Alessandro Cucchi

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.

Cleaning and decompression of inferior alveolar canal to treat dysesthesia and paresthesia following endodontic treatment of a third molar.

Endodontic overfilling involving the mandibular canal may cause an injury of the inferior alveolar nerve (IAN). We report a case of disabling dysesthesia and paresthesia of a 70-year-old man after endodontic treatment of his mandibular left third molar that caused leakage of root canal filling material into the mandibular canal. After radiographic evaluation, extraction of the third molar and distal osteotomy, a surgical exploration was performed and followed by removal of the material and decompression of the IAN. The patient reported an improvement in sensation and immediate disappearance of dysesthesia already from the first postoperative day.

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.

CUSTOM-MADE TITANIUM MESH FOR MAXILLARY BONE AUGMENTATION WITH IMMEDIATE IMPLANTS AND DELAYED LOADING

No abstract is required for clinical case letters.

Effect of Oral Administration of Bromelain on Postoperative Discomfort After Third Molar Surgery

Introduction: The purpose of this prospective randomized controlled clinical trial was to evaluate the effect of oral administration of bromelain on discomfort after mandibular third molar surgery. Materials and Methods: Eighty-four consecutive patients requiring surgical removal of a single mandibular impacted third molar under local anesthesia were randomly assigned to receiving no drug (control group, Group A), postoperative 40 mg bromelain every 6 hours for 6 days (Group B), preoperative 4 mg dexamethasone sodium phosphate as a submucosal injection (Group C), and preoperative 4 mg dexamethasone sodium phosphate as a submucosal injection plus postoperative 40 mg bromelain every 6 hours for 6 days (Group D). Standardized surgical and analgesic protocols were adopted. Maximum interincisal distance and facial contours were measured at baseline and on postoperative days 2 and 7. Pain was measured objectively by counting the number of analgesic tablets required. Patient perception of the severity of symptoms was assessed with a follow-up questionnaire (PoSSe scale). Results: On postoperative day 2, there was a statistically significant reduction in facial edema in both Groups C and D compared with the control group, but no statistically significant differences were observed between Group B and the control group. At evaluation on postoperative day 7, Group D showed a statistically significant reduction in postoperative swelling compared with the control group. The combined use of bromelain and dexamethasone (Group D) induced a statistically significant reduction in the total number of analgesic tablets taken after surgery compared with the control group. The treatment groups had a limited, nonsignificant effect on trismus when compared with the control group. Conclusions: Bromelain used singly showed moderate anti-inflammatory efficacy, reducing postoperative swelling, albeit not to any significant extent compared with no drug administration. The combined use of bromelain and dexamethasone sodium phosphate yielded the best results in terms of control of postoperative discomfort.

Minimally Invasive Approach Based on Pterygoid and Short Implants for Rehabilitation of an Extremely Atrophic Maxilla: Case Report

Introduction: Extremely atrophic maxillae can be considered the most important indication for three-dimensional maxillary reconstruction. Different bone-augmentation techniques have been suggested to accomplish this. This article illustrates a minimally invasive approach to rehabilitation of the extremely atrophic maxilla. Material and Methods: A 63-year-old male patient was referred for restoration of his totally edentulous maxilla with a fixed full-arch implant-prosthetic rehabilitation. Four short implants in the premaxillary region and 2 longer implants in the pterygomaxillary regions were inserted with piezoelectric implant site preparation. Discussion: At the 1-year follow-up appointment, no clinical or radiographic changes in the soft-tissue contours or crestal bone levels were observed. Conclusion: This surgical approach, based on the combination of short implants in the premaxillary regions and pterygoid implants in the pterygomaxillary regions, represents a way to shorten treatment timing, minimize the risk of surgical complications, and reduce patient discomfort and costs.

Tapered, Double-Lead Threads Single Implants Placed in Fresh Extraction Sockets and Healed Sites of the Posterior Jaws: A Multicenter Randomized Controlled Trial with 1 to 3 Years of Follow-Up

Purpose To evaluate the survival, success, and complication rates of tapered double-lead threads single implants, placed in fresh extraction sockets and healed sites of the posterior jaws. Methods The enrolled patients were randomly divided into 2 groups: in the test group (TG), all implants were inserted at the time of tooth extraction; in the control group (CG), all implants were placed 3 months after extraction. The implants were followed for a period of 1 to 3 years after loading. The main outcomes were implant survival, complications, and implant-crown success. Results Ninety-two patients had 97 installed implants (49 in the TG, 48 in the CG). Only two implants failed, in the TG; the survival rates were therefore 95.9% (47/49) and 100% (48/48) for TG and CG, respectively. In the surviving implants, no complications were reported, for an implant-crown success of 100%. Conclusions Although a significant difference was found in the levels of primary stability between TG and CG, single implants placed in fresh extraction sockets and healed sites of the posterior jaws had similar survival and complication rates. Crestal bone levels and peri-implant bone resorption showed similar values. A longer follow-up period is however required, to confirm these positive outcomes.

Relationship between crestal bone levels and crown-to-implant ratio of ultra-short implants with a micro-rough surface: a 4-year follow-up prospective study.

The aim of this cohort study was to investigate the relationship between crestal bone levels and crown-to-implant ratio of ultra-short implants, after functional loading. Sixty patients with single or partial edentulism and alveolar bone atrophy were enrolled and treated between December 2009 and January 2016. Without using bone-grafting procedures, patients were rehabilitated with ultra-short implants characterized by a microrough surface and a 6-mm length. Clinical and anatomical crown-to-implant (C/I) ratios and crestal bone levels (CBL) were measured after a follow-up period ranging from 12 to 72 months; all peri-implant and prosthetic parameters were recorded. The data collected were statistically analyzed ( P = .05). A total of 47 patients with 66 ultra-short implants were completely followed up according to described protocol. The mean follow-up was 48.5 ± 19.1 months. The mean anatomical C/I ratio was 2.2, while the mean clinical C/I ratio was 2.6 ± 0.6 at baseline and 2.8 ± 0.6 at the last follow-up appointment. Mean CBL as calculated at the baseline was 0.7 ± 0.5 mm, while at the last appointment it measured 1.0 ± 0.5 mm. The overall implant-based success rate was 96.9%, and the mean peri-implant bone loss (PBL) was 0.3 ± 0.3 mm. No statistically significant relationship was found between anatomical or clinical C/I ratio and PBL. Ultra-short implants appear to offer a predictable solution for implant-prosthetic rehabilitation in patients with edentulism and bone atrophy. A high percentage of implants were successful, with minimal crestal bone loss. The high C/I ratio did not appear to influence either peri-implant bone loss or prosthetic complication rates.

The Efficacy of an Anatase-Coated Collar Surface in Inhibiting the Bacterial Colonization of Oral Implants: A Pilot Prospective Study in Humans

PURPOSE The primary prevention of peri-implantitis onset is a key factor in long-term implant success, and the evaluation of the antibacterial efficacy of different implant surfaces is fundamental in this way. The aim of this study was to assess if implants with collars coated with anatase were less subjected to bacterial colonization than implants with noncoated collars, and to investigate how implant bacterial colonization varies over time. MATERIALS AND METHODS Eighteen patients in need of implant-supported rehabilitation were selected to have two adjacent implants placed, one with an anatase-coated collar and one with the collar uncoated. Biofilm samples were collected at four sites around each implant at four different time points. Samples were analyzed through polymerase chain reaction (PCR) to detect and calculate the colonization rate of Aggregactibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, and Prevotella intermedia. RESULTS Due to one patient dropout and two nonosseointegrated implants, 32 out of 36 placed implants were followed up for 12 months, and 128 samples for each time point were collected: in total, 512 biofilm samples were analyzed. The type and rate of bacterial colonization were not significantly different between the two groups at all the intervals. However, the anatase-coated collar showed no proliferation of T forsythia. A significant difference in marginal bone level could be observed at the 12-month follow-up only. No significant difference in the other clinical and radiographic indexes was observed. CONCLUSION In this study, anatase-coated collar implants did not seem to provide significantly different microbiologic outcomes than uncoated collar implants. However, the absence of colonization of the species T forsythia and the slightly smaller peri-implant bone loss at the 12-month follow-up suggest that further investigations on anatase coating are needed. Nevertheless, data on bacterial colonization and crestal bone levels need further investigations to draw meaningful conclusions, due to the statistical power of this pilot study.

Implant rehabilitation of the edentulous jaws: Does tilting of posterior implants at an angle greater than 45° affect bone resorption and implant success?: A retrospective study

PURPOSE This study aimed to (1) investigate the success of posterior implants tilted >45° when 4 immediately loaded implants were used to support full-arch prostheses, eliminating any distal cantilever and (2) examine the effect on marginal bone loss (MBL) of different combinations of anterior multi-unit abutment (MUA) angles and posterior implant tilting angles. MATERIALS AND METHODS Records of patients rehabilitated according to the Columbus Bridge Protocol were analyzed. Peri-implant bone levels (PBLs) and MBL were measured for each implant. The influence of posterior implant tilting angle on PBL, MBL, and implant and prosthetic success rate was investigated. The impact on the same endpoints of different anterior MUA angles, and different combinations of anterior MUA and tilted posterior implant angles was also examined. RESULTS Records of 41 patients were analyzed, for a total of 46 complete rehabilitations, and 142 implants (52 anterior, 63 posterior tilted ≤45° [group 1], and 27 posterior tilted >45° [group 2]). No implants were lost during the follow-up (25.9 months), and no prosthetic complications were reported. Success rate for posterior implants was 100% in group 1 and 96.3% in group 2. Mean MBL differed significantly between the 2 groups (0.45 mm in group 1, 0.66 in group 2 [P = .04]), but not when the analysis was limited to implants in the same jaw. Implant tilting angle did not correlate with MBL and the MUA angle had no effect on bone resorption around posterior implants, neither in the sample as a whole nor in individual patients. CONCLUSIONS Posterior implants tilted >45° to eliminate distal cantilever may be as safe as those tilted less in severely atrophic jaws rehabilitated with immediately loaded, full-arch prostheses supported on 4 implants. Further prospective studies on larger samples of patients and implants and with longer follow-up are needed to confirm these findings.