Purpose: To determine whether post-menopausal women with a history of bisphosphonate use are at greater risk for implant failure or osteonecrosis of the jaw (ONJ) than an age- and gender-matched population with no history of bisphosphonate use.
Methods: A retrospective chart review and phone interview was conducted of patients seen at the Mayo Clinic who had implants placed after November 2006. Bisphosphonate users were identified by medical chart review. Dental implant survival and ONJ incidence were determined in a total of 82 post-menopausal non-bisphosphonate users and 55 post-menopausal bisphosphonate users using a phone interview. Implant failures were recorded and survival percentages were calculated for comparison.
Results: ONJ was not observed consequent to implant placement in any of the bisphosphonate users or non-users. In non-users, 163 out of 166 implants were surviving for a cumulative survival rate of 98.19%. In bisphosphonate users, 120 out of 121 implants were surviving for a cumulative survival rate of 99.17%.
Conclusion: Dental implants placed in post-menopausal women have the same survival potential regardless of whether patients have a history of bisphosphonate use. Bisphosphonate users who undergo dental implant surgery are at low risk for osteonecrosis of the jaw and a bisphosphonate “drug holiday” is not indicated in these patients.

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Purpose: To assess the influence of mandibular residual ridge resorption (RRR) on objective masticatory measures of two occlusal schemes: lingualized occlusion (LO) and fully bilateral balanced articulation (FBBA).
Methods: The enrolled patients (n = 22) were randomly allocated one set of complete dentures with either LO or FBBA. Maximum occlusal force, masticatory performance (by the MPI), and mandibular movements were measured at 3- and 6-month follow-ups. Mandibular RRR was assessed as the sum of the mandibular bone height at the midline, first premolar region, and least vertical height region, and from the mental foramen to the alveolar crest, measured on panoramic radiographs; the treatment groups were subclassified into severe or moderate RRR subgroups by the value of the sum of individual measurements.
Results: Significant differences were observed in the between-subgroup comparisons (Kruskal–Wallis test) of the MPI (3 months, p = 0.01; 6 months, p = 0.04) and linear deviation from intercuspal position (anterior–posterior: 6 months, p = 0.01; inferior–superior: 3 months, p = 0.008; 6 months, p = 0.02). The patients with severe RRR in the FBBA group showed a significant decrease in the MPI and increase in linear inferior deviation from intercuspal position at 3 months (post hoc comparison) as well as a significant increase in the linear posterior and inferior deviation from intercuspal position at 6 months.
Conclusions: LO is the preferable occlusal scheme for patients with severe RRR. (This trial has been registered at http://clinicaltrials.gov/ct2/show/NCT00959530.)

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Purpose: The purpose of the present study was to evaluate the flexural strength of the joint between glass-infiltrated alumina frames and the experimental adjusting agent (MA modifier) that contains alumina and magnesia.
Methods: A commercially available adjusting agent (Optimizer), a slurry of alumina powder (Alumina modifier), and a bulk specimen (joint-free alumina) were used as controls. Beam-shaped alumina specimens were machined from an alumina block. The ends of two alumina beams were positioned at an interval of 1.0 mm and joined with each adjusting agent. The joined specimens were subjected to sintering, glass infiltration firing, glass control firing, and then a three-point bending test was carried out to evaluate the flexural strength.
Results: The maximum flexural strength was observed in the joint-free alumina, followed by MA modifier, Optimizer and Alumina modifier. With the exception for joint-free alumina, the failure modes after three-point bending test tended to shift from adhesive failure at substrate material-adjusting agent interface to cohesive failure within adjusting agent as the flexural strength increased.
Conclusions: The use of MA modifier significantly improved the flexural strength of joined glass-infiltrated alumina frame. The MA modifier could be applied for adjusting the margin as an alternative to Optimizer when fabricating crown and bridge substructures with In-Ceram Alumina system.

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Purpose: This study aimed to evaluate the effect of different storage periods in artificial saliva and thermal cycling on Knoop hardness of 8 commercial brands of resin denture teeth.
Methods: Eigth different brands of resin denture teeth were evaluated (Artplus group, Biolux group, Biotone IPN group, Myerson group, SR Orthosit group, Trilux group, Trubyte Biotone group, and Vipi Dent Plus group). Twenty-four teeth of each brand had their occlusal surfaces ground flat and were embedded in autopolymerized acrylic resin. After polishing, the teeth were submitted to different conditions: (1) immersion in distilled water at 37 ± 2 °C for 48 ± 2 h (control); (2) storage in artificial saliva at 37 ± 2 °C for 15, 30 and 60 days, and (3) thermal cycling between 5 and 55 °C with 30-s dwell times for 5000 cycles. Knoop hardness test was performed after each condition. Data were analyzed with two-way ANOVA and Tukey's test (α = .05).
Results: In general, SR Orthosit group presented the highest statistically significant Knoop hardness value while Myerson group exhibited the smallest statistically significant mean (P < .05) in the control period, after thermal cycling, and after all storage periods. The Knoop hardness means obtained before thermal cycling procedure (20.34 ± 4.45 KHN) were statistically higher than those reached after thermal cycling (19.77 ± 4.13 KHN). All brands of resin denture teeth were significantly softened after storage period in artificial saliva.
Conclusion: Storage in saliva and thermal cycling significantly reduced the Knoop hardness of the resin denture teeth. SR Orthosit denture teeth showed the highest Knoop hardness values regardless the condition tested.

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Purpose: The aim of this study was to examine the influence of repetitive saliva-swallowing for the level of oral moisture using an oral-moisture checking device.
Methods: Subjects were 24 healthy adults (HA) and 20 patients with oral dryness, 10 of whom had Sjögren syndrome or who had undergone radiation therapy (ODSR) and 10 who had not experienced ODSR (ODNSR). Oral moisture was measured before swallowing saliva (B), and after swallowing saliva once (F), twice (S), and three times (T). Oral moisture was measured at the lingual mucosa using an oral-moisture checking device. Statistical analysis was performed using the Friedman test.
Results: Oral moisture of the lingual mucosa of the HA differed significantly between B and T, and F and T, and the oral moisture level tended to be higher the more times saliva was swallowed. However, oral moisture of lingual mucosa in the ODSR was not different at the different times of measurement, but the level of oral moisture tended to be lower the more times saliva was swallowed. Oral moisture of the lingual mucosa in the ODNSR differed significantly between B and T. The trends for the changes of the oral moisture level in the ODNSR were similar to those in the HA.
Conclusions: The results of this study show that swallowing saliva repeatedly could lead the increase of oral moisture in HA and ODNSR not in ODSR.

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Purpose: There is no clear evidence of the factors that could improve implant biomechanics in the posterior maxilla. Thus, a finite element analysis was performed to investigate the effect of maxillary cortical bone thickness, implant design and diameter on stress around implants.
Methods: A total of 12 models of the posterior maxilla with implant were computer-simulated by varying the thickness of the alveolar cortical bone (1.5, 1.0, 0.5 or 0 mm) and implant characteristics (cylindrical implant of 4.1-mm diameter, screw-type implants of 4.1-mm or 4.8-mm outer diameters). On top of each implant, forces were separately applied axially (100 N) and buccolingually (50 N), and the von Mises stresses were calculated.
Results: Regardless of load direction, implant design and diameter, cortical and cancellous bone stresses increased with the decrease of crestal cortical bone thickness. In the absence of crestal cortical bone, cancellous bone stresses were highest and, under axial load, were transferred to the sinus floor. Implant design and diameter influenced stress to a less extent, especially under buccolingual load and in the presence of crestal cortical bone.
Conclusions: From a biomechanical viewpoint, to improve implant success odds in the posterior maxilla, rather than implant selection, careful preoperative evaluation of the cortical bone at the planned implant site is recommended. If this cortical bone is very thin or even lacking, implant treatment should be carried on with caution by progressive loading in the range of functional loads.

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Patient: This report describes the longevity of a resin-bonded fixed partial denture (RBFPD). This denture was seated on the maxillary anterior teeth with minimal tooth preparation. The RBFPD was cast from a silver–palladium alloy (Castwell M.C. 12), and the pontic was veneered with an indirect composite material (Estenia). The retainers were primed with a metal conditioner (V-Primer) and seated with a tri-n-butylborane initiated adhesive resin (Super-Bond C&B). After an observation period of eight years, a fracture occurred in the incisal edge of the central incisor abutment. The fractured area was restored with light-polymerizing composite resin and the anterior guidance was re-adjusted.
Discussion: RBFPD abutment teeth with deep vertical overlap should be carefully prepared to avoid abutment tooth fracture.
Conclusion: The clinical performance of the RBFPD made from a silver–palladium–copper–gold alloy was sufficient when seated with tri-n-butylborane initiated adhesive resin after surface modification using vinyl-thiol primer.
Clinical significance: The use of vinyl-thiol primer and tri-n-butylborane initiated adhesive resin is a clinically reliable bonding system for seating resin-bonded fixed partial denture (RBFPD) made from a silver–palladium–copper–gold alloy. The RBFPD, based on a reliable bonding system, can clinically function for a long time, even if the vertical overlap of the abutment teeth is excessive.

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Purpose: This paper demonstrates a simple method using sacrificial protection for preventing the corrosion of dental metals.
Methods: Dental metals are directly connected or/and wound with a pure commercial aluminum/zinc wire/plate with high ionization tendency, before their immersion into oxidizing functional water.
Conclusion: Dental materials such as Co–Cr alloy wires, stainless steel, and Au–Ag–Pd alloys did not corrode when this method was used. Thus, this method is very simple and effective for preventing corrosion of dental metals during disinfection using functional water.

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