American journal of dentistry最新文献

Purpose: To describe a surgical technique for oroantral communication closure and bone regeneration that can meet the needs of an effective, less invasive, and simpler surgery using approaches and biomaterials used in guided bone regeneration (GBR) techniques. The main objective was to close the communication, and the secondary was to achieve bone regeneration.

Methods: This retrospective and monocentric case series was conducted using data obtained from the medical records of 28 patients with oroantral communications with bone deficits greater than 3 mm and treated with heterologous cortico-cancellous graft covered with resorbable collagen membranes and heterologous cortical lamina. The primary outcome was closure of the communication, and the secondary outcome was bone augmentation, both tested radiographically and clinically.

Results: 28 subjects were treated consecutively for the closure of oroantral communications. The subjects included 16 men and 12 women. The mean age was 57.5 years. Closure was successful in all 28 cases, and radiographic control after 6 months showed bone regeneration in all the cases. This technique was effective in isolating the maxillary sinus from the oral cavity, showing results in terms of seal and healing, and bone regeneration.

Clinical significance: Oroantral communications are frequent in dentistry, requiring special expertise and interventions affecting patient morbidity. The use of a heterologous cortical lamina can allow effective closure of the communication, preventing migration of pathological epithelia while increasing the bone ridge.

Purpose: To provide an overview of an innovative surgical approach to guided bone regeneration, the Pack Into Bone (PIB) technique.

Methods: Twenty subjects, eight men and 12 women, aged 34 to 68 (mean 51.5) were selected. They were treated with the PiB technique, and upon re-entry surgery, performed 8 months postoperatively, implants were placed, and bone samples were collected by using trephine burs for histological and histomorphometric analysis purposes.

Results: Mean ridge width varied between 4.71 (W0) mm and 7.37 mm (W1), measured 8 months postoperatively, with a mean W augmentation of 2.69 mm ± 0.19. Mean height ranged between 8.0 mm (H0) and 11.15 mm (H1), measured 8 months after surgery with a mean augmentation of 3.53 mm ± 0.14 (P< 0.05).

Clinical significance: Stability and versatility are the pillars of the PIB technique compared to common GBRs. The PIB technique is effective and reduces the difficulty in stabilizing the graft, is more feasible for operators, and decreases morbidity for the subjects.

Purpose: This retrospective observational study aims to evaluate the outcome of a new alveolar ridge preservation (ARP) technique, "Lamina Socket Sealing" (LSS) technique, using a porcine barrier.

Methods: 36 subjects with maxillary premolars to be extracted and extensive alveolar wall defects were enrolled and treated. Porcine-derived barriers and mesenchymal membrane were used to seal the extraction socket with alveolar particulate graft. The outcome variables were: radiographical bone changes and clinical outcomes.

Results: 36 subjects, 21 females and 15 males were treated. The change in mm (mean + SE) of horizontal ridge width from baseline to 4 months after surgery at the coronal level of the alveolus was +1.25 ± 0.20 mm (P< 0.05), mean level was +0.34 ± 0.1 mm (P< 0.05) and at the apical level was +0.08 ± 0.17 mm (P> 0.05) which was not statistically significant. The buccal and palatal height changes in mm (mean + SE) from baseline to 4 months after surgery were respectively 1.21 ± 0.17 mm for the buccal wall (P< 0.05) and 1.06 ± 0.24 mm for the palatal wall (P< 0.05). The bone volume of all sites allowed for the placement of the planned implants.

Clinical significance: The alveolar ridge preservation technique (Lamina Socket Sealing) using resorbable heterologous cortical lamina with flapless approach allowed not only the preservation of the damaged post-extraction socket, but also minimal ridge augmentation, according to the principles of guided bone regeneration.

Purpose: This retrospective observational study evaluated the histomorphometric and soft tissue outcome of a new alveolar ridge preservation (ARP) technique, "Lamina Socket Sealing" (LSS) technique, using a porcine barrier.

Methods: Patients with maxillary premolars to be extracted and extensive alveolar wall defects were enrolled and treated. Porcine-derived barriers and mesenchymal membrane were used to seal the extraction socket with alveolar particulate graft. An optical scan of the dental arches was performed with an intraoral scanner (Trios 3, 3Shape) at baseline and at a 4-month follow-up. At the time of implant placement, a bone sample was taken at the implant site with a trephine drill (Hager & Meisinger) and subjected to histomorphometric analysis.

Results: 36 subjects (21 females and 15 males) were treated. At 4 months, histomorphometric analysis of the bone samples revealed that the percentage of vital bone was 42.87%, 8.75% of residual granules, 30.76% of soft tissue. Linear comparison of the width of the keratinized gingiva showed an increase (mean + SE) of 3.16 ± 0.35 mm. The net volumetric change of soft tissue was (mean + SE) +28.41 ± 19.52 mm³.

Clinical significance: This alveolar ridge preservation technique (Lamina Socket Sealing) using a resorbable heterologous cortical lamina with a flapless approach has proven effective in maintaining adequate soft tissue and grafting of particulate bone and lamina, with a high percentage of viable bone.

Purpose: This retrospective study measured the increase in bone tissue using the transcrestal maxillary sinus floor elevation with injectable xenogeneic bone substitute in gel form with simultaneous implant placement. This procedure allows elevation of the sinus floor atraumatically, reducing the risk of perforation of the Schneiderian membrane.

Methods: 52 subjects needing unilateral sinus floor elevation, with a residual crestal height from 2 mm to 5 mm, and a request for at least one implant-prosthetic rehabilitation in the posterior maxillary area were enrolled. Transcrestal maxillary sinus floor elevation was performed with injectable xenogeneic bone substitute in gel form. The sinus elevation was measured after the surgery and 6 months later with a CBCT. Average values were calculated for each measure.

Results: 46 implants were simultaneously placed; six implants were placed after 4 months because of the lack of primary stability. All the placed implants, with a follow-up varying from 3 to 5 years after loading, osseointegrated successfully resulting in a survival rate of 100%. Average pre-operative bone height was 4.2 mm while after the surgery the average value reached was 10.1 mm with an average value of new bone gain of 6.43 mm. Histological analysis revealed the presence of 33.2% of vital bone.

Clinical significance: Transcrestal sinus floor elevation with injectable xenogenic bone substitute in gel form is a minimally invasive technique that can reduce the incidence of Schneider membrane perforations, making a widely used method, such as sinus floor elevation, safer and less operator dependent.

Purpose: This retrospective study evaluated the effectiveness of a technique for the management of maxillary sinus floor augmentation.

Methods: Nineteen subjects [7 males, 12 females, mean age 53.3±10.5 (standard deviation) years], who experienced membrane perforation during lateral sinus lift procedure, were included. Perforations were managed either using the "Sinus Pack" technique (test, 11 subjects) or collagen membranes and resorbable sutures (control, eight subjects). Clinical and radiological outcomes were assessed.

Results: The mean follow-up was 18.3± 11.7 months (range 5-40 months). A significantly lower mean vertical gain was observed in the control group (7.8± 0.9 mm), compared to the sinus pack approach (8.8± 0.9 mm) (P= 0.04), but both were effective for implant-prosthetic rehabilitation.

Clinical significance: The "Sinus Pack" technique was effective in managing perforations during sinus floor elevation surgery, allowing the completion of the surgical procedure even in cases of large perforations.

Purpose: To evaluate the antimicrobial activity of dentifrices based on Malva sylvestris and propolis and the effect on the acrylic resin.

Methods: The inhibitory effect against Candida albicans, Enterococcus faecalis and Streptococcus mutans was determined. The specimens of resin were divided into groups: Control (brushing with distilled water); brushing with Colgate; brushing with Protex; brushing with Malvatricin, brushing with Proporalcare Dental Gel and brushing with Green Propolis Dental Gel. Brushing was carried out in a brushing machine. Roughness and color were assessed. The data were analyzed by ANOVA, followed by the Bonferroni post test (α= 0.05).

Results: The products evaluated showed antimicrobial activity against all microorganisms (P< 0.05), except Proporalcare Dental Gel, which was not effective against E. faecalis. Greater roughness (P< 0.05) was observed in the samples treated with Colgate. The samples from control and Protex groups showed the lowest color variation and the highest luminosity, with a difference in relation to the others (P< 0.05), which showed higher values, although clinically acceptable.

Clinical significance: The dentifrices based on natural products can be indicated for cleaning prostheses, since they showed antimicrobial activity and did not cause perceptible color changes of the resin tested. The dentifrices did not produce adverse effects on the surface of the resin or did so less than the conventional dentifrice.

Purpose: To investigate the effect of different abutments and crowns on the color of implant-supported restorations.

Methods: Zirconia and lithium disilicate (e.max) disks with A2 shade were fabricated to represent two crowns. The implant abutments were untreated titanium, opaqued titanium, anodized titanium, A2 shade zirconia and white zirconia. 4.0 mm-thickness zirconia and e.max specimens were used as references respectively. The crowns were placed on tested abutments with a drop of clear glycerin between them and the color was measured using a digital spectrophotometer. CIELab values were recorded to evaluate color differences (ΔE) between tested specimens and the references.

Results: Titanium abutments presented higher color differences than zirconia. The ΔE values with untreated titanium were higher than those with opaqued titanium. No differences were found between untreated titanium and anodized titanium for zirconia crowns. The ΔE values of zirconia crowns showed no significant differences between shade A2 zirconia and white zirconia abutments; e.max crowns showed a significant difference. The zirconia crown ΔE values were lower than those of e.max for all titanium and A2 zirconia abutments. Lithium disilicate crowns and zirconia abutments may be more suitable for implant-supported restorations. Opaqued titanium abutment may improve color in esthetic regions when a ceramic abutment cannot be used.

Clinical significance: Lithium disilicate crowns and zirconia abutments may be an effective method to achieve excellent color matching in esthetic regions with implant-supported restorations.

Purpose: To evaluate different polishing methods' effects on the color stability of recent resin composites.

Methods: 160 samples for color stability evaluation and 40 samples for the degree of conversion evaluation were prepared with four different resin composites [Harmonize (H), Filtek Universal (F), Omnichroma (O), Essentia Universal (E)] and light cured. For color stability evaluation, samples prepared from each resin composite were divided into four groups: three polishing procedures and a control group. The ΔE₀₀ was calculated between initial, and after immersion in coffee solution for 12 days. The degree of conversion was evaluated with Fourier Transform Infrared Spectroscopy. The statistical analysis of ΔE₀₀ values was made with the two-way ANOVA, Tukey HSD, and Tamhane's T2 tests. One-way ANOVA and Tukey HSD tests were used to compare the degree of conversion values (P< 0.05).

Results: In all composite groups, mylar (control) groups had the highest ΔE₀₀, and no differences between other polishing procedures. According to the polishing procedures, Omnichroma showed the highest ΔE₀₀ values (on mylar groups O vs F, P< 0.001; O vs H, P< 0.001; O vs E, P< 0.001). There was a significant difference between the composite groups in terms of the degree of monomer conversion (P< 0.05). Omnichroma showed, significantly, the highest discoloration.

Clinical significance: Different polishing procedures showed effective performance on current composite surfaces. Omnichroma resin composite showed higher color change than composites with similar properties.

Purpose: To investigate the effect of different chemical compositions of primers on the bond strength between nano-ceramic, polymer-infiltrated ceramic, and zirconia ceramic materials and dual-cure cement.

Methods: Fifty 2 mm-thick specimens were prepared from Vita Enamic, Cerasmart, and Katana Zirconia UTML. The specimens were embedded in acrylic blocks. To standardize the surfaces, 600 grit silicon carbide abrasives were applied underwater for 60 seconds. Then, each section underwent grit-blasting using Al₂O₃ with a particle size of 50 µm at 10 mm and a pressure of 2 bar for 10 seconds. Each prepared sample from the experimental groups received the appropriate primer (Z-PRIME Plus, G-Multi Primer, Alloy Primer, Clearfil Primer Plus) according to the manufacturers' instructions. Subsequently, the prepared CAD-CAM specimens underwent cementation using Duo-Link Universal Adhesive Resin Cement with a cylinder mold of 2.6 mm diameter and 3 mm height. The cement was light-cured for 20 seconds from both sides. The specimens obtained were stored in distilled water at 37°C for 24 hours. The shear bond strength test of the specimens was performed using a Bisco Shear Bond Tester device. The data were statistically analyzed using ANOVA and the Kruskal-Wallis test (P< 0.05).

Results: The highest bond strength was observed in Z-Prime Plus applied specimens, regardless of material differences (Cerasmart 11.60±4.61; Vita Enamic 12.93±3.86; Katana Zirconia 13.85±4.00). The lowest bond strength, showing differences according to materials (P< 0.05), was found for Clearfil Ceramic Primer Plus-Cerasmart (7.88±3.90), Alloy Primer-Vita Enamic (7.90±2.14), and G Multi Primer-Katana Zirconia UTML (4.98±3.67).

Clinical significance: Failure of the restoration usually occurs at the weakest point in this three-element structure, thus correct primer selection according to material type is important. Additionally, for all CAD-CAM materials used in the study, Z-Prime Plus showed significantly greater adhesion strength than other systems so it may be more appropriate for use in clinics.