American journal of dentistry最新文献

Purpose: To highlight the different risk factors, whether surgical or anatomical, related to Schneiderian membrane perforation, while evaluating the predictability of currently available methods to manage such perforations.

Methods: Charts of subjects experiencing perforation during maxillary sinus augmentation were retrospectively reviewed. Data related to possible anatomical and surgical risk factors were extracted. The correlation between membrane perforation size and anatomical risk factors (e.g., sinus septa, residual bone height and membrane thickness), surgical risk factors (satisfactory clinical management score - SCMs) and implant outcomes was statistically evaluated.

Results: Nine out of 10 subjects with perforation size ≥5 mm presented a less than 1.5 mm (P= 0.011) sinus membrane thickness. About 80% of subjects with easy or fair SCMs presented a residual bone height lower than 4 mm (P= 0.02) The SCMs were significantly worse in subjects with a perforation size ≥ 5 mm (2.8 ± 1.5) compared to those with a perforation size < 5 mm (1.4 ± 0.7) (P= 0.03).

Clinical significance: Techniques for the management of Schneider's membrane perforation should take into consideration anatomical and surgical risk factors, to render surgical therapies more predictable, reducing patient morbidity.

Purpose: To evaluate the efficacy of lateral ridge augmentation (LRA) of porcine cortical barriers when placed in a surgical bone gap, buccal to the defect, using the Bone into Bone (BiB) technique compared to a guided bone regeneration (GBR) technique.

Methods: The study was a retrospective case-control evaluation. A group of 23 subjects (test) underwent horizontal augmentation procedures using the BiB technique. A group of 18 subjects (control) was treated with the guided bone regeneration (GBR) technique, using a resorbable membrane and a mixture of heterologous bovine particles and autologous bone fragments. Radiological and histological analysis of the outcomes were performed.

Results: Mean ridge width varied from a preoperative value of 3.4 mm to a postoperative value, measured 8 months postoperatively, of 7.1 mm in the Control Group. The mean ridge width varied from a preoperative value of 4.8 mm to a postoperative value, measured 8 months after the procedure, of 7.5 mm in the Test Group. Histological images, after 8 months, showed native, mineralized bone with a lamellar pattern of varying thickness (30.3% ± 5.3).

Clinical significance: This technique (Bone-into-Bone) using resorbable heterologous biomaterials and without the use of retention devices for horizontal bone augmentation may be a viable alternative that is easily reproducible and has reduced morbidity for the patient.

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.