Clinical Evaluation of Zygomatic Implant-Supported Fixed and Removable Prosthesis.

The aim of our study was to present success and complication rates of 32 zygomatic implants (ZI) and compare satisfaction of patients rehabilitated with ZI supported hybrid prosthesis in atrophic jaws and removable prosthesis in maxillary defects. Sixteen patients who have been diagnosed as atrophic maxilla or maxillary defect were treated with ZI supported hybrid or removable prosthesis between 2008 and 2016 years, respectively. Thirty-two of 70 implants were placed in the zygomatic bone. Two prosthetic groups were compared 1 month after prosthesis delivery in terms of general satisfaction, stability, performance, esthetics, phonetics, hygiene level based on visual analog scale. Zygomatic implants success rate was found 93.7% after a mean follow-up of 28 ±â€Š22 months (range 6-96 months). Thirty of 32 ZIs have been functioning with their prosthesis. The rate of biologic complications related to ZIs was found 9.3% and prosthetic complication's rate related to ZI was 3%. Two early failures of ZIs were recorded. Chewing performance (P: 0.003), stability (P: 0.0001), and phonetics (P: 0.003) were found higher in hybrid prosthetic group. On the other hand, there was a statistically significant difference between groups in favor of removable prosthetic group regarding ease of cleaning (P: 0.007). Our study shows high success rate and minimal complications for 32 ZIs. This procedure seems to be an alternative to the bone grafts or sinus lifting techniques in patient of severely resorbed maxilla or to the obturator prosthesis for maxillectomy patients.

Polymerization efficiency of two dual-cure cements through dental ceramics.

PURPOSE: The aim of this study was to evaluate the effect of thickness of zirconia on curing efficiency of resin cements. MATERIALS AND METHODS: Four discs with 4.0 mm in diameter were prepared from non-HIP translucent zirconia blocks using a CAD/CAM system and feldspathic ceramic was layered onto discs. Thus, 4 ceramic disc samples were fabricated: (G) 0.5 mm zirconia- as a control group, (G1) 0.5 mm zirconia and 0.5 mm feldspathic, (G2) 1.0 mm zirconia and 0.5 mm feldspathic and (G3) 2.0 mm zirconia and 0.5 mm feldspathic ceramic layer. 2 different dual cure cements were polymerized using a LED curing unit. Degree of conversion was evaluated using Vickers Hardness Test and depths of cure of samples were measured. Data were analyzed statistically using One-way ANOVA and Tukey's HSD test (p<0.05). RESULTS: Microhardness and depth of cure values were different under same thickness of ceramic discs for two resin cements. As the thickness of the zirconia discs increased, the microhardness values and depth of cure decreased. CONCLUSION: Photocuring time cannot be the same for all clinical conditions, under thicker zirconia restorations (>2.0 mm), an extended period of light curing or a light unit with a high irradiance should be used.

Curing efficiency of dual-cure resin cement under zirconia with two different light curing units.

PURPOSE: Adequate polymerization is a crucial factor in obtaining optimal physical properties and a satisfying clinical performance from composite resin materials. The aim of this study was to evaluate the polymerization efficiency of dual-cure resin cement cured with two different light curing units under zirconia structures having differing thicknesses. MATERIALS AND METHODS: 4 zirconia discs framework in 4 mm diameter and in 0.5 mm, 1 mm and 1.5 mm thickness were prepared using computer-aided design system. One of the 0.5 mm-thick substructures was left as mono-layered whereas others were layered with feldspathic porcelain of same thickness and ceramic samples with 4 different thicknesses (0.5, 1, 1.5 and 2.0 mm) were prepared. For each group (n=12) resin cement was light cured in polytetrafluoroethylene molds using Light Emitting Diode (LED) or Quartz-Tungsten Halogen (QHT) light curing units under each of 4 zirconia based discs (n=96). The values of depth of cure (in mm) and the Vickers Hardness Number values (VHN) were evaluated for each specimen. RESULTS: The use of LED curing unit produced a greater depth of cure compared to QTH under ceramic discs with 0.5 and 1 mm thickness (p<0.05).At 100µm and 300 µm depth, the LED unit produced significantly greater VHN values compared to the QTH unit (p<0.05). At 500 µm depth, the difference between the VHN values of LED and QTH groups were not statistically significant. CONCLUSION: Light curing may not result in adequate resin cement polymerization under thick zirconia structures. LED light sources should be preferred over QTH for curing dual-cure resin cements, especially for those under thicker zirconia restorations.

The effects of pulsed electromagnetic field (PEMF) on osteoblast-like cells cultured on titanium and titanium-zirconium surfaces.

BACKGROUND: Commercially pure Ti, together with Ti Ni, Ti-6Al-4V, and Ti-6Al-7Nb alloys, are among the materials currently being used for this purpose. Titanium-zirconium (TiZr) has been developed that allows SLActive surface modification and that has comparable or better mechanical strength and improved biocompatibility compared with existing Ti alloys. Furthermore, approaches have targeted making the implant surface more hydrophilic, as with the Straumann SLActive surface, a modification of the SLA surface. PURPOSE: The aim of this study is to evaluate the effects of pulsed electromagnetic field (PEMF) to the behavior of neonatal rat calvarial osteoblast-like cells cultured on commercially pure titanium (cpTi) and titanium-zirconium alloy (TiZr) discs with hydrophilic surface properties. MATERIALS AND METHODS: Osteoblast cells were cultured on titanium and TiZr discs, and PEMF was applied. Cell proliferation rates, cell numbers, cell viability rates, alkaline phosphatase, and midkine (MK) levels were measured at 24 and 72 hours. RESULTS: At 24 hours, the number of cells was significantly higher in the TiZr group. At 72 hours, TiZr had a significantly higher number of cells when compared to SLActive, SLActive + PEMF, and machine surface + PEMF groups. At 24 hours, cell proliferation was significantly higher in the TiZr group than SLActive and TiZr + PEMF group. At 72 hours, TiZr group had higher proliferation rate than machine surface and TiZr + PEMF. Cell proliferation in the machine surface group was lower than both SLActive + PEMF and machine surface + PEMF. MK levels of PEMF-treated groups were lower than untreated groups for 72 hours. CONCLUSIONS: Our findings conclude that TiZr surfaces are similar to cpTi surfaces in terms of biocompatibility. However, PEMF application has a higher stimulative effect on cells cultured on cpTi surfaces when compared to TiZr.

Immediate implant placement without bone grafting: a retrospective study of 110 cases with 5 years of follow-up.

PURPOSE: Immediate implant placement not only reduces the number of surgeries necessary but also decreases the treatment time and treatment costs. The purpose of the study was to present the clinical results of 110 cases of immediate implant placement without using graft materials at the end of 5 years. MATERIALS AND METHODS: One hundred and ten implants in 72 patients were included in the study. Inclusion criteria for the patients were presence of at least 2 mm of bone beyond the root apex, the absence of acute signs of infection or inflammation in the treatment area, and the absence of systemic pathologies that would contraindicate bone healing around implants. In cases where bone grafting was necessary, the implant was excluded from the study. RESULTS: Healing progressed uneventfully in 105 cases. Four implants were lost as a result of infection in the first 3 months and 1 implant was lost 1 year after the functional loading of the prosthesis. The soft tissue anatomy was clinically acceptable in all patients. The implants that were placed in the extraction sockets of infectious teeth had also acceptable survival rates and clinical success. CONCLUSION: With proper patient selection, immediate implant placement without bone grafting has predictable survival rates and clinical success.