A preliminary report on patient acceptance of a novel intra-oral lubricating device for the management of radiotherapy-related xerostomia

Management of radiotherapy-related xerostomia is difficult. Saliva substitutes are helpful but the effects are short-lived. The purpose of the study was to develop a prototype intra-oral lubricating device for the management of radiotherapy-related xerostomia and to evaluate patient acceptance. An intra-oral lubricating device was fabricated that incorporated a reservoir in the palatal vault and permitted slow release of saliva substitute by the patient. Preliminary clinical testing was done in five patients with radiotherapy-related xerostomia. A measure incorporating seven questions was used to explore patient acceptance. The device was simple to fabricate using materials available in a technical laboratory. All patients were able to wear the device for at least 4 h per day throughout the test period. The device was considered easy to use and clean. Some impairment of speech and chewing was noted although this appeared to be related to the bulkiness of the reservoir. General oral comfort was improved due to the lubricating effect. The bulk of the reservoir was reduced as a consequence of patient feedback. The design addressed key problems associated with previous lubricating systems. Patient reports on oral functioning with the device in situ provided pivotal information on the devices utility.     

The influence of simulated masticatory loading regimes on the bi-axial flexure strength and reliability of a Y-TZP dental ceramic

OBJECTIVES: The purpose of the current study was to examine the influence of simulated masticatory loading regimes, to which all-ceramic crown or bridge restorations will routinely be subjected during their service-life, on the performance of a yttria-stabilised tetragonal zirconia polycrystalline (Y-TZP) dental ceramic. METHODS: Ten sets of 30 Y-TZP ceramic discs (13 mm diameter, 1.48-1.54 mm thickness) supplied by the manufacturer were randomly selected. Six groups were loaded for 2000 cycles at 500 N (383-420 MPa), 700N (536-588 MPa) and 800 N (613-672 MPa) with three groups maintained dry and the remaining three groups loaded while immersed in water at 37+/-1 degrees C. A further two groups underwent extended simulated masticatory loading regimes at 80 N (61-67 MPa) for 10(4) and 10(5)cycles under dry conditions. The mean bi-axial flexure strengths, standard deviations and associated Weibull moduli (m) were determined. The surface hardness was also determined using the Vickers hardness indentation technique. RESULTS: No significant difference (P>0.05) was identified in the bi-axial flexure strength of the simulated masticatory loading regimes and the control specimens loaded dry or wet. A significant increase in m was identified for the Y-TZP specimens following loading while immersed in water (8.6+/-1.6, 8.5+/-1.6 and 10.3+/-1.9) compared with the control (7.1+/-1.3). However, the extended loading regime to 10(5)cycles resulted in a significant reduction in the m of the Y-TZP specimens (5.3+/-1.0) compared with the control. Localised areas of increased surface hardness were identified to occur directly beneath the spherical indenter. CONCLUSIONS: The occurrence of localised areas of increased surface hardness could be the result of either a transformation toughening mechanism or crushing and densification of the material beneath the indentor manifested as the formation of a surface layer of compressive stresses that counteracted the tensile field generated at the tip of a propagating crack which increased the Weibull modulus of the Y-TZP specimens. The reduced reliability of the Y-TZP specimens loaded to 80 N for 10(5)cycles was associated with the accumulation of subcritical damage as a result of the extended nature of loading.     

Co-ordinated treatment of secondary cleft deformities

Secondary cleft deformities result from the cumulative effects of functional and morphological abnormalities. Treatment choices should be based on a comprehensive plan which is designed to minimize treatment time and iatrogenic effects and which is based on sound physical and psychosocial objectives. Conventional orthodontic and orthognathic surgical principles can be modified and applied to a variety of facial cleft problems. Direct surgical correction of secondary deformities instead of prosthetic or orthodontic compensation expands treatment possibilities and optimizes treatment results.     

Role of tonsillectomy in histology for adults with unilateral tonsillar enlargement

Unilateral tonsillar enlargement (UTE) may indicate malignancy. The purpose of this study was to evaluate the necessity of tonsillectomy for histological examination as a routine practice for every such case. We attempted to identify every adult who had tonsillectomy in our unit from January 1991 to January 2000 in whom the indication for operation was unilateral tonsillar enlargement. The case notes and pathology records were reviewed. One hundred and seven cases were identified but 9 case records could not be found, leaving 98 cases for analysis. Forty-eight were men and 50 were women, aged 16-85 (median age 32). Twenty-three malignancies were identified (23%). A high degree of clinical suspicion was noted pre-operatively in 37 cases, which included all 23 malignancies. Malignancy was more common in the presence of ulceration, male sex, lymphadenopathy, and age 45 years or more, and when it was the patient who first noticed the tonsillar enlargement. Current smoking and persistent pain were not significantly associated with malignancy. Night sweats and weight loss were uncommon. In many cases the apparent tonsillar enlargement was spurious due to asymmetry of the tonsillar pillars.     

Clinical,radiographic, histologic,and histomorphometric comparison of PepGen P-15 particulate and PepGen P-15 flow in extraction sockets: a same-mouth case study

PURPOSE: Although the efficacy of PepGen P-15 particulate has been conclusively demonstrated in two multicenter clinical studies, the effect of a new hydrogel formulation containing PepGen P-15 on bone repair has not been previously demonstrated. MATERIALS AND METHODS: PepGen P-15 Flow contains PepGen P-15 particulate in a biocompatible hydrogel, which provides spacing between the particles. In this case study, bone repair of both PepGen P-15 particles and PepGen P-15 Flow was compared to natural bone in same-mouth extraction sockets. RESULTS: The radiographic, histologic, and histomorphometric evaluations showed enhanced bone formation and faster particle resorption with PepGen P-15 Flow compared to the PepGen P-15 particulate. CONCLUSION: The accelerated bone formation by PepGen P-15 Flow may provide faster implant placement.     

Adsorption from black tea and red wine onto in vitro salivary pellicles studied by ellipsometry

The adsorption of black tea and red wine components onto a pellicle-like protein layer formed in vitro by adsorption from whole unstimulated saliva on hydroxyapatite discs were studied by in situ ellipsometry. It was found that components from black tea readily adsorbed to the pellicle. Subsequent exposure to saliva led to further adsorption of salivary components to give an overall increase in the amounts adsorbed. The amounts adsorbed increased still further following a third tea and saliva exposure. Components of red wine gave significantly greater amounts of adsorption to the pellicle than black tea. The adsorption of components of black tea gave a concomitant increase in colour or stain as measured by a reflectance chromameter. In all cases, the black tea- and red wine-modified pellicles were not eluted by either phosphate buffer or sodium dodecyl sulphate (SDS) rinses. Thus, black tea and red wine components have been shown to have a profound effect on in vitro pellicle maturation, causing thickened layers of stained material to build up, which are not readily removed.     

Periodontal status in two siblings with severe congenital neutropenia: diagnosis and mutational analysis of the cases

BACKGROUND: Severe congenital neutropenia (SCN), also known as Kostmann syndrome, was originally reported as an autosomal recessive disease of neutrophil production. The disease is characterized by a maturation arrest of neutrophil precursors at the promyelocytic stage of differentiation and by extremely low levels of mature neutrophils in peripheral blood. METHODS: A 6-year-old male presented with a complaint of gingival swelling and bleeding, and swelling at the left side of his face. Upon clinical examination, severe inflammation of all gingival tissues was apparent, and a periapical abscess with mobility was noted on the left mandibular second molar. Medical and dental histories revealed numerous recurrent bacterial infections associated with oral and non-oral tissues. His medical history with recurrent infections led us to evaluate his 3-year-old sister to determine the status of her oral health. Inflammation of her oral tissues and recurrent bacterial infections were apparent. Their consanguineous parents were in good health. To assist in identifying possible systemic diseases underlying the inflammatory situation in the siblings, consultations were requested from the Pediatric Hematology Department at Selcuk University and Pediatric Oncology Department at Gulhane Military Medical Academy. RESULTS: Based on absolute neutrophil count (< or =200/mm(3)) and bone marrow aspiration findings consistent with early maturation arrest in myelopoiesis, the cases were diagnosed as SCN. No chromosomal abnormality was detected upon cytogenetic examination. Sequencing analysis also revealed no mutation in the neutrophil elastase or growth factor independent-1 (GFI-1) genes in these patients. Severe periodontal disease, attachment loss, and mobility for over 50% of the deciduous teeth were noted. Within 6 months, the male sibling lost all of his deciduous teeth due to periapical and periodontal infections. His sister presented with tooth mobility for all mandibular incisors. Monthly visits, including scaling, polishing, and 0.2% chlorhexidine digluconate irrigation were performed to support their oral hygiene and to avoid recurrent oral infections. We have been able to stabilize these patients' periodontal conditions during a 2-year follow-up period. CONCLUSION: This case report emphasizes the role of periodontists and pediatric dentists in the diagnosis of diseases linked with neutrophil and other systemic disorders and highlights the need to optimize the health of oral tissues with regular appointments.     

Effect of Heat Treatment on Joint Properties of Laser-Welded Ag-Au-Cu-Pd and Co-Cr Alloys

PURPOSE: This study investigated the effect of heat treatment on the strengths of laser-welded cast Ag-Au-Cu-Pd and Co-Cr alloys. MATERIALS AND METHODS: Cast plates of Ag-Au-Cu-Pd (Ag) and Co-Cr (Co) alloys were prepared. After polishing the surfaces to be welded, the plates were matched and butted Ag to Ag (Ag/Ag), Co to Co (Co/Co), and Ag to Co (Ag/Co) and welded using Nd:YAG laser at a pulse duration of 10 ms, spot diameter of 1 mm, and voltage of 200 V. Five specimens were prepared for each experimental condition by bilaterally welding them with five spots. The Ag/Ag, Ag/Co, and control Ag underwent two heat treatments-softening (ST) and hardening (AH). A group of as-cast specimens serving as controls was not given either heat treatment. The failure load and percent elongation were measured at a crosshead speed of 1.0 mm/min. RESULTS: The fracture resistance of Co/Co was similar to that of the control Co, while the fracture resistance of Co/Ag was significantly lower than that of both like alloy pairings for all heat-treating conditions. The control Ag had greater fracture resistance after AH and lower fracture resistance after ST. The AH treatment increased the fracture resistance, and the ST treatment decreased the fracture resistance of both Ag/Ag and Co/Ag, although not significantly. The percentage of elongation appeared to positively correlate with the fracture resistance results. CONCLUSIONS: The results obtained in this study indicated that the age-hardening heat treatment increased the weld strength between the paired Au-Ag-Cu-Pd alloys and between the Au-Ag-Cu-Pd and Co-Cr alloys.     

A p38 mitogen-activated protein kinase inhibitor arrests active alveolar bone loss in a rat periodontitis model

BACKGROUND: Gram-negative bacterial species, such as Actinobacillus actinomycetemcomitans, contain lipopolysaccharide (LPS) that initiates the innate immune system, resulting in inflammatory alveolar bone loss. LPS activates Toll-like receptors on membrane surfaces, stimulating many intracellular signaling cascades, including the p38 mitogen-activated protein kinase (MAPK). Activation of p38 signaling mediates inflammatory cytokine expression, contributing toward osteoclastogenesis and bone loss. The aim of this study was to determine whether the novel, orally active p38 MAPK inhibitor SD282 could arrest progression of LPS-induced alveolar bone destruction in rats. METHODS: Three groups of female Sprague-Dawley rats received LPS injections to the palatal molar gingiva three times per week for 4 weeks to establish periodontitis. From weeks 5 through 8, two groups received the drug SD282 (N = 14) or 1% polyethylene glycol drug vehicle (N = 14) via oral gavage in addition to LPS injections. The third group continued to receive only LPS injections (N = 8). Microcomputed tomography was used to measure volumetric alveolar bone loss, expressed as bone volume fraction (BVF). Expression of interleukin (IL)-1 and -6 and tumor necrosis factor-alpha (TNF-alpha) was assessed by immunohistochemistry, and osteoclasts were enumerated by tartrate-resistant acid phosphatase staining. RESULTS: By 4 weeks, severe alveolar bone resorption was seen in LPS-injected animals. Administration of SD282 significantly blocked additional volumetric bone loss in the LPS-only versus LPS + SD282 groups (0.37 +/- 0.01 BVF versus 0.43 +/- 0.01 BVF; P < 0.01). Significant reductions in IL-1beta (P < 0.01 ), TNF-alpha (P < 0.05), and osteoclast formation (P < 0.01) occurred in the presence of SD282. CONCLUSIONS: An orally active p38 MAPK inhibitor reduced LPS-induced inflammatory cytokine expression, osteoclastogenesis, and alveolar bone loss in rats. Within the limits of the current study, SD282 arrested periodontal disease progression, thus highlighting the therapeutic potential of this novel class of inhibitors.