Framework Fracture of Zirconia Supported Full Arch Implant Rehabilitation: A Retrospective Evaluation of Cantilever Length and Distal Cross-Sectional Connection Area in 140 Patients Over an Up-To-7 Year Follow-Up Period.

PURPOSE: To evaluate the relationship between different dimensional parameters in implant-supported monolithic zirconia fixed complete dental prostheses (IFCDPs) and the incidence of framework fracture in a large sample of cases in vivo. MATERIALS AND METHODS: This retrospective observational study evaluated all patients rehabilitated with screw-retained zirconia IFCDPs between January 2013 and April 2019 at a private practice. The minimum follow-up period was 1 year after occlusal loading. Fractures were classified as: type I-fractures that happened between but not involving the two most posterior screw-access openings (SAOs) and type II-fractures of the distal cantilever. Cantilever length, distal connector cross-sectional area, and screw access opening length were measured using data obtained from digital scans. Logistic regression was performed to evaluate the relationship between types I and II fractures and the independent variables (dimensional parameters). Using the receiver operating characteristic curves, two parameters were identified to be useful for establishing a cut-off and predicting type II fractures. RESULTS: A total of 180 prostheses delivered to 140 patients were analyzed. Five implants failed in three patients: three before delivery of the definitive prostheses and two after. Ten prostheses failed (5.6% prosthetic failure rate): 2 because of implant failures, and 8 because of framework fractures. Five fractures were classified as type I and three as type II. Significant associations were found between cantilever length and type I fractures (Wald = 5.772, df = 1, p = 0.016), distal connector cross-sectional area and type II fractures (Wald = 3.806, df = 1, p = 0.051), and cantilever length and the total number of fractures (Wald = 6.117, df = 1, p = 0.013). CONCLUSION: Zirconia IFCDPs may be reliable medium-term solutions if some dimensional parameters are followed. The ratios between the cantilever length and cross-sectional connector area should be <0.51, while the ratio between the cantilever length and screw access opening length should be <1.48.

Immediate implant placement and loading in the esthetic area when the buccal socket wall is significantly damaged.

OBJECTIVES: Recent clinical recommendations contraindicate immediate implant placement when the socket buccal bone plate is significantly damaged. The connective tissue graft (CTG) is increasingly being used in implant therapy and can replace periodontal defects lacking bone wall in periodontal regenerative surgery. Therefore, CTG could be used to allow immediate implant placement and loading even when the buccal socket wall is damaged, facilitating graft material stability. CLINICAL CONSIDERATIONS: In the first case, deep bone dehiscence was caused by a vertical root fracture. In the second case, a big bone fenestration was caused by a chronic endodontic periapical lesion. Both cases were treated with immediate implant placement and loading. A buccal CTG was used to compensate for the lack of bone and allow stabilization of the particulate xenograft in the gap between the implant and the damaged buccal socket wall. In both cases, a provisional screw-retained crown was immediately delivered, and the definitive layered zirconia crown was delivered after 3 months. Esthetic results and patient satisfaction monitored for 1 year after loading proved to be encouraging. CONCLUSIONS: Although further investigations with longer follow-up are required, the approach is likely to yield good results after 1 year of loading. CLINICAL SIGNIFICANCE: The purpose of this report is to show a surgical approach that seems to be able to overcome the contraindication of the quoted consensus report, which allows for good esthetic results and patient satisfaction even when the buccal bone wall of the extraction socket has been more than 50% compromised, allowing treatment time and cost reduction.

Three-Year Evaluation of the Influence of Implant Surfaces on Implant Failure and Peri-implantitis: A Double-Blind Randomized Controlled Trial with Split-Mouth Design.

PURPOSE: To compare the onset of peri-implantitis, incidence of failure, and peri-implant marginal bone level changes between implants with a roughened surface and those with a machined/turned surface. MATERIALS AND METHODS: All patients needing two dental implants of the same size on the left and right sides of the same arch, and not scheduled for immediate loading, were enrolled between October 2012 and February 2016. The patients were randomly allocated either to Nobel Biocare MKIII or Sweden & Martina Outlink2. Rough-surface implants and machined-surface implants were used from each company. After the preparation of two identical implant sites, each implant (rough or machined of the same group) was randomly allocated to the right and left sides of the same patient, following a split-mouth design. Outcome measures were peri-implantitis onset, incidence of failure, and peri-implant marginal bone level changes. Patients were followed up for 3 years after loading. RESULTS: One hundred fourteen patients were enrolled and treated; nine patients dropped out. Following an intent-to-treat analysis to avoid overestimation, proportions are given related to the initial number of 114 patients. Peri-implantitis incidence was 4.39% for machined implants (5/114), 0.88% for rough implants (1/114), 1.75% in the Nobel Biocare group (2 cases), and 3.51% in the Sweden & Martina group (4 cases). The failure rate was 1.75% in machined implants (2/114), 0.88% in rough implants (1/114), 0.98% in the Nobel Biocare group (1/114), and 1.85% in the Sweden & Martina group (1/114). No statistically significant differences in marginal bone loss were found comparing different surfaces, while marginal bone loss was significantly lower in Nobel Biocare than in Sweden & Martina implants. CONCLUSION: Based on the results of this study, no significant differences can be demonstrated in either peri-implantitis or failure rate or in marginal bone loss between rough and machined implants. Marginal bone loss was significantly worse in machined-surface Sweden & Martina than in rough-surface Nobel Biocare implants.

Is the postoperative discomfort after connective tissue harvesting from the palate influenced by the use of a bipolar coagulator? A randomized controlled trial.

OBJECTIVES: This study aimed to determine the effect of the use of a bipolar coagulator on postoperative pain and complications when used during connective tissue harvesting from the palate. MATERIAL AND METHODS: A randomized controlled clinical trial was conducted with 57 sequential patients requiring a connective tissue graft for periodontal or implant surgery. All samples were harvested superficially and de-epithelized outside the mouth. The patients were randomly allocated to two groups: in one group, the bipolar coagulator was used before suturing to control bleeding, and in the other group, the coagulator was not used. The surgeon was unaware of the randomization until the end of the harvesting phase. Self-reported maximum pain, number of painkillers used, bleeding events, emergency visits at the clinic were recorded 7 days after surgery. RESULTS: Fifty patients were randomized and treated (seven were excluded for different reasons). The mean harvested area was 75.24 mm2 (SD, 33.96), and the mean thickness of the samples was 2.47 mm (SD, 0.75). The mean self-reported pain value on the visual analog scale was 3.37 (SD, 2.30), and the mean number of pain medications used was 7.1 (SD, 6.60). Seven patients made an emergency visit each, and 17 delayed bleeding events were reported by 15 patients. No statistically significant differences were reported in postoperative pain, postoperative bleeding, and emergency visit to the clinic between the groups that did and did not use the bipolar coagulator. When smoking habits were taken into consideration, the number of pain medications was higher among male smokers and older smokers than among male non-smokers and younger smokers. This study was not able to find a relationship between harvested sample dimension or thickness and postoperative discomfort. CONCLUSIONS: The bipolar coagulator can be used during connective tissue harvesting from the palate to control bleeding without influencing postoperative pain.

Jawbone remodeling: a conceptual study based on Synchrotron High-resolution Tomography.

One of the most important aspects of bone remodeling is the constant turnover mainly driven by the mechanical loading stimulus. The remodeling process produces changes not only in the bone microarchitecture but also in the density distribution of the mineralized matrix - i.e. in calcium concentrations- and in the osteocyte lacunar network. Synchrotron radiation-based X-ray microtomography (microCT) has proven to be an efficient technique, capable to achieve the analysis of 3D bone architecture and of local mineralization at different hierarchical length scales, including the imaging of the lacuno-canalicular network. In the present study, we used microCT within a conceptual study of jawbone remodeling, demonstratively focusing the investigation in two critical contexts, namely in the peri-dental and the peri-implant tissues. The microCT analysis showed that a relevant inhomogeneity was clearly present in both peri-dental and peri-implant biopsies, not only in terms of microarchitecture and mineralization degree, but also considering the lacunar network, i.e. size and numerical density of the osteocyte lacunae. The correlated histological results obtained on the same samples confirmed these observations, also adding information related to non-mineralized tissues. Despite its demonstrative nature, it was concluded that the proposed method was powerful in studying jawbone remodeling because it revealed a direct correlation of its rate with the lacunar density, as achieved by the analysis of the osteocyte lacunar network, and an inverse correlation with the local bone mineral density, as revealed with the Roschger approach.

Histologic and Radiographic Analysis of Nonhealing Extraction Sockets Treated with Bio-Oss Collagen After a 4-Month Healing Period: A Prospective Descriptive Study in Humans.

Healing of extraction sockets may sometimes result in formation of fibrous tissue instead of bone, even after 4 months, an occurrence that may hinder implant placement. The aim of this preliminary observational study was to histologically evaluate quality and amount of bone regeneration after treating nonhealing sockets with a bovine-derived xenograft enriched with porcine collagen (Bio-Oss Collagen, Geistlich) without barrier membranes. Biopsy specimens were collected during implant placement, 4 months after grafting. A total of 10 cases were treated and evaluated. In all cases, correct implant placement was possible and no implant failure occurred up to 6 months after loading. The histologic analysis demonstrated new bone formation in all specimens. The percentage of newly formed bone was 29.1% (SD 20.71%; range 5% to 48%). Xenograft particles in direct contact with newly formed bone were visible, and mature lamellar bone was observed in 8 cases.

Clinical and histopathologic independent prognostic factors in oral squamous cell carcinoma: a retrospective study of 334 cases.

PURPOSE: This retrospective hospital-based study reviewed and evaluated the outcome of patients with oral squamous cell carcinoma (OSCC) with the aim of identifying factors affecting the clinical course and survival rate. PATIENTS AND METHODS: Patients with a follow-up of at least 12 months were included. The data collected were statistically analyzed for the presence of factors valuable for prognosis; survival curves were processed in accordance with the Kaplan-Meier method. Differences in the expression of variables in different grading levels were investigated. Cox's proportional hazard model for Z(i) covariates (grading, age, T, N) also was calculated. RESULTS: Mean patient age was 67.7 years in women (n = 152) and 62.4 years in men (n = 182). A total of 98 patients were identified with Broder's/World Health Organization grade 1 histology, 176 with grade 2, and 55 with grade 3; 5 patients were identified as grade 4 (carcinoma in situ). Gender and risk factors seemed to be unrelated to prognosis, whereas a significant increase in mortality was seen in patients over age 70. Histological grading, tumor size, and neck involvement were related, as independent factors, in predicting survival in patients with OSCC (QM-H > 3.9). Gender, age, and risk factors had no statistical relationship with cancer histological differentiation. CONCLUSIONS: Our analysis reveals a statistically significant relationship among histological Broder's grading of malignancy, tumor size, locoregional involvement, and survival rates, underscoring the utility of tumor differentiation in predicting the clinical course and outcome of OSCC.

Esthetic treatment of alveolar ridge atrophy in the anterior maxilla via connective tissue graft performed simultaneously with implant placement: A three-case series.

OBJECTIVE: The mere osseointegration of an implant should no longer be considered a satisfactory criterion for success. Tooth extraction itself and, more importantly, possible local comorbidities such as periodontal or endodontic diseases, cause a reduction in the gingival volume of the edentulous site due to bone atrophy. This reduced volume must be treated and resolved to obtain a satisfactory esthetic result, which is an essential factor for successful implant rehabilitation. The classic approach to this problem relies on bone augmentation procedures. However, the present clinical study is aimed at showing that insufficient gingival volume may be corrected simply by resorting to soft tissue augmentation, provided that sufficient bone is present to allow implant placement. Clinical Considerations: The treatment is described of three cases characterized by considerable ridge atrophy that was caused by a simple extraction in the first case, periodontal breakdown in the second case, and radicular cyst removal in the third case. After healing, all cases presented with sufficient bone to allow implant placement, and insufficient volume was treated via soft tissue grafts during implant surgery. Esthetic results and patient satisfaction were monitored for 2 to 4 years and were very encouraging. CONCLUSION: Although the approach described in this report requires further investigation, it will likely lead to good results when used to treat a lack of pink volume in the most important esthetic area.

Evidence of earlier thyroid dysfunction in newly diagnosed oral lichen planus patients: a hint for endocrinologists.

The association between oral lichen planus (OLP) and hypothyroidism has been debated with conflicting results: some authors detected a statistically significant association between these two, while others did not confirm it. The aim of this study was to evaluate the thyroid status in patients with newly diagnosed OLP to test the null hypothesis that thyroid disease is not associated with an increased incidence of oral lesions, with a prospective case-control approach. A total of 549 patients have been evaluated, of whom 355 were female. Odds ratio (OR) and 95% confidence intervals (CIs) were obtained. Patients suffering from thyroid diseases were associated with an almost 3-fold increased odds of having OLP (OR 2.85, 95% CI: 1.65-4.94), after adjusting this analysis for age, gender, body mass index, smoking status, diabetes, hypertension and hepatitis C infection. It would be appropriate to further investigate the possible concomitance of OLP among patients with thyroid disorder; endocrinologists should be aware of this association, especially because OLP is considered a potentially malignant oral disorder.

Clinical attachment level gain and three-year maintenance of a maxillary incisor with 100% bone loss: A case report.

This case report discusses a patient suffering from chronic periodontal disease and diagnosed with a hopeless central incisor. The intention was to show the possibility of gaining new clinical attachment via regenerative surgery in a tooth with 100% bone loss around the root. Treatment of hopeless and questionable teeth in periodontal patients has become an ideological matter. On the one hand, dental implants have proved to be a reliable solution to replace lost teeth; on the other hand, newly emerging evidence suggests that successful periodontal treatment of teeth diagnosed as hopeless is possible. Here we describe surgical, orthodontic, and restorative treatments that led to clinical attachment gain and achieved clinical success over a three-year follow-up period.

Adhesive esthetic treatment of non-syndromic maxillary anterior microdontia in young high-demanding patients: a case series.

BACKGROUND: Microdontia of the maxillary anterior teeth occurs quite frequently but is poorly documented. The literature describes several treatment choices, which are often focused on an orthodontic approach rather than a restorative one. The latest trends in restorative dentistry and the new ceramic materials, such as lithium disilicate, allow clinicians to perform esthetic rehabilitations based on microinvasive approaches that are most appropriate for younger patients. SUMMARY: Four patients, all employed in the field of dentistry, presented at our dental practice complaining of diastemata between their maxillary anterior teeth. Clinical analysis showed that the six anterior teeth were smaller than normal. In this article, we describe the treatment performed in these cases using ceramic veneers. Only one case required a preparatory orthodontic intervention. The esthetic integration of the restorations was excellent, and no fractures or debondings were registered at the 2-year follow-up, resulting in a high degree of patient satisfaction. CONCLUSION: Since microdontia is a shape defect, we strongly believe that when patients ask for its correction, the treatment should focus on shape adjustments performed with mini-invasive techniques. Orthodontics may be a useful preparatory step to optimize the distribution of the teeth to be restored.

Is a high level of total cholesterol a risk factor for dental implants or bone grafting failure? A retrospective cohort study on 227 patients.

PURPOSE: This study aims to verify the effect of hypercholeresterolaemia on implant and bone augmentation failures. MATERIALS AND METHODS: A retrospective cohort study was conducted on 268 sequential patients scheduled for implant and bone augmentation surgery under conscious sedation in a private practice. Total serum cholesterol (TC) levels were assessed via blood tests before surgery. Patients were divided into two groups: TC < 200 mg/dl and TC > 200 mg/dl. A 6-month post-loading follow-up was scheduled both for implants and grafts. The outcomes considered were implant failure (removal) and graft infection/failure. The effect of cholesterol on early implant and grafting failure was investigated according to a logistic regression model. RESULTS: Two hundred and twenty-seven patients fulfilled inclusion criteria; 139 had hypercholesterolemia. The 6-month post-loading overall implant failure rate was 6.25% at patient level (2.00% at implant level). Partial or total graft infection rate was 10.2%. High TC increased by 7.48 times the odds of the grafting failure (P = 0.047; 95% CI: -0.94 to 59.23), whilst it did not modify the odds of implant failure (P = 0.749; 95% CI: 0.28 to 2.49). CONCLUSIONS: High total serum cholesterol levels tend to increase graft failure rates whilst it did not influence implant failures.

Conservative Nonsurgical Treatment of Class 4 Invasive Cervical Resorption: A Case Series.

External cervical resorption, also called invasive cervical resorption (ICR), is a pathological process difficult to diagnose that causes a progressive replacement of dentin by granulation tissue and results in complete tooth destruction. According to the literature, class 4 ICR can be expected to have success rates of 12.5% if treated. In this case series, we show nonsurgical conservative treatment of 4 patients affected by class 4 ICR. In 4 patients affected by class 4 ICRs, granulomatous tissue was orthograde removed with the help of an operating microscope and cone-beam computed tomographic imaging. The teeth were devitalized, the granulomatous tissue was mechanically removed, and the defects were filled with either mineral trioxide aggregate or Biodentine (Septodont, Saint-Maur-des-Fossés, France). After a follow-up period varying from 18 months for case 1 to 4 months for case 4, neither signs of periradicular bone rarefaction nor recurrence of resorption were observed. The teeth were asymptomatic, and conservative restorations appeared to be in excellent condition. Given the results achieved in this case series, it may be assumed that many class 4 ICRs could be successfully treated with the help of an operating microscope and cone-beam computed tomographic imaging.

Treatment of a case of serious occlusal instability associated with TMDs through a modern mini-invasive approach.

BACKGROUND: The latest trends in restorative dentistry are guided both by esthetic and mini-invasive procedures. New ceramic materials, such as lithium disilicate, allow the clinician to obtain invisible restorations with a minimum preparation thickness. SUMMARY: A young female patient presented at our practice with left temporomandibular closed locking and uncomfortable occlusal instability. After manual reduction, medical therapy, and reversible treatment with a stabilization splint, a mini-invasive lithium disilicate occlusal inferior posterior rehabilitation was conceived and performed. The esthetic integration of the onlay restorations was excellent, no fractures had occurred by the time of the 1-year follow-up, and the patient perceived the dental occlusion as comfortable. CONCLUSION: We strongly believe that a careful approach to esthetics is mandatory nowadays, including in the case of posterior teeth. New ceramic materials and the latest adhesive techniques make it possible to resort to mini-invasive and esthetic approaches, even in cases of restorations that are difficult in terms of functionality.

Single preoperative dose of prophylactic amoxicillin versus a 2-day postoperative course in dental implant surgery: A two-centre randomised controlled trial.

PURPOSE: To evaluate the difference between a single preoperative dose versus an additional two-day postoperative course of oral amoxicillin in patients undergoing conventional dental implant placement. MATERIALS AND METHODS: Two dentists in two different private practices conducted this study. One hour prior to surgery, patients had to take a single prophylactic antibiotic dose, consisting of 2 g of amoxicillin orally; after implant placement, patients were randomly allocated to two different groups: protocol A (no other antibiotic administration) and protocol B, (1 g of amoxicillin in the evening of the day of surgery and 1 g twice a day for the 2 days after). Outcome measures were prosthetic and implant failures, adverse events and early postoperative complications. Patients were followed up to 6 months after functional loading. RESULTS: Three hundred and sixty patients were randomised and treated (192 patients in one centre and 168 in the other). Five hundred and sixty-seven implants were placed. Protocol A was applied to 180 patients (278 implants) and protocol B also to 180 patients (289 implants). Data for 17 patients, 14 from protocol A and three from protocol B, were not available. No statistically significant differences were found for the reported outcomes. Two patients of protocol B experienced a prosthetic failure, losing four implants, while no prosthetic failures were reported for protocol A (P=0.4836; difference in proportions=-0.0110; 95% CI: -0.0412 to 0.0119). Five patients (3.0%) of protocol A lost five implants versus 5 patients (2.8%) who lost eight implants in protocol B (P=1.0000; difference in proportions=0.0020; 95% CI: -0.0384 to 0.0438). Three adverse events were observed in the total population, all occurring in protocol B (1.69%), with no statistically significant differences between the two groups (P=0.1199; difference in proportions=-0.0170; 95% CI: -0.0487 to 0.0059). However, one patient experienced a severe allergic reaction requiring therapy discontinuation and hospital admission. Early postoperative complications occurred in six patients of protocol A and in four patients of protocol B, with no statistically significant differences (P=0.5170; difference in proportions=0.0130; 95% CI: -0.0254 to 0.0568). CONCLUSIONS: No statistically significant differences were observed between 2 g of preoperative amoxicillin and an additional 2-day postoperative course, although adverse events were reported only in the additional 2-day postoperative group. Based on these findings, it might be sufficient to routinely administer preoperatively 2 g of amoxicillin to patients undergoing routine dental implant placement procedures rather than administering additional postoperative doses.

The connective tissue graft wall technique and enamel matrix derivative to improve root coverage and clinical attachment levels in Miller Class IV gingival recession.

The case reports in this article describe a surgical approach for improving root coverage and clinical attachment levels in Miller Class IV gingival recessions. Two gingival recessions affecting maxillary and mandibular lateral incisors associated with severe interdental hard and soft tissue loss were treated. The surgical technique consisted of a connective tissue graft (CTG) that was placed below a coronally advanced envelope flap and acted as a buccal soft tissue wall of the bony defect treated with enamel matrix derivative (EMD). No palatal/lingual flap was elevated. In the first clinical case, 6 months after surgery a ceramic veneer was placed to correct tooth extrusion and improve the overall esthetic appearance. One year after the surgery in both cases, clinically significant root coverage, increase in buccal keratinized tissue height and thickness, improvement in the position of the interdental papilla, and clinical attachment level gain were achieved. The radiographs demonstrate bone fill of the intrabony components of the defects. This report encourages a novel application of CTG plus EMD to improve both root coverage and regenerative parameters in Miller Class IV gingival recessions.

Oral pemphigoid autoantibodies preferentially target BP180 ectodomain.

Mucous membrane pemphigoid (MMP) comprises a heterogenous group of autoimmune subepithelial bullous diseases very frequently having oral involvement. Very few studies have investigated the immunological status of a subset of MMP, termed oral pemphigoid (OP), presenting with exclusive oral lesions. In this study we show that 75% of 20 OP patients without scarring phenotype possessed circulating autoantibodies against the BP180 molecule, indicating a prominent role of this protein as a target antigen in OP. Of note, the frequency of reactivity against BP180 ectodomain epitopes in OP was similar to that previously reported for MMP with cicatricial phenotype, while the lack of significant recognition of BP180 intracellular domain appears to characterize OP with respect to other diseases of the pemphigoid group. Finally, the combined use of sensitive techniques allowed the detection of circulating autoantibodies in 90% of OP patients, supporting the usefulness of this approach in the diagnosis of MMP disease.