Implant-Supported Prosthetic Rehabilitation of a Patient With Squamous Cell Carcinoma: A Case Report.

Patients who have undergone maxillary resection procedures are rehabilitated with dental obturators or microvascular reconstruction. This case report describes implant-supported prosthetic rehabilitation of a patient who underwent maxillary resection because of squamous cell carcinoma. After maxillectomy surgery, the patient was rehabilitated using a surgical obturator for 1 week, followed by an interim obturator until the surgical field was completely healed. For definitive prosthesis, different treatment options were presented from which the patient selected an implant-supported maxillofacial prosthesis and a removable mandibular partial prosthesis. Under general anesthesia, 2 zygomatic implants and 4 conventional implants to the posterior maxilla were inserted. After a healing period, the bar-retained maxillofacial prosthesis and removable mandibular partial denture were fabricated. The patient was satisfied regarding function, esthetics, speech, and swallowing. No problems, except slight discoloration of the prosthesis, were noted at the 6-month follow-up. Implant-supported maxillofacial prostheses are a valuable treatment option to improve quality of life after maxillary resection.

Comparison of temperature change among different adhesive resin cement during polymerization process.

PURPOSE: The aim of this study was to assess the intra-pulpal temperature changes in adhesive resin cements during polymerization. MATERIALS AND METHODS: Dentin surface was prepared with extracted human mandibular third molars. Adhesive resin cements (Panavia F 2.0, Panavia SA, and RelyX U200) were applied to the dentin surface and polymerized under IPS e.max Press restoration. K-type thermocouple wire was positioned in the pulpal chamber to measure temperature change (n = 7). The temperature data were recorded (0.0001 sensible) and stored on a computer every 0.1 second for sixteen minutes. Differences between the baseline temperature and temperatures of various time points (2, 4, 6, 8, 10, 12, 14, and 16 minute) were determined and mean temperature changes were calculated. At various time intervals, the differences in temperature values among the adhesive resin cements were analyzed by two-way ANOVA and post-hoc Tukey honestly test (α = 0.05). RESULTS: Significant differences were found among the time points and resin cements (P < 0.05). Temperature values of the Pan SA group were significantly higher than Pan F and RelyX (P < 0.05). CONCLUSION: Result of the study on self-adhesive and self-etch adhesive resin cements exhibited a safety intra-pulpal temperature change.

Effect of surface treatments on the bond strength of soft denture lining materials to an acrylic resin denture base.

STATEMENT OF PROBLEM: Adhesive failure between acrylic resin and resilient liner material is commonly encountered in clinical practice. PURPOSE: The purpose of this study was to evaluate the effect of different surface treatments on the bond strength of 2 different resilient lining materials to an acrylic resin denture base. MATERIAL AND METHODS: Ninety-six dumbbell-shaped specimens were fabricated from heat-polymerized acrylic resin, and 3 mm of the material was cut from the thin midsection. The specimens were divided into 6 groups according to their surface treatments: no surface treatment (control group), 36% phosphoric acid etching (acid group), erbium:yttrium-aluminum-garnet (Er:YAG) laser (laser group), airborne-particle abrasion with 50-µm Al2O3 particles (abrasion group), an acid+laser group, and an abrasion+laser group. The specimens in each group were divided into 2 subgroups according to the resilient lining material used: heat-polymerized silicone based resilient liner (Molloplast B) and autopolymerized silicone-based resilient liner (Ufi Gel P). After all of the specimens had been polymerized, they were stored in distilled water at 37°C for 1 week. A tensile bond strength test was then performed. Data were analyzed with a 2-way ANOVA, and the Sidak multiple comparison test was used to identify significant differences (α=.05). The effects of the surface treatments and resilient lining materials on the surface of the denture base resin were examined with scanning electron microscopy. RESULTS: The tensile bond strength was significantly different between Molloplast B and Ufi Gel P (P<.001). The specimens of the acid group had the highest tensile bond strength, whereas those of the abrasion group had the lowest tensile bond strength. The scanning electron microscopy observations showed that the application of surface treatments modified the surface of the denture base resin. CONCLUSIONS: Molloplast B exhibited significantly higher bond strength than Ufi Gel P. Altering the surface of the acrylic resin denture base with 36% phosphoric acid etching increased bond strength.

Investigation of the effect of different polishing techniques on the surface roughness of denture base and repair materials.

STATEMENT OF PROBLEM: The rough surface of denture base materials may cause plaque accumulation and staining. Thus, the effectiveness of polishing techniques should be known. PURPOSE: The purpose of this study was to compare the effects of chairside polishing kits and conventional laboratory techniques on the surface roughness of denture base and repair materials. MATERIAL AND METHODS: Ninety-six specimens, 50 ±1 mm in diameter and 0.5 ±0.05 thick, were fabricated from heat-polymerized acrylic resin (HP), polyamide resin (PR), and autopolymerizing resin (AP) and submitted to grinding with a tungsten carbide bur. The specimens were divided into 4 groups according to the polishing technique used: control group without polishing, conventional laboratory polishing, polished with Acrylic Polisher HP blue kit, and polished with AcryPoint polishing kit. Surface roughness (Ra) was measured after polishing with a profilometer. Data were analyzed with a 2-way analysis of variance, and the Tukey honestly significant difference (HSD) test was performed to identify significant differences (α=.05). RESULTS: The polishing techniques significantly affected the Ra of denture base materials (P<.001). The highest mean average Ra was measured for the control group. The lowest Ra values were determined in specimens exposed to conventional laboratory polishing techniques. No significant differences were found between Acrylic Polisher HP blue and AcryPoint polishing kits (P>.05). Statistically significant differences were found in the Ra between the PR and both the HP and AP (P<.001); PR exhibited the highest Ra values. CONCLUSIONS: Conventional laboratory polishing was the most effective polishing technique. A significantly smoother surface than that of the specimens in the control group was produced with chairside silicone polishing kits.

Effect of repair resin type and surface treatment on the repair strength of heat-polymerized denture base resin.

STATEMENT OF PROBLEM: Acrylic resin denture fracture is common in prosthodontic practice. When fractured denture bases are repaired, recurrent fractures frequently occur at the repair surface interface or adjacent areas. PURPOSE: The purpose of this study was to evaluate the effect of different surface treatments on the flexural strength of the acrylic resin denture base repaired with heat-polymerized acrylic resin, autopolymerizing resin, and light-polymerized acrylic resin. MATERIAL AND METHODS: Ninety-six specimens of heat-polymerized acrylic resin were prepared according to the American Dental Association Specification No. 12 (65.0 × 10.0 × 2.5 mm) and sectioned into halves to create a repair gap (3.0 × 10 × 2.5 mm). The sectioned specimens were divided into 3 groups according to their repair materials. The specimens from each group were divided into 4 subgroups according to their surface treatments: a control group without any surface treatment; an experimental group treated with methyl methacrylate monomer (MMA group); an experimental group treated with airborne-particle abrasion with aluminum oxide particles of 250-µm particle size (abrasion group); and an experimental group treated with erbium:yttrium-aluminum-garnet laser (laser group). After the surface treatments, the 3 materials were placed into the repair gaps and then polymerized. After all of the specimens had been ground and polished, they were stored in distilled water at 37°C for 1 week and subjected to a 3-point bend test. Data were analyzed with a 2-way analysis of variance, and the Tukey honestly significant difference test was performed to identify significant differences (α=.05). The effects of the surface treatments and repair resins on the surface of the denture base resin were examined with scanning electron microscopy. RESULTS: Significant differences were found among the groups in terms of repair resin type (P<.001). All surface-treated specimens had higher flexural strength than controls, except the surface treated with the methyl methacrylate in the heat-polymerized group. A significant difference between the control and abrasion groups (P=.013) was found. The scanning electron microscopy observations showed that the application of surface treatments modified the surface of the denture base resin. CONCLUSIONS: The repair procedure with heat-polymerized resin exhibited significantly higher flexural strength than that of the autopolymerized and light-polymerized resins. In addition, the airborne-particle abrasion with aluminum oxide particles of 250-µm particle size improved the flexural strength of the specimens tested.

MiR-4484 Acts as a Potential Saliva Biomarker for Early Detection of Peri-implantitis.

PURPOSE: Peri-implantitis, a potentially progressive disease that occurs in patients with dental implants, is more aggressive than periodontal lesions, which makes the prevention of peri-implantitis an important priority. Due to problems in the early detection of peri-implantitis, there is an urgent need for discovering novel biologic molecules with the ability of early diagnosis. The goal of this study was to profile the microRNA content of saliva samples collected from patients with titanium-aluminum-vanadium alloy dental implants who experienced peri-implantitis and to find potential diagnostic markers for detection of this disease. MATERIALS AND METHODS: The microRNA expression profiles of eight saliva samples (four collected from patients with peri-implantitis, four collected from patients who have successful implants) were investigated, and the deregulation of select microRNAs was further confirmed using quantitative polymerase chain reaction. RESULTS: The expressions of 179 microRNAs were found as deregulated in the saliva of peri-implantitis patients in comparison to controls. Then, downregulation of miR-4484 was confirmed in the saliva of peri-implantitis patients in a larger validation cohort. Also, 40% of non-peri-implantitis patients and 78% of peri-implantitis patients had significantly decreased miR-4484 expression in saliva samples collected after 4 to 6 months subsequent to implant placement compared with samples collected before implant placement. CONCLUSION: Considering these findings, microRNA content of saliva might be proposed as a plausible source for the early diagnosis of peri-implantitis, where miR-4484 might serve as an encouraging early diagnostic biomarker.

Effect of staining and bleaching on the microhardness, surface roughness and color of different composite resins.

BACKGROUND: There are studies that examined the effect of staining on the surface properties of composite resins, using different solutions and bleaching applications. However, the effect of both staining and bleaching on the same composite specimens is an issue that needs to be investigated. OBJECTIVES: The aim of this study was to investigate the surface microhardness, roughness and color changes (ΔE) of 2 different composite resins after staining and bleaching. MATERIAL AND METHODS: A microhybrid and a nanohybrid composite were used in the study. One hundred and fifty specimens were prepared from each composite. The specimens were divided into 5 groups and stained for 30 days with tea, coffee, cola, red wine, or distilled water (control). Subsequently, each group was divided into 3 subgroups. Each subgroup received a 14-day application of Opalescence™ Boost, Opalescence PF or VivaStyle® Paint On Plus bleaching materials. The color as well as surface microhardness and roughness of all specimens were determined at baseline, after staining and after bleaching. Data was analyzed using the repeated-measures analysis of variance (ANOVA) and the Bonferroni method. RESULTS: A statistically significant decrease was observed in the surface microhardness of the microhybrid composite specimens after bleaching (p < 0.05).The highest ΔE values were observed in the red wine groups for both composite resins. CONCLUSIONS: Staining and bleaching may affect surface properties and color, depending on the type, filler and matrix content of the composite resin.

Effect of Super-Bond C&B and self-adhesive dual-cured resin cement on the fracture resistance of roots with vertical root fracture.

Background. Vertical root fracture might occur during root canal preparation, obturation, post procedures or endodontic treatment. Methods. Fifty-four single-rooted human teeth were decoronated to obtain a standardized length. The root canals were enlarged up to #50 and obturated with gutta-percha and root canal sealer. Eighteen teeth were used as a control group, and vertical root fracture was induced in the remaining teeth. The samples were randomly divided into three groups, as follows: control group (without vertical root fracture), Super-Bond C&B group (fragments were attached with Super-Bond C&B), and self-adhesive dual-cured resin cement group (fragments were attached with self-adhesive dual-cured resin cement). Each specimen was subjected to a fracture resistance test, and data were statistically analyzed using chi-squared test, one-way ANOVA and post hoc Tukey tests (P=0.05). Results. The fracture resistance values of the control and Super-Bond C&B groups were higher than those of the self-adhesive dual-cured resin cement group (P<0.05). However, there were no significant differences between the control and Super-Bond C&B groups (P>0.05). Conclusion. Within the limitations of the present study, Super-Bond C&B was beneficial in obtaining higher fracture resistance in endodontically treated roots with vertical root fracture.

Effect of polymerization cycles on flexural strengths and microhardness of different denture base materials.

The purpose of this study was to evaluate the effect of different polymerization cycles on the flexural strengths and microhardness of two denture base materials (Meliodent and Paladent). Heat-polymerized acrylic resin specimens (65.0 mm long×10.0 mm wide×2.5 mm in height) were prepared using different short and long polymerization cycles. After the specimens had been polymerized, they were stored in distilled water at 37±1°C for 24 h. Flexural strength test was performed at a cross-head speed of 5 mm/min and Vickers microhardness was measured. Data were analyzed with a 1-way analysis of variance followed by Tukey test, and Student t-test (α=0.05). The flexural strengths and microhardness were significantly different between Meliodent and Paladent (p<0.05). Significant differences were found among the polymerization cycles in terms of flexural strengths and microhardness (p<0.05). Polymerization with G cycle may be suggested for Meliodent and H cycle may be suggested for Paladent.

Effects of multiple firings on the microstructure of zirconia and veneering ceramics.

The aim of study was to evaluate the effects of multiple firings on the microstructures of zirconia and two ceramics. Vita VM9 (VMZ) and Cerabien ZR (C-Z) ceramics on a zirconia framework and zirconia without veneering ceramic (WO-Z) were evaluated. Firing methods included firing two, five, and ten times (n=10). The effects of multiple firings on the surface hardness of the materials were evaluated using a Vickers hardness (HV) tester. Data were analyzed by two-way ANOVA and Tukey's test (α=0.05). After firing five and ten times, the hardness of VM-Z and C-Z increased significantly (p<0.001). The HVs of the Cerabien ZR and Vita VM9 veneering ceramics were similar (p>0.05). In the XRD analysis, zirconia had similar tetragonal (t)-monoclinic (m) phase transformations of Y-TZP after the different firing times. Clinically, multiple firings did not affect the microstructure of zirconia, but the structures of the two ceramics were affected.

Effect of repair resin type and surface treatment on the repair strength of polyamide denture base resin.

The purpose of the present study was to evaluate the effects of different repair resins and surface treatments on the repair strength of a polyamide denture base material. Polyamide resin specimens were prepared and divided into nine groups according to the surface treatments and repair materials. The flexural strengths were measured with a 3-point bending test. Data were analyzed with a 2-way analysis of variance, and the post-hoc Tukey test (α=0.05). The effects of the surface treatments on the surface of the polyamide resin were examined using scanning electron microscopy. The repair resins and surface treatments significantly affected the repair strength of the polyamide denture base material (p<0.05); however, no significant differences were observed interaction between the factors (p>0.05). The flexural strength of the specimens repaired with the polyamide resin was significantly higher than that of those repaired with the heat-polymerized and autopolymerizing acrylic resins.