Supportive care and antiviral treatments in primary herpetic gingivostomatitis: a systematic review.

OBJECTIVES: Herpes simplex virus 1 (HSV-1) is the main pathogen responsible for herpes infections. In 13-30% of the cases, primary HSV-1 leads to the primary herpetic gingivostomatitis (PHGS), often a self-limiting infection; however, it can limit the ability to drink/eat with, sometimes, the need for hospitalization. Multiple therapeutic methods have been proposed. This systematic review aims to collect and critically appraise the available evidence about the clinical management of PHGS. MATERIALS AND METHODS: Literature search including three databases (PubMed, Scopus, Embase), study design, and data analysis were performed following PRISMA guidelines, according to the PICO tool (PROSPERO n° CRD42023391386). Risk of bias was assessed with RoB 2 and ROBINS-I. RESULTS: Five studies on a total of 364 patients (average age: 7.6 years) were identified. The treatment regimens were summarized in acyclovir; acyclovir + honey; fluids and analgesic; maalox + diphenhydramine; lidocaine; chlorhexidine (CHX); CHX + ialuronic acid; CHX + Mucosyte®; antimicrobial photodynamic therapy (aPDT); topical antiviral; topical antiviral + aPDT; and others. CONCLUSIONS: Although PHGS is a disease with a high worldwide prevalence, the lack of consensus about therapeutic management indicates gaps in existing evidence. Most of the proposed treatment consists in symptomatic drugs with empiric regimens which are ineffective for the viral replication. The main limit to realize randomized clinical trial is due to the rapid onset and remission of the disease. In fact, the diagnostic delay, estimated in 72 h, decreases the effectiveness of any antiviral drugs. CLINICAL RELEVANCE: Out of the five studies included in this systematic review, only one was able to provide some weak evidence that ACV is an effective treatment, improving healing of oral lesions and reducing duration of symptoms.

Regeneration of dentin-pulp complex: Effect of calcium-based materials on hDPSCs differentiation and gene expression.

OBJECTIVE: Dentin-pulp complex is object of interest in the regenerative endodontic field as well as the natural function of human dental pulp stem cells (hDPSCs) that may differentiate into specific cells able to repair and/or regenerate both hard and soft dental structures. The aim of the present study was to evaluate the capacity of hDPSCs to differentiate in odontoblastic-like cells by evaluating the expression of specific odontogenic-related genes and to prove the ability of treatment with calcium-based materials such as calcium carbonate (CaCO3), calcium hydroxide (Ca(OH)2), and mineral trioxide aggregate (MTA). METHODS: hDPSCs were obtained and isolated from a third molar of a young patient. Odontogenic-related gene expression was assessed unti1 28 days of culture as well as alkaline phosphatase activity (ALP). hDPSCs were cultured in odontoblastic-induction medium used as control, and in presence of different concentrations of CaCO3, Ca(OH)2, and MTA. RESULTS: The results demonstrated an upregulation in odontoblastic cell-related genes, in particular of the early differentiation marker known as matrix extracellular phosphoglycoprotein (MEPE), as well as increased ALP activity and the presence of calcium deposits, mainly by stimulation with calcium derivatives. In this regard, treatment of pulp tissue with CaCO3, Ca(OH)2 and even better with MTA seemed to be effective for dentinogenesis. SIGNIFICANCE: The ease of isolation of hDPSCs from discarded or extracted teeth offers a promising source of autologous cells that may be applied for regenerative purpose in combination with selected bioactive materials. However, further investigations should be conducted to confirm the obtained results.

The Predictability of Transverse Changes in Patients Treated with Clear Aligners.

Arch expansion might be used to correct buccal corridors, improve smile aesthetics, resolve dental cross bite, and gain space to resolve crowding. In clear aligner treatment, the predictability of the expansion is still unclear. The purpose of this study was to evaluate the predictability of dentoalveolar expansion and molar inclination with clear aligners. In the study, 30 adult patients (27 ± 6.1 years old) treated with clear aligners were selected (treatment time: 8.8 ± 2.2 months). The upper and lower arch transverse diameters were measured for canines, first and second premolars, and first molars on two different sides (gingival margins and cusp tips); moreover, molar inclination was measured. A paired t-test and Wilcoxon test were used to compare prescription (planned movement) and achieved movement. In all cases, except for molar inclination, a statistically significant difference was found between achieved movement and prescription (p < 0.05). Our findings showed a total accuracy of 64% for the lower arch, 67% at the cusp level, and 59% at the gingival level, with a total accuracy of 67% for the upper arch, 71% at the cusp level, and 60% at the gingival level. The mean accuracy for molar inclination was 40%. Average expansion was greater at cusps of canines than for premolars, and it was lowest for molars. The expansion achieved with aligners is mainly due to the tipping of the crown rather than bodily movement of the tooth. The virtual plan overestimates the expansion of the teeth; thus, it is reasonable to plan an overcorrection when the arches are highly contracted.

Periapical Healing following Root Canal Treatment Using Different Endodontic Sealers: A Systematic Review.

The healing of the periapical tissues is crucial to the success of root canal treatment. The review studies effectively examine various endodontic root canal sealants in terms of periapical healing. This systematic review was formulated following the PRISMA 2020 guidelines and registered in the international prospective register of systematic reviews (PROSPERO) number-CRD42021239192. To find relevant articles, PubMed Central and Medline databases (until February 2022) were searched. Studies that evaluated healing following the application of different endodontic sealers were analysed. A primary outcome measure was the resolution of periapical lesions following the endodontic treatment. In vivo studies comparing radiographic treatment outcomes and articles with a minimum of 6-month follow-up were included. A total of 9 clinical trial studies that met all the inclusion criteria were included in the analysis. The overall risk of bias was high in four studies out of nine studies. Periapical lesions showed significant healing after endodontic treatment regardless of sealer type, although bioceramic and bioactive sealers had shown better results.

Application of Fractal Analysis in Detecting Trabecular Bone Changes in Periapical Radiograph of Patients with Periodontitis.

INTRODUCTION: Evaluation of detailed features of the supporting bone is an important step in diagnosis and treatment planning for teeth with clinical attachment loss. Fractal analysis can be used as a method for evaluating the complexity of trabecular bone structures. The aim of this study was to evaluate the trabecular bone changes in periapical radiographs of patients with different stages of periodontitis using fractal analysis. METHODS: This comparative cross-sectional study was performed on patients with and without clinical attachment loss in mandibular first molars. Teeth with clinical attachment loss were divided into mild, moderate, and severe periodontitis groups. Digital periapical radiographs were obtained from the mandibular first molars using the same exposure parameters. DICOM file of the radiographs was exported to ImageJ software for fractal analysis. Three regions of interest (ROIs) were considered in each radiograph: two proximal ROIs mesial and distal to the mandibular first molar and one apical ROI. Fractal dimension (FD) values were calculated using the fractal box counting approach. Statistical analysis was performed using the chi-square test, Mann-Whitney test, intraclass correlation coefficient, and ANOVA (α = 0.05). RESULTS: FD values were significantly different between moderate and severe periodontitis and healthy periodontal bone (P < 0.05), except for the distal ROI for moderate periodontitis cases (P=0.280). However, FD values of the supporting bone in periodontally healthy teeth and teeth with mild periodontitis did not show a statistically significant difference (P > 0.05). CONCLUSION: Fractal analysis is a useful tool for evaluation of bone alterations in moderate and severe periodontitis, but was not able to detect the most initial radiographic bone signs of mild periodontitis.

Could the Calcium Silicate-Based Sealer Presentation Form Influence Dentinal Sealing? An In Vitro Confocal Laser Study on Tubular Penetration.

Dentinal tubule penetration influences root canal treatment sealing. The aim of this study was to compare dentinal penetration of two clinical presentations of silicate-based sealers using confocal laser. Sixty single-rooted human teeth from 50-70 year-old patients extracted for orthodontic/periodontal reasons were used. Canals were prepared using Mtwo system up to 35/0.04, with 5.25% NaOCl irrigation and final irrigation using 17% EDTA. Teeth were randomly assigned into study groups (ni = 20): EndoSequence BC sealer (ES, group 1), BioRoot RCS (BR, group 2); and a control group (nc = 20) with AH Plus (AHP). Root canals were obturated with 35/0.04 gutta-percha (single-cone technique). The samples were obtained from apical, middle, and coronal thirds. Dentinal tubule penetration depth and percentage of penetration around the canal perimeter were measured. The statistical analysis was performed using Mann Whitney U test and Wilcoxon t-test (95% confidence interval). ES exhibited a significantly higher penetration than AHP in apical and middle thirds (p < 0.05), and in middle and coronal thirds relative to BR (p < 0.05). The percentage of penetration around the canal perimeter was significantly higher for ES compared to BR in all thirds, but only in the apical third for AHP (p < 0.05). The pre-mixed silicate-based sealer exhibited better penetration than the powder/liquid one.

Cuspal Deflection and Temperature Rise of MOD Cavities Restored through the Bulk-Fill and Incremental Layering Techniques Using Flowable and Packable Bulk-Fill Composites.

Background: The aim of this study was to investigate cuspal deflection caused by material shrinkage and temperature rise occurring in the pulp chamber during photopolymerization. The aim of this study was also to investigate the effect of flowable and packable bulk-fill composites on cuspal deflection occurring in mesio-occlusal-distal (MOD) cavities restored through the bulk-fill or through the incremental layering technique. Additionally, mechanical and thermal properties of bulk-fill composites were considered. Methods: Two bulk-fill composites (high-viscosity and low-viscosity), largely differing in material composition, were used. These composites were characterized through linear shrinkage and compressive test. Cuspal deformation during restoration of mesio-occlusal-distal cavities of human premolars was evaluated using both the bulk-fill and the incremental layering techniques. Temperature rise was measured through thermocouples placed 1 mm below the cavity floor. Results: Shrinkage of the flowable composite was significantly higher (p < 0.05) than that of packable composite, while mechanical properties were significantly lower (p < 0.05). For cusp distance variation, no significant difference was observed in cavities restored through both restorative techniques, while temperature rise values spanned from 8.2 °C to 11.9 °C. Conclusions: No significant difference in cusp deflection between the two composites was observed according to both the restorative techniques. This result can be ascribed to the Young's modulus suggesting that the packable composite is stiffer, while the flowable composite is more compliant, thus balancing the cusp distance variation. The light curing modality of 1000 mW/cm2 for 20 s can be considered thermally safe for the pulp chamber.

Peri-implant Soft Tissue Management: Cairo Opinion Consensus Conference.

Peri-implant soft tissues play a role of paramount importance, not only on the esthetic appearance, but also on the maintenance and long-term stability of implants. The present report presents the conclusions from the Consensus Conference of the South European North African Middle Eastern Implantology & Modern Dentistry Association (SENAME) (4-6 November 2016, Cairo, Egypt). The conference focused on the topic of the soft tissue around dental implants, and in particular, on the influence of implant configurations on the marginal soft tissues, soft tissue alterations after immediate, early or delayed implant placement and immediate loading, the long-term outcomes of soft tissue stability around dental implants, and soft tissue augmentation around dental implants. Thirty world experts in this field were invited to take part in this two-day event; however, only 29 experts were in the final consensus voting process.

Management of Endodontic and Periodontal Lesions: the Role of Regenerative Dentistry and Biomaterials.

Regenerative dentistry represents a novel interdisciplinary approach involving biomaterials, several molecules and mesenchymal stem cells (MSCs), preferably derived from oral tissues. The pivotal role of MSCs depends on the fact that they can differentiate into different cell lineages and have the strategic role to release bioactive substances that stimulate the renewal and regeneration of damaged tissues. The role of regenerative dentistry is promising in all the branches of dentistry: the most intriguing application is related to the management of endodontic and periodontal defects, overcoming the surgical approach and the implantology as a consequence of a poorly efficient therapeutic plan.

Multifunctional Bioactive Resin for Dental Restorative Materials.

Resin-based composites are widely used as dental restorative materials due to their excellent properties. They must have high modulus, high hardness, and be chemically inert while minimizing moisture uptake. To fulfill these higher standard prerequisites and properties, continuous improvements in each of their components are required. This study develops novel composites with multiple biofunctions. Light-cured Bis-GMA/TEGDMA dental resin (RK)/layered double hydroxide intercalated with fluoride ions (LDH-F)/calcium bentonite (Bt) hybrid composites were prepared. The loading ratio of LDH-F to Bt was varied, ranging from 2.5/2.5 to 10/10 parts per hundred RK and structural, mechanical, and biological properties were studied. The incorporation of even small mass fractions (e.g., 2.5 wt % of LDH-F and 2.5 wt % of Bt) in RK dental resin significantly improved the mechanical properties of the pristine resin. The synthetized materials showed antibacterial and antibiofilm effects against three bacterial strains isolated from healthy volunteers' saliva (Streptococcus spp., Bacteroides fragilis, and Staphylococcus epidermidis) without affecting its ability to induce dental pulp stem cells differentiation into odontoblast-like cells. The capability to balance between the antibiofilm activity and dental pulp stem cells differentiation in addition with improved mechanical properties make these materials a promising strategy in preventive and restorative dentistry.

Dimensional changes following alveolar ridge preservation in the posterior area using bovine-derived xenografts and collagen membrane compared to spontaneous healing: a 6-month randomized controlled clinical trial.

OBJECTIVES: To assess dimensional changes following alveolar ridge preservation using bovine-derived xenograft with 10% collagen and collagen membrane compared to ridge preservation by means of bovine-derived xenograft particles and collagen membrane or spontaneous healing in posterior sites. MATERIALS AND METHODS: Forty subjects with 40 posterior teeth or roots candidate to extraction and presenting integrity of alveolar bone walls were randomly allocated into three groups. Patients of test group were treated by ridge preservation technique using bovine-derived xenograft with 10% collagen and collagen membrane; patients of control group 1 were treated by means of bovine-derived xenograft particles and collagen membrane while in patients of control group 2, no grafting was performed. Changes in vertical and horizontal bone dimensions were compared at baseline and after 6-month observation time. RESULTS: Statistically significant differences between baseline and 6 month were observed in all groups in terms of vertical and horizontal bone resorption (p < 0.001), except for vertical resorption in control group 2. After 6-month intergroup comparisons showed not statistically significant changes between test and control groups in terms of alveolar bone changes (p > 0.05). CONCLUSIONS: Within the limits of this study, the sites grafted using bovine-derived xenograft with 10% collagen in combination with a collagen membrane showed no statistical differences in terms of vertical and horizontal bone resorption compared to control groups. CLINICAL RELEVANCE: Ridge preservation in posterior area failed to show clinically relevant benefits in sites presenting integrity of alveolar bone walls and adequate buccal bone wall thickness.

Ridge preservation techniques to avoid invasive bone reconstruction: A systematic review and meta-analysis: Naples Consensus Report Working Group C.

PURPOSE: To analyse and compare the dimensional changes of unassisted extraction sockets with alveolar ridge preservation (ARP) techniques and investigate any factors that impact the resorption of the alveolar bone. MATERIALS AND METHODS: A systematic search was conducted to identify randomised clinical trials (RCTs). All data were extracted, and a meta-analysis was performed for the changes in all buccolingual ridge width, midbuccal and midlingual ridge height, and mesial and distal ridge height, and horizontal width at reference points apical to the crestal area. RESULTS: Based on 14 RCTs, the effectiveness of ARP in reducing the dimensions of the postextraction alveolar socket was confirmed. The clinical magnitude of this effect was 1.95 mm in the buccolingual ridge width, 1.62 mm in the midbuccal ridge height, and 1.26 mm on the midlingual ridge height. Additionally, 0.45 mm and 0.34 mm for mesial and distal ridge height, and 1.21 mm, and 0.76 mm for ridge width changes at points 3 and 5 mm apical to the crest were noted. Meta-regression analyses revealed that the reflection of flaps and primary wound coverage during ARP may have detrimental effects on bone remodelling, while no statistical significance was observed for any of the bone graft substitutes or the percentage of molar sockets. CONCLUSIONS: Regardless of the protocol, ARP can only minimise ridge resorption. ARP is most effective on horizontal ridge width, providing the most benefit coronally (approximating the crest), followed by the midbuccal ridge height.

In vitro Evaluation of the Marginal Fit and Internal Adaptation of Zirconia and Lithium Disilicate Single Crowns: Micro-CT Comparison Between Different Manufacturing Procedures.

BACKGROUND: Prosthetic precision can be affected by several variables, such as restorative materials, manufacturing procedures, framework design, cementation techniques and aging. Marginal adaptation is critical for long-term longevity and clinical success of dental restorations. Marginal misfit may lead to cement exposure to oral fluids, resulting in microleakage and cement dissolution. As a consequence, marginal discrepancies enhance percolation of bacteria, food and oral debris, potentially causing secondary caries, endodontic inflammation and periodontal disease. OBJECTIVE: The aim of the present in vitro study was to evaluate the marginal and internal adaptation of zirconia and lithium disilicate single crowns, produced with different manufacturing procedures. METHODS: Forty-five intact human maxillary premolars were prepared for single crowns by means of standardized preparations. All-ceramic crowns were fabricated with either CAD-CAM or heat-pressing procedures (CAD-CAM zirconia, CAD-CAM lithium disilicate, heat-pressed lithium disilicate) and cemented onto the teeth with a universal resin cement. Non-destructive micro-CT scanning was used to achieve the marginal and internal gaps in the coronal and sagittal planes; then, precision of fit measurements were calculated in a dedicated software and the results were statistically analyzed. RESULTS: The heat-pressed lithium disilicate crowns were significantly less accurate at the prosthetic margins (p<0.05) while they performed better at the occlusal surface (p<0.05). No significant differences were noticed between CAD-CAM zirconia and lithium disilicate crowns (p>0.05); nevertheless CAD-CAM zirconia copings presented the best marginal fit among the experimental groups. As to the thickness of the cement layer, reduced amounts of luting agent were noticed at the finishing line, whereas a thicker layer was reported at the occlusal level. CONCLUSION: Within the limitations of the present in vitro investigation, the following conclusions can be drawn: the recorded marginal gaps were within the clinical acceptability irrespective of both the restorative material and the manufacturing procedures; the CAD-CAM processing techniques for both zirconia and lithium disilicate produced more consistent marginal gaps than the heat-pressing procedures; the tested universal resin cement can be safely used with both restorative materials.

Mechanical and Thermal Properties of Dental Composites Cured with CAD/CAM Assisted Solid-State Laser.

Over the last three decades, it has been frequently reported that the properties of dental restorative composites cured with argon laser are similar or superior to those achieved with conventional halogen and light emitting diode (LED) curing units. Whereas laser curing is not dependent on the distance between the curing unit and the material, such distance represents a drawback for conventional curing units. However, a widespread clinical application of this kind of laser remains difficult due to cost, heavy weight, and bulky size. Recently, with regard to the radiation in the blue region of the spectrum, powerful solid-state lasers have been commercialized. In the current research, CAD (computer-aided design)/CAM (computer-aided manufacturing) assisted solid-state lasers were employed for curing of different dental restorative composites consisting of micro- and nanoparticle-reinforced materials based on acrylic resins. Commercial LED curing units were used as a control. Temperature rise during the photopolymerisation process and bending properties were measured. By providing similar light energy dose, no significant difference in temperature rise was observed when the two light sources provided similar intensity. In addition, after 7 days since curing, bending properties of composites cured with laser and LED were similar. The results suggested that this kind of laser would be suitable for curing dental composites, and the curing process does not suffer from the tip-to-tooth distance.

Neural stem cells from a mouse model of Rett syndrome are prone to senescence, show reduced capacity to cope with genotoxic stress, and are impaired in the differentiation process.

Several aspects of stem cell life are governed by epigenetic variations, such as DNA methylation, histone modifications, and chromatin remodeling. Epigenetic events are also connected with the impairment of stem cell functions. For example, during senescence, there are significant changes in chromatin organization that alter transcription. The MECP2 protein can bind methylated cytosines and contribute to regulating gene expression at one of the highest hierarchical levels. Researchers are particularly interested in this protein, as up to 90% of Rett syndrome patients have an MECP2 gene mutation. Nevertheless, the role of MECP2 in this disease remains poorly understood. We used a mouse model of Rett syndrome to evaluate whether residual MECP2 activity in neural stem cells (NSCs) induced the senescence phenomena that could affect stem cell function. Our study clearly demonstrated that the reduced expression of MECP2 is connected with an increase in senescence, an impairment in proliferation capacity, and an accumulation of unrepaired DNA foci. Mecp2 +/- NSCs did not cope with genotoxic stress in the same way as the control cells did. Indeed, after treatment with different DNA-damaging agents, the NSCs from mice with mutated Mecp2 accumulated more DNA damage foci (γ-H2AX+) and were more prone to cell death than the controls. Senescence in Mecp2 +/- NSCs decreased the number of stem cells and progenitors and gave rise to a high percentage of cells that expressed neither stem/progenitor nor differentiation markers. These cells could be senescent and dysfunctional.

Clinical Outcomes of Socket Preservation Using Bovine-Derived Xenograft Collagen and Collagen Membrane Post-Tooth Extraction: A 6-Month Randomized Controlled Clinical Trial.

The aim of this study was to evaluate the clinical remodeling of the alveolar socket following the application of bovine-derived xenograft collagen and collagen membrane compared to natural spontaneous healing during the first 6 months following tooth extraction. A total of 20 patients with 20 fresh alveolar sockets were randomly allocated into a test or control group. After a 6-month follow-up period, surgical reentry was performed and implants were placed. Significant statistical differences were recorded in terms of vertical and horizontal bone changes between the test and control groups. Within the limitations of this study, socket preservation procedures may provide more favorable conditions for subsequent implant placement.

Four-year post-loading results of full-arch rehabilitation with immediate placement and immediate loading implants: A retrospective controlled study.

OBJECTIVES: The aim of this study was to evaluate implant survival rate and to measure peri-implant bone changes in full-arch rehabilitations with immediate placement and immediate loading implants with platform switching and Morse taper connection, in addition to platelet-rich fibrin (PRF) and buccal bone augmentation, after 4 years of follow-up. METHOD AND MATERIALS: In this retrospective controlled study, patients who had been fully rehabilitated with immediate placement and immediate loading implants were evaluated 4 years post-loading. Implants with platform switching and Morse taper connections were used (In-Kone Universal System, Global D) and PRF and buccal bone augmentation were applied. The radiographic bone loss was calculated by subtracting the bone level at baseline (BLT0) from that at the 4-year follow-up (BLT4) in immediate and delayed implants. Measurements were made at the distal, mesial, vestibular, and oral sites of the implants and the deepest value was recorded. Implants placed in extraction sites and implants placed in healed sites were considered. A comparison between the groups was performed using the Mann-Whitney test. The implant survival rate was calculated using the Kaplan-Meier analysis. RESULTS: In total, 42 patients (28 females and 14 males; average age 55.8 years old, age range 45 to 77) were recruited to this study. A total of 334 implants were put in place (226 in the maxilla, 108 in the mandible). The implant survival rate was 97.8% for the maxilla and 98.1% for the mandible, 98.3% for immediate implants and 96.9% for delayed implants. No statistically significant differences (P > .05) in the mean radiographic bone loss (mBL) were observed when comparing the immediate and delayed implants and the anterior and posterior implants. Statistically significant differences were found in the mBL between the mandibular and maxilla implants in the vestibular (P = .01) and mesial (P = .001) sites. CONCLUSION: Within their limits, the present results suggest that rehabilitation with platform switching and taper connection implants, in addition to buccal bone augmentation and the use of PRF, can lead to predictable results.

Polyacrylic resins regulate transcriptional control of interleukin-6, gp80, and gp130 genes in human gingival fibroblasts.

Studies have failed to identify the molecular mechanisms that regulate the genotoxic and cytotoxic effects of methacrylate resins, which are important in the biocompatibility of dental materials. Interleukin (IL)-6 has a crucial role in the control of acute-phase protein response during inflammation. In humans, the synthesis and release of two major acute-phase proteins, C-reactive protein and serum amyloid A, are regulated by IL-6. This study focused on IL-6 and activation of its receptors gp80 and gp130 in human gingival fibroblasts in order to assess the effects of the commercial acid resins Jet Kit, Unifast, and Duralay on control of inflammation.

Penetration of hypochlorites with lowered surface tension into dentine tubules.

BACKGROUND: The purpose of the present study was to assess the effect of concentration and temperature of sodium hypochlorite (NaOCl) with added surfactants and time of exposure on its penetration into human dentine. METHODS: Seventy-five extracted permanent maxillary anterior teeth with single canals were shaped by using ProTaper SX hand-operated instruments. Then teeth were sectioned perpendicular to their long axis. The crowns and apical thirds of all the teeth were removed. The remaining roots were processed into 4-mm-long blocks and stained overnight in crystal violet. One hundred fifty stained blocks were further split into halves and treated by six NaOCl-based solutions from different brands: three solutions added with surfactants (Hypoclean, H6, Chlor-Xtra) and their regular counterparts (5.25%, 6%, <%6NaOCl). The dentine blocks were exposed to the solutions for 2, 5, and 20 minutes at 20° C, 37° C, and 45° C, respectively. The depth of penetration of NaOCl was determined by bleaching of the stain and measured by light microscopy at magnifications of 20x and 40x. Statistical analysis was made by using two way ANOVA and by comparing groups two by two with t-test. RESULTS: The shortest penetration (130.80±1.92µm) was measured after incubation with 5.25%NaOCl for 2 minutes at 20° C; the highest penetration (375.40±3.05µm) was obtained with Chlor-Xtra for 20 minutes at 45° C. Temperature and exposure time had a significant direct relationship with penetration of sodium hypochlorites with lowered surface tension into dentinal tubules. CONCLUSIONS: The exposure time and temperature of sodium hypochlorite as well as the addition of surfactants may influence the penetration depth of irrigants into dentinal tubules.

The Relevance of the Use of Radiographic Planning in Order to Avoid Complications in Mandibular Implantology: A Retrospective Study.

The aim of this retrospective radiological study was to evaluate the variability of the mandibular anatomy in the presence and absence of teeth and to consider how it could influence implant planning. 187 mandibular CT DentaScans were selected from our department archive according to the inclusion criteria. The axial height, vertical height, angulation of the bone crest, and the bone available for ideal implant placement were measured. The analysis of the data shows that the mandible contour presents a constant degree of angulation. The variation of angulation in the absence of teeth was statistically significant only in the region between the canine and the first premolar and in that between the second premolar and the first molar. The difference between the crest height and the available distance to place the implant was greater in the region of the second molar while in the other regions the implant planning was made complex by postextraction resorption. Alveolar bone resorption after tooth loss can be considered as a risk factor for lingual cortical perforation during the insertion of an implant. To avoid potential intra/postoperative complications, 3D radiographic examination is recommended in order to study the mandibular anatomy and identify the risk areas.