Initial subgingival colonization of 'pristine' pockets

The treatment of periodontitis/peri-implantitis involves the reduction/eradication of periopathogens. After therapy, beneficial and pathogenic species recolonize the subgingival area. The dynamics of recolonization and especially the role of the supragingival environment in this process are still not well-understood. This prospective, split-mouth study followed the early colonization of 'pristine' pockets created during implant surgery (16 partially edentulous patients), to record the time needed before a complex subgingival flora could be established with the supragingival area as the single source. Four subgingival plaque samples were taken from shallow and medium pockets around implants (test), and neighboring teeth (undisturbed microbiota as reference) 1, 2, and 4 wks after abutment connection. Checkerboard DNA-DNA hybridization and culture data revealed a complex microbiota (including several pathogenic species) in the pristine pockets within a wk, with a minimal increase in counts up to 4 wks. Analysis of these data demonstrated that, even with the supragingival environment as the single source for colonizing bacteria, a complex subgingival microbiota can develop within 1 wk.     

Smoking, a weak predictor of periodontitis in older adults

BACKGROUND: The impact of smoking habits on periodontal conditions in older subjects is poorly studied. AIMS: To assess if a history of smoking is associated with chronic periodontitis and medical history in older subjects. MATERIAL AND METHODS: The medical and dental history was collected from 1084 subjects 60-75 years of age. Smoking history information was obtained from self-reports. Periodontal variables [clinical probing depth (PD)>/=5.0 mm, clinical attachment levels (CALs) >/=4.0 mm], and radiographic evidence of alveolar bone loss were assessed. RESULTS: 60.5% had never smoked (NS), 32.0% were former smokers (FS) (mean smoke years: 26.1 years, SD+/-13.1), and 7.5% were current smokers (CS) (mean smoke years 38.0 years, (SD+/-12.1). The proportional distribution of CAL >/=4.0 mm differed significantly by smoking status (NS and CS groups) (mean difference: 12.1%, 95% confidence interval (CI): 1.5-22.6, p<0.02). The Mantel-Haenszel common odds ratio between smoking status (CS+FS) and periodontitis (>20% bone loss) was 1.3 (p<0.09, 95% CI: 0.9-2.0) and changed to 1.8 (p<0.02, 95% CI: 1.3-2.7) with 30 years of smoking as cutoff. A weak correlation between number of years of smoking and CAL>/=4.0 mm was demonstrated (r(2) values 0.05 and 0.07) for FS and CS, respectively. Binary logistic forward (Wald) regression analysis demonstrated that the evidence of carotid calcification, current smoking status, gender (male), and the number of remaining teeth were explanatory to alveolar bone loss. CONCLUSIONS: A clinically significant impact on periodontal conditions may require 30 years of smoking or more. Tooth loss, radiographic evidence of carotid calcification, current smoking status, and male gender can predictably be associated with alveolar bone loss in older subjects.     

Multi-unit fixed partial denture for a bilateral cleft palate patient: a clinical report

Patients with cleft palates eventually require definitive fixed or removable dental prostheses after the maintenance of arch alignment and occlusal relationship during adolescence. This case report presents application of a resin composite veneered fixed partial denture utilized as a definitive prosthesis for a bilateral cleft palate patient after stable occlusion had been established orthodontically. The composite veneered long span fixed partial denture provides adequate aesthetics and function.     

EDTA treatment improves resin-dentin bonds' resistance to degradation

The existence of unprotected collagen fibrils within the hybrid layer compromises the longevity of restorations. This phenomenon may be avoided if solutions other than strong acids are used for dentin demineralization. The hypothesis to be tested is that bond durability may be improved by EDTA demineralization. Dentin surfaces (human and bovine) were bonded: (1) after phosphoric-acid-etching, and after EDTA demineralization with (2) a total-etch adhesive and (3) a self-etching adhesive. After the teeth were sectioned into beams, half of the specimens were immersed in NaOCl, while the other half was immersed in water. Beams were tested to failure in tension. ANOVA and multiple-comparisons tests were used (P < 0.05). No differences in bond strength were found among the 3 bonding procedures, although bonds made to human molars were 43-61% higher than those to bovine incisors. After NaOCl immersion, only specimens subjected to EDTA demineralization maintained the initial bond strength. We conclude that the collagen network is better-preserved after EDTA demineralization.     

Apoptosis and cell cycle arrest in oral lichen planus Hypothesis on their possible influence on its malignant transformation

The quantitative importance of cell cycle arrest and apoptosis mechanisms in oral lichen planus (OLP) was analysed in order to assess the cell response to T lymphocyte aggression and establish a hypothesis on the influence of these phenomena in the malignant transformation process. The TUNEL assay and immunohistochemical methods were used to detect caspase-3, bax, and p21 in 32 tissue samples of oral mucosa with OLP and in 20 samples of normal oral mucosa. Positivity for TUNEL, caspase-3 and p21 was significantly more frequent in cases than in controls (p<0.001). Both TUNEL and caspase-3 positivity was significantly greater in the basal versus suprabasal layer (p=0.004 and 0.052, respectively). The basal and suprabasal expression of p21 was significantly higher in cases with a more intense liquefaction degeneration (p<0.01). There was no significant difference in basal expression of bax between cases and controls. The quantitative importance of apoptosis was small in OLP. Epithelial cells attacked in OLP have a very low response to apoptosis and cell cycle arrest mechanisms, which may produce an epithelial substrate that favours malignant transformation.     

Insoluble zinc, cupric and tin pyrophosphates inhibit the formation of volatile sulphur compounds

Oral malodour is mainly a result of the production of volatile sulphur compounds (VSC). The present study was concerned with investigating the anti-VSC effect of insoluble pyrophosphates (PP) of zinc, copper(II) and tin(II). The hypothesis to be tested was that the sulphide anions produced when VSC are solubilized in water have a higher affinity for the respective metal ions than the PP anion. The anti-VSC effects of insoluble PP were compared with the corresponding soluble metal salts using three in vitro methods: saliva putrefaction; dialysis of a suspension of PP and saliva against water; and analysis of water containing hydrogen sulphide and methyl mercaptan gases, and gases in the headspace. The levels of VSC were analysed by gas chromatography in the first and third methods, and released metal ions were analysed by atomic absorption spectroscopy in the second. The results showed that: the insoluble metal PP inhibited VSC formation in saliva by 99-100%; under dialysis, only minute amounts of metal ions are released from the combination of PP and saliva; and the PP lost their metal cations in water containing dissolved gases and inhibited VSC formation. Hence, the results support the experimental hypothesis. Sulphide ions are obviously very strong ligands for these metal ions.     

Molecular evaluation of residual endodontic microorganisms after instrumentation, irrigation and medication with either calcium hydroxide or Septomixine

BACKGROUND AND OBJECTIVE: The correct choice of antimicrobial agents as inter-appointment medicaments is as important as the instrumentation and irrigation to remove pathogens from infected root canals. Calcium hydroxide [Ca(OH)2] and framycetin sulfate (Septomixine) are common endodontic medicaments. Therefore, we evaluated the efficacy of either calcium hydroxide or Septomixine in eliminating residual intra-canal bacteria, particularly Actinomyces spp., during inter-appointment interval in endodontic therapy using molecular methods. METHODS: A total of 31 single-rooted teeth with primary root canal infections were studied immediately after opening the canals and subsequently after instrumentation, irrigation with sterile saline and 1-week medication with either Ca(OH)2 (n = 25) or Septomixine (n = 6). Whole bacterial genomic DNA was isolated directly from samples and PCR with universal primers performed to detect total intra-canal bacteria. The variable regions of 16S rDNA of bacteria were amplified and labeled with digoxigenin for further hybridization to detect Actinomyces spp. A total of seven oligonucleotide probes specific for A. bovis, A. gerencseriae, A. israelii, A. meyeri, catalase-negative A. naeslundii (genospecies 1 and 2), catalase-positive A. naeslundii genospecies 2 and A. odontolyticus were used to detect Actinomyces spp. in 22 of 31 medicated root canals [Ca(OH)2: n = 17; Septomixine: n = 5]. RESULTS: The PCR results showed that 25 of 31 examined canals were positively detected with residual microorganisms after instrumentation, irrigation with sterile saline and 1-week medication with either Ca(OH)2 (n = 20) or Septomixine (n = 5). Thus, only six canals [Ca(OH)2: n = 5, Septomixine: n = 1] were aseptic after treatment. Hybridization results showed higher detection frequency of both A. odontolyticus and A. gerencseriae after treatment. Significant correlation was found between exposed pulp before treatment and positive detection of Actinomyces spp., particularly A. odontolyticus on the second visit (P < 0.05). CONCLUSION: The conventional, 1-week medication of either Ca(OH)2 or Septomixine in endodontic therapy may not effectively inhibit residual bacterial growth in all root canals during inter-appointment intervals. Further investigations using, for instance quantitative real-time PCR analyses, are required to substantiate the present findings.     

Pain and anxiety reduction using a manual stimulation distraction device when administering local analgesia oro-dental injections: a multi-center clinical investigation

OBJECTIVE: This study was designed to assess the effects of a manual stimulating distraction device (Isoflex referred to as Manual Stimulation Distraction Device or MSDD) for reducing pain and anxiety experienced with standard dental local anesthetic injections. Additionally, the memory recall effects on injection pain and anxiety were also explored. METHODOLOGY: Patients from different dental clinics were identified by their practitioners as requiring dental procedures under local anesthesia, in the same area on both sides of the mouth. A local anesthetic solution was injected on either the left or right side at different times by random selection; one side using MSDD, while the opposite side used a solution without MSDD. Each patient acted as his or her own symmetrical split-mouth control. The same dentist administered both injections, using identical technique and equipment for each side. Forty-six patients used the MSDD first with the injection, while 54 used MSDD second when they received the injection. Using 10-point visual analogue nominal and ordinal scales, pain and stress were recorded by the patient each time after receiving the injection. The results were pooled and subjected to statistical analysis. Student's paired t-test was employed to test for significant differences in pain and anxiety (stress) when injections were administered with and without MSDD. RESULTS: Results showed significant reductions in perceived pain and stress from local analgesia injections (p < 0.001) when MSDD was used. There was no correlation of pain reduction with age, gender, upper or lower jaw, with or without MSDD. There was a trend for pain and stress to be scored higher for those subjects who had a lower period since the first injection (POFI) scores. This was attributed to recent memory of pain, as POFI scores over one week were significantly lower (p < 0.05). Stress reduction for POFI scores greater than one week proved to be non-significant (p = 0.099). CONCLUSION: In this study, MSDD was effective at reducing pain and stress experienced with local regional analgesic injections.     

Oral-facial-digital syndrome type I. A case report

Oral-facial-digital syndrome type I (OFDI) is a congenital X-linked dominant disorder characterized by anomalies of the oral cavity, face and digits sometimes associated to cerebral malformations and polycystic kidney disease. The gene, responsible for this syndrome, is ofd1. Clinically it is seen only in females. Lesions of the mouth include median pseudoclefting of the upper lip, clefts of the palate and tongue, and dental anomalies (missing or supernumerary teeth, enamel hypoplasia, and teeth malpositions). Dysmorphic features affecting the head include hypertelorism, frontal bossing, micrognathia, facial asymmetry and broadened nasal ridge. The digital abnormalities are syndactyly, clinodactyly, brachydactyly and, rarely, pre or post-axial polydactyly. Less frequently ex-pressed phenotypic anomalies include skin milia, alopecia, deafness and trembling. Sometimes the diagnosis of OFDI can be difficult because there is an overlap with other types of oral-facial-digital syndromes. A sporadic case of OFDI, with 7 lower incisors, both in the primary and permanent dentition, is reported. This dental anomaly is very unusual because in literature only supernumerary cuspids are reported. In the light of this case, the authors discuss the oral phenotypic expression of ofd1 gene and its role in human odontogenesis.