Maria Paola Cristalli

Short Dental Implants: A Systematic Review

Growing evidence has suggested the utility of short dental implants for oral reconstructive procedures in clinical situations of limited vertical bone height. The aim of this review was to systematically evaluate clinical studies of implants < 10 mm in length, to determine short implant-supported prosthesis success in the atrophic jaw. Implant survival, incidence of biological and biomechanical complications, and radiographic peri-implant marginal bone loss were evaluated. Screening of eligible studies, quality assessment, and data extraction were conducted by two reviewers independently. Meta-analyses were performed by the pooling of survival data by implant surface, surgical technique, implant location, type of edentulism, and prosthetic restoration. Two randomized controlled trials and 14 observational studies were selected and analyzed for data extraction. In total, 6193 short-implants were investigated from 3848 participants. The observational period was 3.2 ± 1.7 yrs (mean ± SD). The cumulative survival rate (CSR) was 99.1% (95%CI: 98.8-99.4). The biological success rate was 98.8% (95%CI: 97.8-99.8), and the biomechanical success rate was 99.9% (95%CI: 99.4-100.0). A higher CSR was reported for rough-surfaced implants. The provision of short implant–supported prostheses in patients with atrophic alveolar ridges appears to be a successful treatment option in the short term; however, more scientific evidence is needed for the long term.

Peri-implant marginal bone level: a systematic review and meta-analysis of studies comparing platform switching versus conventionally restored implants

AIM To systematically review the literature to compare implant survival (IS) and marginal bone loss (MBL) around platform-switched (PS) versus conventionally restored platform-matching dental implants. MATERIAL AND METHODS Randomized, controlled human clinical trials (RCTs) comparing IS and MBL in PS and conventionally restored implants, with 12 months of follow-up and at least 10 implants were identified through electronic and manual search. Review and meta-analysis were performed according to PRISMA statement. Risk ratio (RR) for implant failure and mean difference (MD) for MBL, with 95% confidence interval (CI) were calculated. Sources of heterogeneity among studies were also investigated by subgroup analyses. RESULTS Ten RCTs involving 435 subjects and 993 implants contributed to this review. The cumulative estimated implant success rate revealed no statistically significant difference between the two groups. At a patient level, a smaller amount of MBL [MD -0.55 mm, 95%CI (-0.86; -0.24), p = 0.0006] was noted around PS implants. Subgroup analyses performed at implant level suggested less MBL when platform switching showed a larger mismatching. CONCLUSION PS technique appeared to be useful in limiting bone resorption. Nevertheless, these data should be interpreted cautiously as significant heterogeneity and possible publication bias were noted. Further research is needed to identify the factors most associated with successful outcomes.

Micro‐CT and PET analysis of bone regeneration induced by biodegradable scaffolds as carriers for dental pulp stem cells in a rat model of calvarial “critical size” defect: Preliminary data

Bone regeneration strategies in dentistry utilize biodegradable scaffolds seeded with stem cells able to induce bone formation. However, data on regeneration capacity of these tissue engineering constructs are still deficient. In this study micro-Computed tomography (micro-CT) and positron emission tomography (PET) analyses were used to investigate bone regeneration induced by two scaffolds [Granular deproteinized bovine bone (GDPB) and Beta-tricalcium phosphate (β-TCP)] used alone or in combination with dental pulp stem cells (DPSC) in a tissue engineered construct implanted in a rat critical calvarial defect. Bone mineral density (BMD) and standard uptake value (SUV) of tracer incorporation were measured after 2, 4, 8, and 12 weeks post-implant. The results showed that: (1) GDPB implants were mostly well positioned, as compared to ß-TCP; (2) GDPB induced higher BMD and SUV values within the cranial defect as compared to ß-TCP, either alone or in combination with stem cells; (3) addition of DPSC to the grafts did not significantly induce an increase in BMD and SUV values as compared to the scaffolds grafted alone, although a small tendency to increase was observed. Thus our study demonstrates that GDPB, when used to fill critical calvarial defects, induces a greater percentage of bone formation as compared to ß-TCP. Moreover, this study shows that addition of DPSC to pre-wetted scaffolds has the potential to ameliorate bone regeneration process, although the set of optimal conditions requires further investigation.

A comparative morphometric analysis of biodegradable scaffolds as carriers for dental pulp and periosteal stem cells in a model of bone regeneration.

AbstractBone regeneration and bone fixation strategies in dentistry utilize scaffolds containing regenerating-competent cells as a replacement of the missing bone portions and gradually replaced by autologous tissues. Mesenchymal stem cells represent an ideal cell population for scaffold-based tissue engineering. Among them, dental pulp stem cells (DPSCs) and periosteal stem cells (PeSCs) have the potential to differentiate into a variety of cell types including osteocytes, suggesting that they can be used with this purpose. However, data on bone regeneration properties of these types of cells in scaffold-based tissue engineering are yet insufficient.In this study, we evaluated temporal dynamic bone regeneration (measured as a percentage of bone volume on the total area of the defect) induced by DPSCs or PeSCs when seeded with different scaffolds to fill critical calvarial defects in SCID Beige nude mice. Two commercially available scaffolds (granular deproteinized bovine bone with 10% porcine collagen and granular &bgr;;-tricalcium phosphate) and one not yet introduced on the market (a sponge of agarose and nanohydroxyapatite) were used. The results showed that tissue-engineered constructs did not significantly improve bone-induced regeneration process when compared with the effect of scaffolds alone. In addition, the data also showed that the regeneration induced by &bgr;;-tricalcium phosphate alone was higher after 8 weeks than that of scaffold seeded with the 2 stem cell lines. Altogether these findings suggest that further studies are needed to evaluate the potential of DPSCs and PeSCs in tissue construct and identify the appropriate conditions to generate bone tissue in critical-size defects.

Influence of endodontic treatment on systemic oxidative stress.

Introduction: An increased production of oxidizing species related to reactive oral diseases, such as chronic apical periodontitis, could have systemic implications such as an increase in cardiovascular morbidity. Based on this consideration, we conducted a prospective study to assess whether subjects affected by chronic periodontitis presented with higher values of oxidative stress than reference values before endodontic treatment, and whether endodontic treatment can reduce the oxidative imbalance and bring it back to normal in these subjects. Materials and methods: The authors recruited 2 groups of patients from private studies and dental clinics: these patients were recruited randomly. The oxidative balance in both patients with chronic apical periodontitis (CAP) and healthy control patients was determined by measuring the oxidant status, using an identification of the reactive oxygen metabolites (d-ROMs) test, while the antioxidant status in these patients was determined using a biological antioxidant potential (BAP) test. Both these tests were carried on plasma samples taken from enrolled patients. Values were measured both before the endodontic treatment of the patients with chronic apical periodontitis, and 30 and 90 days after treatment, and compared to those obtained from healthy control patients. Results: It was found that, on recruitment, the patients with chronic apical periodontitis exhibited significantly higher levels of oxidative stress than control patients, as determined by the d-ROMs and BAP tests. Furthermore, the d-ROMs test values were shown to decrease and the BAP test values to increase over time in patients with chronic apical periodontitis following endodontic therapy. As the levels of oxidative stress in these patients tended to reduce and return to normal by 90 days following treatment. Conclusions: This study has demonstrated a positive association between chronic apical periodontitis and oxidative stress. Subjects affected by chronic apical periodontitis are exposed to a condition of oxidative stress, which is extremely dangerous to general health. Moreover, one can infer from these findings that through proper endodontic therapy, a good oxidative balance can be restored, thereby avoiding the risk of contracting the abovementioned diseases.

The Role of the Template in Prosthetically Guided Implantology

In prosthetically guided implantology, where ideal placement of implants is determined by the definitive restoration, the use of a radiographic/surgical template plays an essential role. This article describes how to fabricate a radiographic/surgical template to be used for radiographic diagnosis of the selected implant sites and as a guide during surgery for the insertion of the implant with correct angulation.

LANGERHANS CELL HISTIOCYTOSIS: ORAL/PERIODONTAL INVOLVEMENT IN ADULT PATIENTS

OBJECTIVE Langerhans cell histiocytosis (LCH) is a clonal proliferative multisystem disease. Although bone and mucosae have been classified as non-risk organs, their involvement may increase the risk of disease progression. Oral and periodontal lesions are burdened with a significant impairment of quality of life for associated signs, symptoms and loss of function. Most of information regards paediatric disease; the disease in adults has received limited attention. SUBJECTS AND METHODS A total of 31 adult patients affected by immuno-histopathology confirmed LCH have been prospectively examined; attention was paid to the occurrence and characterization of oral lesions. RESULTS Twelve patients developed oral lesions. Posterior regions of jawbones were always affected; the involvement of anterior regions was not constant. Unifocal oral involvement was significantly associated with multisystemic disease while multifocal lesions were associated with unisystemic disease. Oral disease presented with soft tissue ulcers (50% of cases), gingival bleeding (66.7%), pain (83.4%), periodontal damage (50%), tooth mobility (16.7%), non-healing extraction socket (8.3%); 41.6% of patients complained of negative outcomes on quality of life. Oral lesions were easily handled with local measures. CONCLUSIONS Posterior regions require attention; single oral lesions may be part of multisystemic disease; oral and periodontal lesions may be early signs of disease reactivation.

Immediate loading of post-extractive single-tooth implants: a 1-year prospective study.

PURPOSE The aim of this prospective clinical trial was to assess clinical, radiological, and esthetic outcomes of immediate-loaded post-extractive implants after 1 year of follow-up. MATERIALS AND METHODS Twenty-four consecutive patients (15 females and nine males) with a mean age of 47.27 years (range 35-65) requiring single-tooth extraction in the maxillary or mandibular anterior or premolar areas were enrolled. Twenty-five NobelActive implants (Nobel Biocare, Göteborg, Sweden) were placed and loaded immediately after tooth extraction. The definitive prosthetic restoration was delivered 6 months later. Clinical parameters, marginal bone loss, as well as, pink and white esthetic scores (PES and WES) were evaluated at 3, 6, and 12 months after implant placement. RESULTS After 12-month follow-up period, a success rate of 91.67% was reported: Two of the 25 initially placed implants were lost after 4 weeks due to lack of osseointegration. The mean marginal bone loss after 1-year follow-up was 0.383 (SD ± 0.749) at mesial site and 0.278 (SD ± 0.595) at distal site. No statistically significant changes in the full-mouth plaque score (FMPS) and in the full-mouth bleeding score (FMBS) were observed from baseline to 12 months. The mean total PES/WES was 17.13 ± 1.91 (range: 13-20). None of 23 implants had an overall score <12 (threshold of clinical acceptability). CONCLUSION Within the limitations of the present study, when careful patient selection and strict clinical protocol are observed, the immediate placement and loading of a single NobelActive(™) implant in a fresh extraction socket may be considered a valuable and predictable option in terms of implant success as well as hard and soft tissues stability.

Survival Analysis of Implant in Patients With Diabetes Mellitus: A Systematic Review.

Aim:To determine the survival trend of dental implants after functional loading for ≥1 year in diabetic patients. Material and Methods:An electronic search of the Cochrane Oral Health Groups Trials Register, Medline and Embase, plus a manual search up to December 2015 was performed. Studies assessing the survival rate of dental implants in patients with a diagnosis of diabetes mellitus were considered eligible. Screening of studies, quality assessment, and data extraction were conducted independently by 2 reviewers. Life-table analysis and Kaplan–Meier survival curves were used to evaluate implant survival and to plot the cumulative survival rate and cumulative hazard ratio. Results:Seven studies, including 1142 implants were identified. The cumulative survival rate was 0.96 ± 0.10 before loading, 0.93 ± 0.10 and 0.91 ± 0.10 at 1 year, and at the end of the follow-up period, respectively. The hazard ratio was 4% during the period of osseointegration, 3% during the first year of loading, and remained constant over the 6-year follow-up. Conclusions:Patients with diabetes mellitus showed an increasing trend of implant failure during the period of osseointegration and the first year of loading.

Comparison of Conventional Methods and Laser-Assisted Rapid Prototyping for Manufacturing Fixed Dental Prostheses: An In Vitro Study

This study assessed whether there are differences in marginal fit between laser-fusion and conventional techniques to produce fixed dental prostheses (FDPs). A master steel die with 2 abutments was produced to receive a posterior 4-unit FDPs and single copings. These experimental models were divided into three groups (n = 20/group) manufactured: group 1, Ni-Cr alloy, with a lost-wax casting technique; group 2, Co-Cr alloy, with selective laser melting (SLM); and group 3, yttria-tetragonal zirconia polycrystal (Y-TZP), with a milling system. All specimens were cut along the longitudinal axis and their adaptation was measured at the marginal and shoulder areas on the right and left sides of each abutment. Measurements were made using a stereomicroscope (×60 magnification) and a scanning electron microscope (×800 magnification). The data were analyzed using one-way analysis of variance and the Bonferroni post hoc test, with a significance cutoff of 5%. Significant differences (P < 0.05) were observed between group 3 and the other groups. The marginal opening was smallest with Co-Cr alloy substructures, while the shoulder opening was smallest with Ni-Cr alloy substructures. Within the limitations of this study, the marginal fit of an FDP is better with rapid prototyping (RP) via SLM than conventional manufacturing systems.