Vascular and neurosensory evaluation in relation to lingual canal anatomy after mandibular midline implant installation in edentulous patients

Objectives The aim of this study is to investigate vascular and neurosensory complications in edentulous patients following the installation of mandibular midline single implants in relation to lingual canals. Materials and methods After performing a cone beam computed tomography scan for the 50 recruited patients, the relationship between the potential implant site and the lingual canals was assessed, and all vascular and neurosensory complications were recorded. Results Six patients (12%) reported profuse bleeding during implant placement, and 13 (26%) reported transient neurosensory changes, which were resolved after 3 months. According to the virtual implant planning, 44 patients (88%) would have their implants touching the lingual canals, six of them reported vascular changes (14%), and 12 out of 44 patients reported neurosensory changes (27%). For the six patients who would have their implants not touching the lingual canals, one patient reported transient neurosensory changes. Conclusions The mandibular lingual canals are constant anatomic landmarks. Injury to the supra-spinosum lingual canals may occur during midline implant placement, depending on the implant length and the bone height. Clinical relevance Despite that injury to the supra-spinosum lingual canals during implant insertion does not result in permanent vascular or neurosensory complications, caution is required to avoid the perforation of the lingual cortices.

The effect of Implant length and diameter on stress distribution of tooth-implant and implant supported prostheses:An in-vitro finite element study

The aim of this study is to evaluate the effectiveness of the implant diameter and length on force dissemination of tooth-implant and implant retained fixed restorations. A finite analysis model was used via a 3D simulation of a unilateral mandibular Kennedy Class I arch. Through thresholding the resultant assembly, a region of interest was selected from the CT scan. Details of the diameter (D) and length (L) of implant were introduced. Ds used were 3.7, 4.7, and 5.7, while Ls used were 10, 11.5, and 13. The constant was the use of rigid connectors in both designs (implant–implant and implant–tooth fixed partial dentures) and the mesial implant (D 3.7 and L 11.5). Stress in cancellous bone around mesial abutment, which is the second premolar in tooth-implant FPD and mesial implant in the implant-implant fixed partial denture (FPD), revealed that the stress was significantly lower in tooth-implant FPD when compared to implant-implant FPD (21.1±0.00 versus 46.1±0.00, p <0.001). Stress distribution in the bone around any implant depends on several factors such as diameter, length, and tooth-implant vs. implant-implant support. The implant diameter was more significant for improved stress distribution than implant length. A moderate increase in the length of the implant consequently reduced stress.

The Effect of Recipient Jaw and Implant Dimensions on Pre- and Post- Loading Dental Implant Stability: A Prospective Clinical Study

Background: Implant stability is a mandatory factor for dental implant (DI) osseointegration and long-term success. The aim of this study was to evaluate the effect of implant length, diameter, and recipient jaw on the pre- and post-functional loading stability. Materials and methods: This study included 17 healthy patients with an age range of 24-61 years. Twenty-two DI were inserted into healed extraction sockets to replace missing tooth/ teeth in premolar and molar regions in upper and lower jaws. Implant stability was measured for each implant and was recorded as implant stability quotient (ISQ) immediately (ISQ0), and at 8 (ISQ8) and 12 (ISQ12) weeks postoperatively, as well as post-functional loading (ISQPFL). The pattern of implant stability changes throughout the study period and its correlation with the recipient jaw and the DI dimensions were evaluated. Results: There was a significant difference in ISQ values throughout the study. DI stability in the maxilla was significantly higher than that in mandible for the ISQ0, with no significant effect for the rest time points. The effect of implant diameter was significant with DI of 4.1mm diameter being more stable. While for the length, there was no significant difference regarding its effect on ISQ values through-out the study period. Conclusions: DI inserted in the maxilla demonstrated better primary stability with no effect of recipient jaw on secondary stability and after functional loading, also DI with wider diameter had better stability throughout the study whereas DI length showed no significant effect on stability

Peri-implantitis: explantation versus peri-implant regeneration

Peri-implantitis is a complication in implantprosthetic rehabilitation that causes morpho-functional, masticatory and aesthetic disorders. Depending on the severity it can be approached by conservative surgical or radical treatment. The aim of the paper is the comparative analysis of conservative surgical methods (implant preservation) versus radical (explantation). We studied 2 patients who came to the SRL “Omni Dent” clinic with peri-implantitis. Manifestation, treatment and evolution in both patients were compared. Analysis criteria: bone defect extension, soft tissue appearance, tissue regeneration, implant-prosthetic rehabilitation time. In RI patient there were changes in color and appearance of the peri-implant soft tissues (hyperemia, edema, purulent discharge), peri-implant radiolucency on the entire implant surface; in the TM patient there were the same clinical signs but limited to ½ implant length. RI patient underwent explantation with re-implantation in the neighboring region 2.4 after 4 months with prosthesis fixing after another 4 months. Tissue regeneration evolved without complications. In TM patient was decided to keep the implant through curettage, implantoplasty and bone addition. Prosthetic rehabilitation followed later without complications. Timely addressing would prevent the development of complications with implant loss. The insignificant loss of peri-implant tissues can be recovered with the preservation of the implant, in the extended defects the optimal solution is the explantation with the subsequent implantprosthetic rehabilitation.

Reliability and Correlation of Different Devices for the Evaluation of Primary Implant Stability: An In Vitro Study

Our aim was to analyze the correlation between the IT evaluated by a surgical motor and the primary implant stability (ISQ) measured by two RFA devices, Osstell and Penguin, in an in vitro model. This study examines the effect of bone type (soft or dense), implant length (13 mm or 8 mm), and implant design (CC: conical connection; IH: internal hexagon), on this correlation. Ninety-six implants were inserted using a surgical motor (IT) into two types of synthetic foam blocks. Initial measurements for both the peak IT and ISQ were recorded at the point when implant insertion was stopped by the surgical motor, and the final measurements were recorded when the implant was completely inserted into the synthetic blocks using only the RFA devices. Our null hypothesis was that there is a good correlation between the devices, independent of the implant length, design, or bone type. We found a positive, significant correlation between the IT, and the Osstell and Penguin devices. Implant length and bone type did not affect this correlation. The correlation between the devices in the CC design was maintained; however, in the IH design it was maintained only between the RFA devices. We concluded that there is a high positive correlation between the IT and ISQ from a mechanical perspective, which was not affected by bone type or implant length but was affected by the implant design.

Implant removal associated complications after ESIN osteosynthesis in pediatric fractures

Purpose ESIN (elastic stable intramedullary nailing) is considered the gold standard for various pediatric fractures. The aim of this study was to analyze the incidence and type of complications during or after TEN (titanium elastic nail) removal. Methods A retrospective data analysis was performed. Metal removal associated complications and preoperative extraosseous length/outlet angle of TENs as possible causes of complications were assessed. Results The complication rate in 384 TEN removals was 3.1% (n = 12). One major complication (rupture of M. extensor pollicis brevis) was documented. One refracture at the forearm occurred, however, remodeling prior TEN removal was completed. Ten minor complications were temporary or without irreversible restrictions (3 infections, 5 scaring/granuloma, 2 temporary paraesthesia). In 38 cases (16 forearms, 10 femora, 9 humeri, 3 lower legs), intra-operative fluoroscopy had to be used to locate the implants. In patients with forearm fractures, extraosseous implant length was relatively shorter than in cases without fluoroscopy (p = 0.01), but outlet angle of TENs was not significantly different in these two groups (28.5° vs 25.6°). In patients with femur fractures, extraosseous implant length and outlet angle were tendentially shorter, respectively, lower, but this did not reach statistical significance. Conclusion Removal of TENs after ESIN is a safe procedure with a low complication rate. Technically inaccurate TEN implantation makes removal more difficult and complicated. To prevent an untimely removal and patient discomfort, nail ends must be exactly positioned and cut. Intraoperative complications may be minimized with removal of TENs before signs of overgrowth. Evidence Level III, retrospective.

Accuracy of digital planning in zygomatic implants

Background Zygomatic implants have been described as a therapeutic alternative for patients with severe maxillary atrophy in order to avoid bone augmentation procedures. Taking that into account, in these treatments, the key factor is the position of the implant, the virtual surgical planning (VSP) is widespread among most clinicians before surgery on the patient. However, there are no studies which evaluate the clinical relevance of these VSP. The aim of this study is to determine whether digital planning on zygomatic implants has any influence on the implant dimensions and position, even when performing conventional surgery afterwards. Results Fourteen zygomatic implants were placed in four patients. Pre-operative and post-operative helicoidal computed tomography were performed to each patient to allow the comparison between the digital planning and the final position of implants. Tridimensional deviation (TD), mesio-distal deviation (MDD), bucco-palatine deviation (BPD), and apico-coronal deviation (ACD) were evaluated as well as angular deviation (AD). Significative differences in apical TD were observed with a mean of 6.114 ± 4.28 mm (p < 0.05). Regarding implant position, only implants placed in the area of the first right molar reported significant differences (p < 0.05) for ACD. Also, implant length larger than 45 mm showed BPD significative differences (p < 0.05). Conclusions Zygomatic implant surgery is a complex surgical procedure, and although VSP is a useful tool which helps the clinician determine the number and the length of zygomatic implants as well as its proper position, surgical experience is still mandatory.

The Impact of Dental Implant Length on Failure Rates: A Systematic Review and Meta-Analysis

The present review aimed to evaluate the impact of implant length on failure rates between short (<10 mm) and long (≥10 mm) dental implants. An electronic search was undertaken in three databases, as well as a manual search of journals. Implant failure was the outcome evaluated. Meta-analysis was performed in addition to a meta-regression in order to verify how the risk ratio (RR) was associated with the follow-up time. The review included 353 publications. Altogether, there were 25,490 short and 159,435 long implants. Pairwise meta-analysis showed that short implants had a higher failure risk than long implants (RR 2.437, p < 0.001). There was a decrease in the probability of implant failure with longer implants when implants of different length groups were compared. A sensitivity analysis, which plotted together only studies with follow-up times of 7 years or less, resulted in an estimated increase of 0.6 in RR for every additional month of follow-up. In conclusion, short implants showed a 2.5 times higher risk of failure than long implants. Implant failure is multifactorial, and the implant length is only one of the many factors contributing to the loss of an implant. A good treatment plan and the patient’s general health should be taken into account when planning for an implant treatment.

The survival rates and risk factors of implants in the early stage: a retrospective study

Background Few large-sample studies in China have focused on the early survival of dental implants. The present study aimed to report the early survival rates of implants and determine the related influencing factors. Methods All patients receiving dental implants at our institution between 2006 and 2017 were included. The endpoint of the study was early survival rates of implants, according to gender, age, maxilla/mandible, dental position, bone augmentation, bone augmentation category, immediate implant, submerged implant category, implant diameter, implant length, implant torque, and other related factors. Initially, SPSS22.0 was used for statistical analysis. The Chi-square test was used to screen all factors, and those with p < 0.05 were further introduced into a multiple logistic regression model to illustrate the risk factors for early survival rates of implants. Results In this study, we included 1078 cases (601 males and 477 females) with 2053 implants. After implantation, 1974 implants were retained, and the early survival rate was 96.15%. Patients aged 30–60 years (OR 2.392), with Class I bone quality (OR 3.689), bone augmentation (OR 1.742), immediate implantation (OR 3.509), and implant length < 10 mm (OR 2.972), were said to possess risk factors conducive to early survival rates. Conclusions The early survival rate of implants in our cohort exceeded 96%, with risk factors including age, tooth position, bone quality, implant length, bone augmentation surgery, and immediate implantation. When the above factors coexist, implant placement should be treated carefully.

A zygomatic bone study using virtual dental implant planning software

This study evaluated the anatomical factors that influence the virtual planning of zygomatic implants by using cone beam computerized tomography (CBCT) scans. CBCT scans of 268 maxilla edentulous patients were transferred to a specialized implant planning software (Galaxis, Sirona) for the following measurements: maxillo-sinus concavity size (small, medium, and large), Zygoma width, implant insertion angle, implant length, and implant apical anchorage. Concavity sizes found were as follows: 34.95% small, 52.30% medium, and 7.35% large. The mean insertion angle was 43.2 degrees and the average implant apical anchorage was 9.1mm. The most frequent implant length was 40mm. Significant differences were found when the different types of concavities in relation to the installation angle, the distance of the apical portion of the implant in contact with the zygomatic bone and the lateral-lateral thickness of the zygomatic bone were compared (p&lt;0.001). Medium-sized maxillary sinus concavity presented greater apical anchorage of the implant (9.7mm) and was the most frequent type (52.30%). The zygomatic bone is a viable site for zygomatic fixtures and the use of specialized implant planning software is an important tool to achieve predictable outcomes for zygomatic implants and allows good visualization of the implant-anatomical structures relation.