Collagen cross-linking, a major post-translational modification of collagen, plays important roles in the biological and biomechanical features of bone. Collagen cross-links can be divided into lysyl hydroxylase and lysyloxidase-mediated enzymatic immature divalent cross-links, mature trivalent pyridinoline and pyrrole cross-links, and glycation- or oxidation-induced non-enzymatic cross-links (advanced glycation end products) such as glucosepane and pentosidine. These types of cross-links differ in the mechanism of formation and in function. Material properties of newly synthesized collagen matrix may differ in tissue maturity and senescence from older matrix in terms of crosslink formation. Additionally, newly synthesized matrix in osteoporotic patients or diabetic patients may not necessarily be as well-made as age-matched healthy subjects. Data have accumulated that collagen cross-link formation affects not only the mineralization process but also microdamage formation. Consequently, collagen cross-linking is thought to affect the mechanical properties of bone. Furthermore, recent basic and clinical investigations of collagen cross-links seem to face a new era. For instance, serum or urine pentosidine levels are now being used to estimate future fracture risk in osteoporosis and diabetes. In this review, we describe age-related changes in collagen cross-links in bone and abnormalities of cross-links in osteoporosis and diabetes that have been reported in the literature.

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Purpose: This study aimed to establish a method for evaluating whether wearing dentures causes erythematous candidiasis, and to judge the necessity of eliminating Candida from the dentures. Therefore, the usefulness of microscopic observation of swabbed specimens from dentures was examined.
Method: Twenty-three cases, who were diagnosed as erythematous candidiasis clinically and who wore dentures (EC group), were included in this study. An additional nine cases of denture wearers served as a control (CTL group), who did not present clinical evidence of symptoms of candidiasis. Culture and microscopic examination were carried out for the detection of Candida. Because all cases in the EC group had a tongue lesion, samples were collected from the surface of the dorsum of the tongue. Specimens were also obtained from the surface of the tongue in the CTL group, whose tongues did not show lesions. Samples were obtained from the surface of the denture foundation in both groups. Fungiflora Y stain was used for the detection of Candida using a fluorescence microscope.
Results: In the EC group, Candida was detected at a high percentage of positivity from both the tongue lesion (20/23 cases, 87.0%) and the dentures (21/23 cases, 91.3%) by culture examination. Similarly, microscopy demonstrated a high positive rate in the dentures (17/23 cases, 73.9%), as well as in the tongue lesion (19/23 example, 82.6%). In the CTL group, Candida was detected with a comparatively high positive rate by culture examination sampling from both the dorsum of the tongue and the dentures, 7/9 cases (77.8%) and 6/9 cases (66.7%), respectively. On the other hand, microscopic examination in the CTL group detected Candida in only 3/9 cases (33.3%) from the dorsum of the tongue, and in no cases from the dentures. Thus, it was found that Candida was detected microscopically with a high rate from the denture foundation in cases of erythematous candidiasis.
Conclusion: The results suggest that dentures on which a Candida bio-film has formed are a potential cause of erythematous candidiasis, and that microscopic examination using Fungiflora Y is useful for evaluating the risk factor.

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This study examined the usefulness of levobupivacaine for inducing conduction anesthesia of the mandibular foramen for pain management after operation. The subjects were 30 patients who underwent extraction of an impacted mandibular wisdom tooth (G. B. Winter's impaction classification: Class II, Position B). All subjects were ASA Class I patients and provided informed consent. Tooth extraction was performed after infiltration anesthesia with 3.0 ml of a 2% lidocaine hydrochloride solution containing 1/80000 adrenalin. Oral surgeons with more than five years of clinical experience performed all procedures and the surgical stress was approximately equal. Patients then received 2 ml of 0.25% levobupivacaine solution (Group I, 10 subjects), 0.25% bupivacaine solution (Group II, 10 subjects), or 2% lidocaine hydrochloride solution containing 1/80,000 adrenalin (Group III, 10 subjects) for conduction anesthesia of the mandibular foramen. Each group was assessed for postoperative pain levels, Visual Analogue Scale (VAS) scores, time of onset of unbearable postoperative pain, time of the first administration of an analgesic drug (60 mg loxoprofen sodium), and frequency of analgesic administration to manage unbearable postoperative pain. Postoperative pain levels were scored by patients immediately after surgery and at 30, 60, 90, 120, 180, 240, 300, and 360 min after surgery using VAS scores ranging from “no pain” (left) to “worst imaginable pain” (right). Sufficient instruction for scoring pain levels was given to patients before surgery. VAS scores were determined by measuring from the left of the line to the vertical bar marked by patients. Significant increases in the VAS scores were observed postoperatively at 120 min and 90 min in Group I and Group III, respectively, but were not observed in Group II within the measuring time. The onset of unbearable pain occurred significantly later in Group I and Group II (191 ± 71 min and 170 ± 89 min after surgery, respectively) than in Group III (88 ± 46 min after surgery). The time of the first analgesic administration was 253 ± 90 min, 196 ± 68 min, and 125 ± 55 min after surgery in Group I, Group II, and Group III, respectively, and the differences between Group I and Group III were significant. Our results showed that the duration of the effect of levobupivacaine is not significantly different from that of bupivacaine. However, taking into account central nervous system toxicity and cardio toxicity, levobupivacaine is an appropriate drug for conduction anesthesia in postoperative pain management of the mandibular foramen.

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We conducted a study assess the bactericidal activity of Sitafloxacin (STFX) against 6 type strain and 1 ATCC strain of main causative organisms of odontogenic infection. Each strain tested was grown in hemosupplemented Brain Heart infusion broth and adjusted to approximately 10⁵ CFU/mL. Test strains were then exposed to 1 × MIC and T-Cmax, antimicrobial tissue level that would be attained with routine antimicrobial administration. Bactericidal activity was measured for up to 8 hours. Against P. intermedia and S. intermedius, bactericidal activity of STFX was shown for up to 8 hours following 1 × MIC.
At T-Cmax, only STFX demonstrated a 3-5 log CFU/mL reduction against P. gingivalis, P. intermedia, S. intermedius and S. gordonii. Furthermore, compared to the other new quinolones tested, only STFX demonstrated rapid and strong bactericidal activity.
Our study shows that when maximum tissue penetration is achieved, with the exception of F. necrophorum, STFX shows strong bactericidal activity against causative organisms of odontogenic infections that it may show the most effective clinical utility including mandibular osteomyelitis and other difficult infections in oral surgery.

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Many dentists have indicated that NSAIDs cannot be used for tooth pain and temporomandibular disorders and that antimicrobial agents are not available for dental infections despite their effectiveness because they are not approved for dental indications. In many cases, dentists hesitate to use drugs for children or pregnant women because their package inserts indicate that “safety has not been established” even when they are not unapproved or are drugs used for unapproved indications. Thus, many problems exist with the pharmacotherapy in dental care provided by health insurance. A Survey of Problems with Pharmacotherapy for Dental Care Provided by Health Insurance: General Survey Focusing on Unapproved Drugs/Drugs Used for Unapproved Indications was therefore performed. The results showed that many dentists have difficulty in providing routine care because effective drugs were not approved for dental indications. Many dentists thought that clinical development should be advanced to approve unapproved drugs and drugs used for unapproved indications, giving examples, such as antimicrobial agents, analgesics, and psychotropic agents. Dentists hoped that investigator-initiated trials would be performed and that the insurance examination process would address the issue to approve more drugs for dental indications. They also hoped that related organizations and Japanese association for dental societies would take a leadership role in achieving these goals.

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