Some aspects of the orthodontic-prosthetic approach for adult patients. A case report

Authors present a case report of an adult patient treated with the combination of orthodontic and prosthetic treatment methods. The importance of periodontal and psychological management of such patients is pointed out.     

Effects of phosphoric acid on bovine enamel bleached with carbamide peroxide

The aim of this study was to measure the demineralization capacity of 37% phosphoric acid on bovine enamel at different time-points after bleaching with 30% carbamide peroxide. Five, 4 × 4-mm sections were obtained from the enamel of 10 bovine incisors. After applying 30% carbamide peroxide (Vivastyle) for 90 min, specimens were stored in artificial saliva for 0, 24, 72 h, or 7 d and then immersed in 37% phosphoric solution. At 15, 30, 60, 90, and 120 s, 5-ml aliquots were extracted. A control group of specimens was not bleached. Ca²⁺ concentrations were measured by atomic absorption spectrophotometry. A larger amount of Ca²⁺ was extracted from enamel by phosphoric acid after the application of 30% carbamide peroxide. Twenty-four hours after bleaching, significantly more Ca²⁺ was extracted from bleached than from control specimens at all time-points, and this greater susceptibility to the action of the acid persisted for at least 1 wk after bleaching.     

Bactericidal effect of Er,Cr:YSGG laser on Streptococcus mutans

The aim of this study was to compare the antibacterial activities of Er,Cr:YSGG laser with two different power outputs against a chlorhexidine gluconate-based cavity disinfectant. A cavity tooth model test was used to determine the antibacterial activity. Four cylindrical cavities were prepared on the dentin surface of 10 bovine incisors and left in contact with Streptococcus mutans for 72 hours to allow bacterial invasion. Following which, Er,Cr:YSGG laser with 0.75 W and 1 W power outputs and a chlorhexidine gluconate-based cavity disinfectant were applied separately on one of the three infected cavities, whereas the fourth was left untreated for control. Standardized amounts of dentin chips were obtained from the cavity walls, and the number of bacteria recovered was counted. Statistical analysis was carried out using one-way ANOVA and Dunnett's C test (p=0.05). No significant differences were observed among the data obtained from the chlorhexidine gluconate-based cavity disinfectant and the two Er,Cr:YSGG laser groups (p>0.05). However, when compared to the control group, both Er,Cr:YSGG laser groups and the chlorhexidine gluconate-based cavity disinfectant resulted in significantly less bacterial recovery (p<0.05). In conclusion, the antibacterial activity on S. mutans demonstrated by Er,Cr:YSGG laser with both energy outputs was similar to that of the tested chlorhexidine gluconate-based cavity disinfectant.     

Specific antibodies against Actinobacillus actinomycetemcomitans in serum and saliva of patients with advanced periodontitis

The aim of the present study was to discover any possible correlation between specific antibodies against Actinobacillus actinomycetemcomitans (A.a.) in serum and saliva. The test group consisted of 38 patients aged 31–68 yr (mean 49) with advanced periodontitis. Twenty-nine subjects aged 23–67 yr, without periodontal destruction, formed a control group with a reference level of specific salivary antibodies against A.a. A subgingival plaque sample for culturing A.a. , a specimen of stimulated whole saliva, and a sample of venous blood were taken from each subject of the test group. Specific IgG and IgA antibodies against A.a. were determined from serum and stimulated whole saliva by means of the ELISA test. Fifteen of the patients (39%) had cultivable A.a. Six of the 15 A.a. culture-positive patients and one of the 29 reference subjects exhibited very high antibody titers against A.a. in saliva. Specific IgG and IgA antibodies in saliva correlated highly significantly with the corresponding antibody values in serum among the patients in the test group. It was concluded that among patients with severe adult periodontitis, the less invasive saliva sample has a diagnostic value equal to that of the serum sample concerning specific antibodies against A.a.     

Oral and intestinal microflora in 5‐fluorouracil treated rats,translocation to cervical and mesenteric lymph nodes and effects of probiotic bacteria

Serious systemic infections may occur during cancer chemotherapy due to disturbances in the oropharyngeal and gastrointestinal microflora, impaired mucosal barrier functions and immunosuppression. Bacteria may spread from the gastrointestinal tract to the regional lymph nodes. The routes for bacterial spread from the oral cavity are less well known. In the present study we investigated changes in the oral and intestinal microfloras in rats given 50 mg/kg 5‐fluorouracil (5‐FU) i.v. for 6 days. Bacterial dissemination to the lymph nodes draining the oral cavity and the lymph nodes draining the gastrointestinal tract was examined. Effects of adding the probiotic strain Lactobacillus plantarum 299v in the drinking water to the rats were measured. 5‐FU treatment caused an increase in the number of facultative and strictly anaerobic bacteria in biopsies from the oral cavity and an increase in the number of facultative anaerobes in the large intestine. The proportion of facultative gram‐negative rods increased in both the oral cavity and intestine. Bacteria translocated to both the cervical and mesenteric lymph nodes in untreated animals and increased in numbers after 5‐FU treatment due to an increase in the number of facultative gram‐negative rods. Treatment with L. plantarum 299v improved food intake and body weight in 5‐FU‐treated rats. It also reduced the 5‐FU‐induced raise in the total numbers of facultative anaerobes in the intestine, but did not reduce translocation and did not prevent diarrhea. This study reinforces the oral cavity, along with the gastrointestinal tract, as a source for bacterial dissemination. The use of probiotic bacteria may reduce some side effects of 5‐FU treatment.     

Peripheral T-cell subsets in patients with reticular and atrophic-erosive oral lichen planus

OBJECTIVE: Oral lichen planus (OLP) presents with various clinical forms that can be classified into 2 major types: reticular OLP and atrophic-erosive OLP. Our objective was to investigate immunologic differences between these 2 types. STUDY DESIGN: We investigated possible immunologic differences between 26 patients with reticular OLP and 26 patients with atrophic-erosive OLP. RESULTS: No differences were detected in serum Ig levels or complement levels. However, the mean proportions of CD4+CD45RO+ and DR+ lymphocytes were significantly higher in patients with atrophic-erosive OLP than in patients with reticular OLP, whereas the mean proportion of CD8+CD45RA+ lymphocytes was significantly lower in patients with atrophic-erosive OLP. CONCLUSION: These findings suggest that the 2 clinical types of OLP might have different immunopathogenic mechanisms.     

Delayed healing of fractures of the mandibular body

401 mandibular body fractures occurring during a 5-year period were analysed retrospectively. Out of these, 38 fractures (9.5%) were not consolidated by 50 days and made up the delayed healing group (DHG). A control group (CG) of another 38 fractures was constituted using the first mandibular body fracture consecutively following one in the DHG. The mean time until consolidation of the fractures was 116 days in the DHG and 35 days in the CG. The 2 groups were statistically analysed and mutually compared using a great number of variables including patient-, fracture site-, treatment- and end-result characteristics. It was concluded that a few days delay between trauma and treatment did not necessarily lead to a delayed healing. Uncooperative alcoholics with psycho-social handicaps, and general as well as local periodontitis, were found to be especially liable to consolidate their fractures at a slower rate than the average patient. The DHG more often required changes of unstable dental fixation, prolonged maxillo-mandibular fixation time and treatment for late infections at the fracture site. The patients in this group lost more teeth than those in the CG but above all required considerably extended therapeutic efforts. It is suggested that patients with the above-mentioned characteristics should be given special attention and care.     

Trigeminal neuropathy

Trigeminal neuropathies (TNs) are well recognized disorders characterized and manifesting as skin and mucosal numbness in the region innervated by the trigeminal nerve. Facial numbness indicates trigeminal sensory alteration affecting the trigeminal system. TNs always pose differential location difficulties as multiple diseases are capable of producing them: they can be the result of traumatism, tumors, or diseases of the connective tissue, infectious or demyelinating diseases, or may be of idiopathic origin. Their importance is explained by the fact that TN may represent the first manifestation of tumor disease, or of relapse in patients with prior neoplastic processes. As such, these manifestations are ominous, and patient life expectancy is often short. The clinical exploration reveals a loss of sensitivity in the cutaneous territory corresponding to the affected nerve, which can be partial (hypoesthesia) or complete (anesthesia). The sensory defect is occasionally associated with hyperesthesia (i.e., the patient suffers a decrease in sensory perception, but when sensation is perceived, it may cause considerable discomfort). Complementary studies are needed to establish the etiologic diagnosis, with laboratory tests to discard the possible causative diseases underlying the trigeminal neuropathy, and the opportune radiographic examinations in the form of plain X-rays or a routine cranial computed tomography scan.     

Histomorphometric and removal torque analysis for TiO2-blasted titanium implants. An experimental study on dogs

The aim of the present study was to compare the anchorage of TiO2-blasted screw and cylindrical implants with conventionally used machine-produced screw and cylindrical implants inserted immediately in extraction sockets on dogs. 6 adult mongrel dogs had 3rd and 4th mandibular premolars extracted bilaterally and 24 commercial pure titanium implants were placed immediately in extraction sockets and covered with mucoperiosteum. Each dog had inserted 4 implants: 1 screw implant and 1 cylindrical implant blasted with titanium-dioxide-particles; 1 screw implant and 1 cylindrical implant with machine-produced (m.p.) surface (controls). After a healing period of 12 weeks, 16 implants from 4 animals were used for removal torque test, which demonstrated that significantly higher removal torque force was needed to unscrew the implants blasted with titanium-dioxide-particles, than the normal m.p. implants. The medians for the TiO2-blasted screw and cylindrical implants were > 150 Ncm and 105 Ncm, respectively, while the values for the m.p. implants were 60 Ncm and 35 Ncm, respectively. The SEM investigation demonstrated a high irregularity of the TiO2-blasted surface compared to the machined surface. The Ra and Rz values for surface roughness were higher for the TiO2-blasted implants than for the normal m.p. implants. Histomorphometrically, the arithmetic mean of the direct bone-implant contact fraction was 69%. There was no significant difference in direct bone-implant contact length fraction between TiO2-blasted implants and the control implants. The implants blasted with titanium-dioxide-particles in this study showed a better anchorage than implants with a machine-produced surface. The screw implants showed a better anchorage than the cylindrical implants.     

Laser-induced fluorescence from sound and carious tooth substance: spectroscopic studies

Fluorescence spectra of dentine and enamel illuminated with laser light of wavelengths of 337, 488, 515 and 633 nm respectively were recorded. The fluorescence obtained by illumination with UV laser light at 337 nm had a peak at about 400 nm in dentine as well as enamel. Compared to intact enamel the fluorescence from enamel with initial carious lesions was of lower intensity and had a slight red shift. No fluorescence within the visible range was obtained by illumination with a low power He-Ne laser at 633 nm. Illumination at 488 nm produced fluorescence with a peak at about 540 nm in dentine as well as enamel. The difference in the intensity of fluorescence between sound and carious enamel was generally greater at this wavelength than at any of the others tried, and the red shift from the carious enamel was also more pronounced. Illumination at 515 nm produced fluorescence of similar wavelengths but with much less difference between intact and carious enamel. It was concluded that illumination at 488 nm was the most suitable wavelength of those investigated for the detection of initial carious lesions by the fluorescence technique.