Luca Gobbato

Graphene based scaffolds effects on stem cells commitment

Graphene is a flat monolayer of carbon atoms, arranged in a two-dimensional hexagonal structure, with extraordinary electrical, thermal, and physical properties. Moreover, the molecular structure of graphene can be chemically modified with molecules of interest to promote the development of high-performance devices. Although carbon derivatives have been extensively employed in industry and electronics, their use in regenerative medicine is still in an early phase. Study prove that graphene is highly biocompatible, has low toxicity and a large dosage loading capacity. This review describes the ability of graphene and its related materials to induce stem cells differentiation into osteogenic, neuronal, and adipogenic lineages.

The effect of keratinized mucosa width on peri-implant health: a systematic review.

PURPOSE The aim of this systematic review was to investigate the effect of keratinized mucosa width (KMW) on clinical parameters of peri-implant health and stability. MATERIALS AND METHODS Two independent reviewers conducted a comprehensive search to identify studies on human subjects reporting KMW as a bivariate factor (≥ 2 mm and < 2 mm), along with mean pocket depth (PD), bleeding on probing (BOP), modified Bleeding Index (mBI), Gingival Index (GI), Plaque Index (PI), modified PI (mPI), and implant survival with a minimum follow-up of 6 months after implant loading. Eight studies were included in the systematic review and seven in the metaanalyses to ascertain summary effects for differences in the aforementioned parameters among groups of KMW. RESULTS Pooled analyses showed that GI, PI, and mPI were significantly higher in the group with KMW of < 2 mm, while mBI was also higher but only marginally significant. In contrast, PD was not significantly different between the two groups. Differences in BOP and implant survival rate could not be analyzed because of limited data availability. Heterogeneity was highly significant among the pooled studies for all investigated variables. CONCLUSION Reduced KMW around implants appears to be associated with clinical parameters indicative of inflammation and poor oral hygiene. However, based on the selected evidence, the predictive value of KMW is limited.

Three-Dimensional Volume Change of Grafted Bone in the Maxillary Sinus

PURPOSE The purpose of this study was to evaluate the three-dimensional radiographic changes of 100% anorganic bovine bone xenograft volume in a grafted maxillary sinus, based on a computerized analysis of cone-beam computed tomography (CBCT) scan. MATERIALS AND METHODS A maxillary sinus augmentation procedure done with a lateral approach using 100% anorganic bovine bone was performed in 20 patients. A CBCT scan of the grafted area was taken immediately after the procedure (T1) and 8 to 9 months later (T2). CBCT scan data were analyzed with image processing software to evaluate differences in the volume of grafted material between T1 and T2. Residual ridge height and width were also measured at T1. RESULTS The mean residual bone height and width at the implant sites was 4.40±0.87 mm and 7.9±2.22 mm, respectively. The mean graft volume was 1,432±539 mm³ and 1,287±498 mm³ at T1 and T2, respectively. A significant difference in graft volume was found between T1 and T2 data by paired t test (P=.01). The mean ratio between the volume at T2 and the volume at T1 was 0.90±0.12, meaning a graft volume contraction of 10%. CONCLUSION Within the limits of the present investigation, good stability of anorganic bovine bone graft volume up to 8 months after the grafting procedure was demonstrated. Three-dimensional computed tomographic volumetric assessment seems to be a promising approach to quantify long-term changes in the regenerated area.

Maintaining interimplant crestal bone height via a combined platform-switched, Laser-Lok implant/abutment system: a proof-of-principle canine study.

Interimplant papillae are critical for achieving esthetic implant-supported restorations in the maxillary esthetic zone. Stable papillary anatomy, however, depends upon a stable volume of underlying crestal bone for support. Multiple studies have documented a critical interimplant distance of 3 mm under which crestal bone resorption occurs. This preclinical proof-of-principle canine study examines a novel implant-abutment system design, combining platform switching with precisely configured laser-ablated abutment and implant microgrooves to maintain interimplant crestal bone at interimplant distances of 2 and 4 mm. Results of this initial preclinical study suggest that it is possible through precise implant/abutment design modifications to place adjacent implants at distances of 2 to 4 mm without inducing subpapillary crestal bone loss.

Early bone healing around 2 different experimental, HA grit-blasted, and dual acid-etched titanium implant surfaces. A pilot study in rabbits.

Purpose:To compare early bone healing around different experimental titanium implant surfaces and to evaluate the role of a calcium phosphate–coated implant surface because it relates to bone-implant contact (BIC). Methods:An experimental hydroxyapatite (HA) grit-blasted and dual acid-etched titanium surface (BAE-1) was compared to an experimental HA grit-blasted and dual acid-etched surface treated with nanometer-scale crystals of HA (BAE-2). Both experimental implant surfaces were implanted onto the tibias of 4 New Zealand white rabbits. The animals were killed at 1,6, 21, and 90 days after the implant surgery. Descriptive histology was performed at the healing responses of both implant surfaces. Quantitative morphology assessment provided measurements of BIC, number of bone multicellular units (BMUs), average penetration of BMUs, and maximum penetration of BMUs that were manually made using imaging computer software. Result:The overall BIC for the BAE-2 implant was higher than that for the BAE-1 implant at 21 days of healing. However, there was no significant difference at 90 days of healing. Conclusion:It is concluded from this animal pilot study that the bioactive BAE-2 implant surface provided a better BIC with healthy bone remodeling at 21 days of healing

Periodontal response to two different subgingival restorative margin designs: a 12-month randomized clinical trial

ObjectivesSubgingival margin placement is sometimes required due to different reasons and is often associated with adverse periodontal reactions. The purpose of this study was to determine if a single restoration with subgingival margin on a tooth, in the maxillary anterior zone, would affect its periodontal soft tissue parameters, and whether or not a deep chamfer preparation has a different influence in the periodontium when compared to a feather edge preparation.Material and methodsPlaque and gingival indexes, periodontal probing depth, bleeding on probing, and patient’s biotype were registered. One hundred six teeth were prepared with a deep chamfer, while 94 were prepared with a feather edge finishing line. Twelve months after the restoration delivery, the same parameters were evaluated. Repeated measure one-way analysis of variance (ANOVA) (α = 0.05) was used.ResultsA statistically significant difference between the baseline and the 12-month follow-up is present in regard to plaque index, gingival index, and periodontal probing depth, but no statistically significant difference between chamfer and feather edge finishing lines. There is a statistically significant difference between the baseline and the 12-month follow-up in regard to bleeding on probing. Feather edge preparation presents significantly more bleeding on probing and less gingival recession than the chamfer.ConclusionsSubgingival margins do influence the periodontal soft tissue response. Statistically significant difference exists between feather edge and chamfer finishing lines in regard to bleeding on probing and gingival recession.Clinical relevanceSubgingival margins should be carefully selected, especially when feather edge finishing line is utilized.

Pulsed electromagnetic fields for postoperative pain: a randomized controlled clinical trial in patients undergoing mandibular third molar extraction.

OBJECTIVES The clinical efficacy of a wearable pulsed electromagnetic field (PEMF) therapy device was assessed in terms of pain and quality of healing after tooth extraction. STUDY DESIGN This randomized, parallel design, placebo-controlled study involved 120 patients undergoing unilateral mandibular third molar extraction and assigned to three groups after surgery. Test and placebo patients wore enabled or disabled PEMF devices, respectively, and controls wore no device. Patients recorded pain (on the visual analog scale) and analgesic use for a week, after which healing complications were assessed. RESULTS Test patients had only slightly lower visual analog scale scores and analgesic use, but significantly fewer cases of dehiscence than placebo patients. CONCLUSIONS PEMF therapy delivered by a wearable device improved soft tissue healing and may be a useful adjunct for pain management after oral surgery.

Clinical Periodontal Response to Anterior All-Ceramic Crowns with Either Chamfer or Feather-edge Subgingival Tooth Preparations: Six-Month Results and Patient Perception.

Subgingival margins are often required for biologic, mechanical, or esthetic reasons. Several investigations have demonstrated that their use is associated with adverse periodontal reactions, such as inflammation or recession. The purpose of this prospective randomized clinical study was to determine if two different subgingival margin designs influence the periodontal parameters and patient perception. Deep chamfer and feather-edge preparations were compared on 58 patients with 6 months follow-up. Statistically significant differences were present for bleeding on probing, gingival recession, and patient satisfaction. Feather-edge preparation was associated with increased bleeding on probing and deep chamfer with increased recession; improved patient comfort was registered with chamfer margin design. Subgingival margins are technique sensitive, especially when feather-edge design is selected. This margin design may facilitate soft tissue stability but can expose the patient to an increased risk of gingival inflammation.

Results of Computer-Guided Bone Block Harvesting from the Mandible: A Case Series

Autogenous bone harvesting is a well-documented surgical procedure. Autogenous mandibular bone harvesting carries a risk of anatomical structural damage because the surgeon has no three-dimensional (3D) control of the osteotomy planes. The aim of this case series was to describe the results of mandibular bone block harvesting applying computer-guided surgery. A sample of 13 partially dentate patients presenting bone deficiencies in the horizontal and/or vertical plane were selected for autogenous mandibular bone block graft. The bone block dimension was planned through a computer-aided design (CAD) process, defining ideal bone osteotomy planes to avoid damage to anatomical structures (nerves, teeth roots, etc) and to generate a surgical guide that imposed the 3D working direction to the bone-cutting instrument. The bone block dimension was always related to the defect dimension to be compensated. A total of 13 mandibular bone blocks were harvested to treat 16 alveolar defects (9 vertical and 7 horizontal). The mean planned mesiodistal dimension of the bone block was 24.8 ± 7.3 mm, the mean height was 8 ± 1 mm, and the mean thickness was 4 ± 2 mm. None of the treated patients experienced neurologic alteration of their alveolar nerve function. The preliminary data from this case series suggested that computer-guided bone harvesting could be a concrete opportunity for clinicians to obtain an appropriate volume of autogenous bone in a safe manner.

Human Histologic Evaluation of Root Coverage Obtained with Connective Tissue Graft Over a Compomer Restoration

This investigation was designed to evaluate the histologic healing pattern of two Miller Class III recession defects associated with noncarious cervical lesions (NCCLs) treated with a connective tissue graft (CTG) and coronally advance flap (CAF). One patient presenting with two teeth predetermined to be surgically extracted was enrolled and consented to treatment. One month after phase I treatment, a full-thickness flap was reflected and the NCCLs treated with a compomer restoration; at the same time, a CTG was harvested from the palate and positioned over the compomer restoration. The flap was then coronally repositioned. After 4 months of healing, an en bloc biopsy extraction of the two teeth was executed. The teeth were analyzed histologically to assess the periodontal wound healing. A long junctional epithelial attachment was noted throughout the major portion of the restored surface. Only minimal signs of connective adhesion and new bone formation could be seen in the apical portion of the restored area, without signs of root resorption or ankylosis. This report provides evidence that the presence of a compomer restoration allowed the formation of a long juctional epithelium after CTG and CAF treatment.