the delayed group (R = 0.39), while ISQ at loading and insertion torque showed no correlation. CBL at 12 months was significantly different between test (0.68 ± 0.43 mm) and control (0.40 ± 0.26 mm, P = .02) groups. CONCLUSION Implant placement timing (immediate or delayed) may affect correlation between insertion torque and ISQ at insertion with ISQ at loading. While insertion torque influences ISQ at insertion, it does not affect ISQ at loading because of successful osseointegration. Postextraction and delayed implants seem to have similar ISQ at insertion and at loading, but different CBL after 12 months of follow-up because of postextraction bone remodeling.

Peri‐implant conditions around sintered porous‐surfaced (SPS) implants. A 36‐month prospective cohort study

OBJECTIVES The specific aim of this study was to assess sintered porous-surfaced (SPS) implant system from a biological point of view, through a prospective study of the health status and the evolution of the peri-implant tissues over time and analysis of the changes observed in the various peri-implant parameters. MATERIAL AND METHODS Hundred and fifty-one patients were treated consecutively from 2005 to 2007 using 280 SPS implants, which were restored with a single crown or a partial fixed denture. To accurately monitor the health and biological evolution of peri-implant soft and hard tissues, a number of clinical parameters were adopted, such as the modified Plaque Index (mPI), the modified sulcus Bleeding Index (mBI), Peri-implant Probing Depth (PPD), and Crestal Bone Level (CBL). Clinical and radiographic examinations were scheduled over a 36-month follow-up of functional loading according to a well-established protocol generally applied to determine implant success rates and Peri-implant Bone Loss (PBL). Statistical analysis was used to determine any significant differences or correlations (P = 0.05). RESULTS A total of 259 SPS implants in 136 patients were followed up for 36 months. According to Busers success criteria, the overall implant-based success rate was 98.1% and the mean PBL was 0.48 ± 0.29 mm. MBI and mPI mean values showed statistically significant differences between baseline and follow-up analyses (P < 0.001). No statistically significant differences in mean PPD values were found between baseline and control analyses (P = 0.060). CONCLUSION This prospective cohort study revealed that the biological behavior of SPS implant system was characterized by high tissue stability during the observation period, both as regards soft and hard tissues. In particular, the crestal bone remodeling pattern was very similar to that reported in other studies, confirming that the bone loss around SPS implants, at least at 36 months, seems to be predictable.

Evaluation of Ultrashort and Longer Implants with Microrough Surfaces: Results of a 24- to 36-Month Prospective Study

PURPOSE The aim of this prospective study was to establish if ultrashort implants are a reliable therapeutic solution by evaluating their effect on mean crestal bone loss and assessing their survival and success rates. MATERIALS AND METHODS Patients were treated using 6-, 9-, and 11-mm-long implants with sandblasted and acid-etched surfaces and fitted with fixed partial prostheses. Clinical and radiographic examinations were scheduled yearly. Data collected included the implant positioning site, implant length and diameter, peri-implant bone loss (PBL), and clinical and anatomical C/I ratios. RESULTS One hundred eleven implants (6-mm-long, 30.6%) were positioned; two implants were lost before loading. During the 36-month followup, no other implants were lost (98.2% survival rate, 100% from loading), but four implants did not meet the criteria for success, due to excessive crestal bone loss, resulting in a 94.6% success rate, 96.3% from loading. Success rates and peri-implant bone loss were not significantly different among implants with different lengths. No correlation was observed between implant length and bone resorption. CONCLUSION Six-millimeter-long implants did not show different results in comparison with 9- and 11-mm-long implants. They can be considered a reliable solution for implant prosthetic rehabilitation and a dependable and minimally invasive therapeutic option in areas showing severe bone resorption.

Peri-implant bone response around a human hydroxyapatite-coated implant retrieved after a 10-year loading period: a case report.

This case report presents a histologic and histomorphometric evaluation of the peri-implant tissues of a HA-coated implant retrieved due to peri-implantitis after a 10-year loading period. The implant was retrieved with a trephine and treated to obtain thin ground sections. At low-power magnification mostly compact, mature bone with small marrow spaces could be observed at the interface with the implant. The coating was always present in the areas where bone was detected, the bone was always in close contact with the coating, and there was no detachment between the metal and coating or between the coating and bone. Areas of bone remodeling were demonstrated by the presence of many secondary osteons and reversal lines close to the implant surface. The bone-implant contact percentage was 36.3% ± 1.2%. The percentage of the implant surface covered by the HA coating without bone, where bone may have detached during retrieval, was 32.6% ± 2.8%. This HA-coated implant, continued to demonstrate more than adequate BIC after many years of function and the potential to maintain osseointegration in the long term.