Antibacterial properties of nitric oxide-releasing porous silicon nanoparticles.

In this study, the antibacterial efficacy of NO-releasing porous silicon nanoparticles (pSiNPs) is reported. NO-releasing pSiNPs were produced via the conjugation of S-nitrosothiol (SNO) and S-nitrosoglutathione (GSNO) donors to the nanoparticle surfaces. The release of the conjugated NO caused by the decomposition of the conjugated SNO and GSNO was boosted in the presence of ascorbic acid. The released NO was bactericidal to Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli), and eliminated bacterial growth within 2 h of incubation without compromising the viability of mammalian cells. These results demonstrate the advantages of NO-releasing pSiNPs for antibacterial applications, for example, in chronic wound treatment.

Small interfering RNA delivery by polyethylenimine-functionalised porous silicon nanoparticles.

In this study, thermally hydrocarbonised porous silicon nanoparticles (THCpSiNPs) capped with polyethylenimine (PEI) were fabricated, and their potential for small interfering RNA (siRNA) delivery was investigated in an in vitro glioblastoma model. PEI coating following siRNA loading enhanced the sustained release of siRNA, and suppressed burst release effects. The positively-charged surface improved the internalisation of the nanoparticles across the cell membrane. THCpSiNP-mediated siRNA delivery reduced mRNA expression of the MRP1 gene, linked to the resistence of glioblastoma to chemotherapy, by 63% and reduced MRP1-protein levels by 70%. MRP1 siRNA loaded nanoparticles did not induce cytotoxicity in glioblastoma cells, but markedly reduced cell proliferation. In summary, the results demonstrated that non-cytotoxic cationic THCpSiNPs are promising vehicles for therapeutic siRNA delivery.

Comparison of partial and full crowns as retainers in the same bridge.

The purpose of this study was to assess longitudinally the success of partial and full crown abutment pairs in the same bridges. Fifty patients with a mean age of 45 years (range 22-70 years) were examined during spring 1981 (1-5 year follow-up), 33 of whom were examined a second time during spring 1990 (10-15 year follow-up). The status of the partial crowns, full crowns, and their abutment teeth was assessed using standardized questions, and clinical and radiographic examinations. At the first follow-up examination, all partial and full crowns, and consequently all bridges, were still in use. Before the second follow-up examination one of the full crown abutments had become badly decayed, and the bridge, including the partial crown, had been removed. The failure rate was 0.2% per year for the full crown as a unit, and consequently 0.2% per year for the bridge as a unit.

Radiographic signs in the TMJ and finger joints in elderly people.

Radiographic signs in the temporomandibular joints (TMJs) and finger joints were investigated in a series of 139 residents of elderly people's homes using panoramic tomographs and dorso-volar radiographs. Radiographic signs in TMJs were found in 14% of the subjects, whereas all subjects had signs in at least one finger joint. The TMJs of men and women were equally affected, whereas signs in finger joints were more severe in women. No correlation was found between radiographic signs in TMJs and finger joints, suggesting that most signs in TMJs are probably due to local factors.

Association between salivary flow rate and the use of systemic medication among 76-, 81-, and 86-year-old inhabitants in Helsinki, Finland.

The aim of this study was to examine salivary flow rate and its association with the use of medication in a representative sample of 76-, 81-, and 86-year-old subjects, totaling 368. In this study, 23% (n = 80) of the subjects were unmedicated. From one to three daily medications were used by 47% (n = 168) and more than four medications by 30% (n = 104). The most commonly used medications were nitrates, digitalis or anti-arrhythmic drugs (47.7%), analgesics and antipyretics (32.6%), and diuretics (29.5%). The mean number used daily was significantly higher in 86-year-olds than in the two younger age groups (p < 0.01). No significant differences in this respect were found between genders. Among the unmedicated subjects, 76-year-olds had significantly higher stimulated salivary flow rates than did the 81-year-olds (p < 0.05). Unmedicated women showed significantly lower unstimulated (p < 0.01) and stimulated flow rates than did men (p < 0.05). Stimulated salivary flow rate was also significantly higher in the 76-year-old medicated subjects than in the medicated 86-year-old subjects (p < 0.05). No statistically significant differences were found in unstimulated salivary flow rates among the three age groups. Medicated women showed significantly lower unstimulated salivary flow rates than men (p < 0.001), although the difference in stimulated saliva flow was not significant. A statistically significant difference in unstimulated and stimulated salivary flow rates was found between unmedicated persons and those who took from four to six, or more than seven, prescribed medications daily.

Treatment of xerostomia through use of dentures containing reservoirs of saliva substitute.

A 53-year-old woman was referred to the University Dental Clinic because of ocular and oral dryness during the previous year. She also had urticaria and was receiving medication for postmenopausal hormonal problems. The patient was wearing full dentures. Resting saliva flow rate (RSFR) and stimulated saliva flow rate (SSFR) were 0 ml/5 minutes and 0.5 ml/10 minutes, respectively. The patient was given Sulfarlem (trithioparamethoxyphenylpropene), tablets (25 mg) for six months. There was no significant improvement in flow rate. Medication was terminated as ineffective. Seven months later, full dentures with reservoirs of saliva substitute were constructed according to Vissink. The reservoir of the upper denture functioned satisfactorily for two weeks, after which the latex membrane valve became detached. The valve system was replaced with a Gerber matrix housing, which functions even without a latex membrane. The dentures were further improved by making a stainless steel plug constructed from a burr fitting into the matrix housing. This was found to effective in reducing the discharge of saliva substitute from the reservoir. Symptomatic treatment may be the treatment of choice in cases of xerostomia where no functional salivary gland tissue is present.

Craniomandibular disorders in elderly with psoriasis.

A questionnaire survey was carried out to determine the prevalence of craniomandibular (CM) disorders in relation to age in psoriasis. Of the 1776 psoriatics, 85.4% responded; 1050 of them had psoriasis with skin symptoms only (P), and 400 had both skin and joint symptoms (PA). No statistically significant differences could be found between older (greater than or equal to 65 yrs) and younger (less than 65 yrs) psoriatics in either the P-group or the PA-group as regards the severity of subjective symptoms of CM disorders. In the P-group the younger psoriatics reported more frequent (30%) subjective symptoms than the older ones did (19%) (p less than 0.05), but no difference was found in the PA-group (51% and 41%, respectively) (NS). The most frequently reported symptoms in all age groups were temporomandibular joint (TMJ) sounds and TMJ pain during function. TMJ sounds were significantly less frequently reported by the older than the younger psoriatics both in the P-group and the PA-group (p less than 0.01 and p less than 0.05, respectively). It can be concluded that, apart from TMJ sounds, the frequency and severity of symptoms of CM disorders are not related to age in psoriasis.

Leukocyte count and keratinization of the palatal denture-bearing mucosa.

The clinical and cytological effects of denture wear on the underlying palatal mucosa were studied in 67 complete denture patients. Forty-four persons without dentures served as the control group. Palatal keratinization under dentures was lower than the keratinization in the control group. Continuous denture wear, compared to daytime wear only did not reduce palatal keratinization. The appearance of leukocytes in smears from the palatal mucosa was related to the degree of mucosal keratinization but not to denture-wearing habits.

Milk and vegetables in the diet of institutionalized elderly people in Finland.

More than 95% of the institutionalized elderly subjects drank milk, and more than 50% ate raw vegetables one or more times a day. There were no statistical differences between the frequencies of men and women, and the mean frequency index for age groups 65 to 74, 75 to 84, and greater than or equal to 85 years was the same for milk throughout. For vegetables, the mean value rose slightly toward to older age groups. More than half of the edentulous denture wearers and of the dentulous subjects ate raw vegetables every day, while only 38% of the edentulous without dentures did. The availability of vegetables alone is not enough; the intake of these vegetables must be actively encouraged.

Clinical study of a heat-cured silicone soft lining material.

Thirty-seven mandibular dentures lined with Molloplast B silicone material were examined after they had been worn for 2-8 weeks and 6, 18 and 30 months. The denture wearers were also examined and interviewed. The colour was found to have become lighter in 46% and turned yellow or brown in 51%; the denture base had worn through in 24% and there was a failure on bond in 22%; no hardening of the material was noted; 24% of the dentures had broken. An unusual taste was reported by 22% and smell by 14% of the denture wearers; mucosal soreness was noted in 14%; denture stomatitis developed in 48%; hygiene was poor in 61% and fungal growth was traced in 81% of the dentures; 73% of the patients were satisfied with the soft lining.

Frequency of mandibular dysfunction symptoms in institutionalized elderly people.

Mandibular dysfunction symptoms were found in 74% of 375 elderly persons, aged 65 or over, 79% of the women and 59% of the men (p less than 0.001). 36% had one symptom, 26% two symptoms, 8.5% three symptoms, and 3% 4--5 symptoms. The most frequent were the temporomandibular joint (TMJ) sounds (48%). Deviation of mandible on opening and/or closing movement was found in 44%, in women more often than men (p less than 0.05). The frequency of limited opening was 14%, higher among women than men (p less than 0.05). Tenderness to palpation laterally over the TMJ was observed in 14%. 7% reported pain on opening movement, women more often than men (p less than 0.01).