Effects of quaternary ammonium chain length on the antibacterial and remineralizing effects of a calcium phosphate nanocomposite

Composites containing nanoparticles of amorphous calcium phosphate (NACP) remineralize tooth lesions and inhibit caries. A recent study synthesized quaternary ammonium methacrylates (QAMs) with chain lengths (CLs) of 3–18 and determined their effects on a bonding agent. This study aimed to incorporate these QAMs into NACP nanocomposites for the first time to simultaneously endow the material with antibacterial and remineralizing capabilities and to investigate the effects of the CL on the mechanical and biofilm properties. Five QAMs were synthesized: DMAPM (CL3), DMAHM (CL6), DMADDM (CL12), DMAHDM (CL16), and DMAODM (CL18). Each QAM was incorporated into a composite containing 20% NACP and 50% glass fillers. A dental plaque microcosm biofilm model was used to evaluate the antibacterial activity. The flexural strength and elastic modulus of nanocomposites with QAMs matched those of a commercial control composite (n 5 6; P . 0.1). Increasing the CL from 3 to 16 greatly enhanced the antibacterial activity of the NACP nanocomposite (P , 0.05); further increasing the CL to 18 decreased the antibacterial potency. The NACP nanocomposite with a CL of 16 exhibited biofilm metabolic activity and acid production that were 10-fold lesser than those of the control composite. The NACP nanocomposite with a CL of 16 produced 2-log decreases in the colony-forming units (CFU) of total microorganisms, total streptococci, and mutans streptococci. In conclusion, QAMs with CLs of 3–18 were synthesized and incorporated into an NACP nanocomposite for the first time to simultaneously endow the material with antibacterial and remineralization capabilities. Increasing the CL reduced the metabolic activity and acid production of biofilms and caused a 2-log decrease in CFU without compromising the mechanical properties. Nanocomposites exhibiting strong anti-biofilm activity, remineralization effects, and mechanical properties are promising materials for tooth restorations that inhibit caries.     

A novel protein-repellent dental composite containing 2-methacryloyloxyethyl phosphorylcholine

Secondary caries due to biofilm acids is a primary cause of dental composite restoration failure.To date,there have been no reports of dental composites that can repel protein adsorption and inhibit bacteria attachment.The objectives of this study were to develop a protein-repellent dental composite by incorporating 2-methacryloyloxyethyl phosphorylcholine(MPC) and to investigate for the first time the effects of MPC mass fraction on protein adsorption,bacteria attachment,biofilm growth,and mechanical properties.Composites were synthesized with 0(control),0.75%,1.5%,2.25%,3%,4.5%and 6%of MPC by mass.A commercial composite was also tested as a control.Mechanical properties were measured in three-point flexure.Protein adsorption onto the composite was determined by the microbicinchoninic acid method.A human saliva microcosm biofilm model was used.Early attachment at 4 h,biofilm at 2 days,live/dead staining and colony-forming units(CFUs) of biofilms grown on the composites were investigated.Composites with MPC of up to 3%had mechanical properties similar to those without MPC and those of the commercial control,whereas 4.5%and 6%MPC decreased the mechanical properties(P<0.05).Increasing MPC from 0 to 3%reduced the protein adsorption on composites(P<0.05).The composite with 3%MPC had protein adsorption that was 1/12 that of the control(P<0.05).Oral bacteria early attachment and biofilm growth were also greatly reduced on the composite with 3%MPC,compared to the control(P<0.05).In conclusion,incorporation of MPC into composites at 3%greatly reduced protein adsorption,bacteria attachment and biofilm CFUs,without compromising mechanical properties.Protein-repellent composites could help to repel bacteria attachment and plaque build-up to reduce secondary caries.The protein-repellent method might be applicable to other dental materials.     

Novel rechargeable calcium phosphate nanoparticle-containing orthodontic cement

White spot lesions (WSLs), due to enamel demineralization, occur frequently in orthodontic treatment. We recently developed a novel rechargeable dental composite containing nanoparticles of amorphous calcium phosphate (NACP) with long-term calcium (Ca) and phosphate (P) ion release and caries-inhibiting capability. The objectives of this study were to develop the first NACP-rechargeable orthodontic cement and investigate the effects of recharge duration and frequency on the efficacy oftion re-release. The rechargeable cement consisted of pyromellitic glycerol dimethacrylate (PMGDM) and ethoxylated bisphenol A dimethacrylate (EBPADMA). NACP was mixed into the resin at 40% by mass. Specimens were tested for orthodontic bracket shear bond strength (SBS) to enamel, Ca and P ion initial release, recharge and re-release. The new orthodontic cement exhibited an SBS similar to commercial orthodontic cement without CaP release (P>0.1). Specimens after one recharge treatment (e.g., 1 min immersion in recharge solution repeating three times in one day, referred to as"1 min 3 times") exhibited a substantial and continuous re-release of Ca and P ions for 14 days without further recharge. The ion re-release did not decrease with increasing the number of recharge/re-release cycles (P>0.1). The ion re-release concentrations at 14 days versus various recharge treatments were as follows:1 min 3 times>3 min 2 times>1 min 2 times>6 min 1 time>3 min 1 time>1 min 1 time. In conclusion, although previous studies have shown that NACP nanocomposite remineralized tooth lesions and inhibited caries, the present study developed the first orthodontic cement with Ca and P ion recharge and long-term release capability. This NACP-rechargeable orthodontic cement is a promising therapy to inhibit enamel demineralization and WSLs around orthodontic brackets.     

Primer containing dimethylaminododecyl methacrylate kills bacteria impregnated in human dentin blocks

Antibacterial dimethylaminododecyl methacrylate (DMADDM) was recently synthesized. The objectives of this study were to:(1) investigate antibacterial activity of DMADDM-containing primer on Streptococcus mutans impregnated into dentin blocks for the first time, and (2) compare the antibacterial efficacy of DMADDM with a previous quaternary ammonium dimethacrylate (QADM). Scotchbond Multi-Purpose (SBMP) bonding agent was used. DMADDM and QADM were mixed into SBMP primer. Six primers were tested:SBMP control primer P, P+2.5%DMADDM, P+5%DMADDM, P+7.5%DMADDM, P+10%DMADDM, and P+10%QADM. S. mutans were impregnated into human dentin blocks, and each primer was applied to dentin to test its ability to kill bacteria in dentinal tubules. Bacteria in dentin were collected via a sonication method, and the colony-forming units (CFU) and inhibition zones were measured. The bacterial inhibition zone of P+10%DMADDM was 10 times that of control primer (Po0.05). CFU in dentin with P+10%DMADDM was reduced by three orders of magnitude, compared with control. DMADDM had a much stronger antibacterial effect than QADM, and antibacterial efficacy increased with increasing DMADDM concentration. Dentin shear bond strengths were similar among all groups (P40.1). In conclusion, antibacterial DMADDM-containing primer was validated to kill bacteria inside dentin blocks, possessing a much stronger antibacterial potency than the previous QADM. DMADDM-containing bonding agent was effective in eradicating bacteria in dentin, and its efficacy was directly proportional to DMADDM mass fraction. Therefore, DMADDM may be promising for use in bonding agents as well as in other restorative and preventive materials to inhibit bacteria.     

Role of saliva proteinase 3 in dental caries

Salivary analysis can be used to assess the severity of caries. Of the known salivary proteins, a paucity of information exists concerning the role of proteinase 3 (PR3), a serine protease of the chymotrypsin family, in dental caries. Whole, unstimulated saliva was collected from children with varying degrees of active caries and tested using a Human Protease Array Kit and an enzyme-linked immunosorbent assay. A significantly decreased concentration of salivary PR3 was noted with increasing severity of dental caries (P<0.01); a positive correlation (r=0.87; P<0.01; Pearson''s correlation analysis) was also observed between salivary pH and PR3 concentration. In an antibacterial test, a PR3 concentration of 250 ng·mL⁻¹ or higher significantly inhibited Streptococcus mutans UA159 growth after 12 h of incubation (P<0.05). These studies indicate that PR3 is a salivary factor associated with the severity of dental caries, as suggested by the negative relationship between salivary PR3 concentration and the severity of caries as well as the susceptibility of S. mutans to PR3.     

Evaluation of three-dimensional biofilms on antibacterial bonding agents containing novel quaternary ammonium methacrylates

Antibacterial adhesives are promising to inhibit biofilms and secondary caries. The objectives of this study were to synthesize and incorporate quaternary ammonium methacrylates into adhesives, and investigate the alkyl chain length effects on three-dimensional biofilms adherent on adhesives for the first time. Six quaternary ammonium methacrylates with chain lengths of 3, 6, 9, 12, 16 and 18 were synthesized and incorporated into Scotchbond Multi-Purpose. Streptococcus mutans bacteria were cultured on resin to form biofilms. Confocal laser scanning microscopy was used to measure biofilm thickness, live/dead volumes and live-bacteria percentage vs. distance from resin surface. Biofilm thickness was the greatest for Scotchbond control; it decreased with increasing chain length, reaching a minimum at chain length 16. Live-biofilm volume had a similar trend. Dead-biofilm volume increased with increasing chain length. The adhesive with chain length 9 had 37% live bacteria near resin surface, but close to 100% live bacteria in the biofilm top section. For chain length 16, there were nearly 0% live bacteria throughout the three-dimensional biofilm. In conclusion, strong antibacterial activity was achieved by adding quaternary ammonium into adhesive, with biofilm thickness and live-biofilm volume decreasing as chain length was increased from 3 to 16. Antibacterial adhesives typically only inhibited bacteria close to its surface; however, adhesive with chain length 16 had mostly dead bacteria in the entire three-dimensional biofilm. Antibacterial adhesive with chain length 16 is promising to inhibit biofilms at the margins and combat secondary caries.     

Progress toward understanding the contribution of alkali generation in dental biofilms to inhibition of dental caries

Alkali production by oral bacteria is believed to have a major impact on oral microbial ecology and to be inibitory to the initiation and progression of dental caries.A substantial body of evidence is beginning to accumulate that indicates the modulation of the alkalinogenic potential of dental biofilms may be a promising strategy for caries control.This brief review highlights recent progress toward understanding molecular genetic and physiologic aspects of important alkali-generating pathways in oral bacteria,and the role of alkali production in the ecology of dental biofilms in health and disease.     

Role of sortase in Streptococcus mutans under the effect }f nicotine

Streptococcus mutans is a common Gram-positive bacterium and plays a significant role in dental caries. Tobacco and/or nicotine have documented effects on S. mutans growth and colonization. Sortase A is used by many Gram-positive bacteria, including S. mutans, to facilitate the insertion of certain cell surface proteins, containing an LPXTGX motif such as antigen 1/11. This study examined the effect of nicotine on the function of sortase A to control the physiology and growth of S. mutans using wild-type S. mutans NG8, and its isogenic sortase-defective and -complemented strains. Briefly, the strains were treated with increasing amounts of nicotine in planktonic growth, biofilm metabolism, and sucrose-induced and saliva-induced antigen I/ll-dependent biofilm formation assays. The strains exhibited no significant differences with different concentrations of nicotine in planktonic growth assays. However, they had significantly increased （P~〈 0.05） biofilm metabolic activity （2- to 3-fold increase） as the concentration of nicotine increased. Furthermore, the sortase-defective strain was more sensitive metabolically to nicotine than the wild-type or sortase-complemented strains. All strains had significantly increased sucrose-induced biofilm formation （2- to 3-fold increase） as a result of increasing concentrations of nicotine. However, the sortase-defective strain was not able to make as much sucrose- and saliva-induced biofilm as the wild-type NG8 did with increasing nicotine concentrations. These results indicated that nicotine increased metabolic activity and sucrose-induced biofilm formation. The saliva-induced biofilm formation assay and qPCR data suggested that antigen 1/11 was upregulated with nicotine but biofilm was not able to be formed as much as wild-type NG8 without functional sortase A.     

Alanine racemase is essential for the growth and interspecies competitiveness of Streptococcus mutans

D-alanine (D-Ala) is an essential amino acid that has a key role in bacterial cell wall synthesis. Alanine racemase (Alr) is a unique enzyme that interconverts L-alanine and D-alanine in most bacteria, making this enzyme a potential target for antimicrobial drug development. Streptococcus mutans is a major causative factor of dental caries. The factors involved in the survival, virulence and interspecies interactions of S. mutans could be exploited as potential targets for caries control. The current study aimed to investigate the physiological role of Alr in S. mutans. We constructed alr mutant strain of S. mutans and evaluated its phenotypic traits and interspecies competitiveness compared with the wild-type strain. We found that alr deletion was lethal to S. mutans. A minimal supplement of D-Ala (150μg·mL?1) was required for the optimal growth of the alr mutant. The depletion of D-alanine in the growth medium resulted in cell wall perforation and cell lysis in the alr mutant strain. We also determined the compromised competitiveness of the alr mutant strain relative to the wild-type S. mutans against other oral streptococci (S. sanguinis or S. gordonii), demonstrated using either conditioned medium assays or dual-species fluorescent in situ hybridization analysis. Given the importance and necessity of alr to the growth and competitiveness of S. mutans, Alr may represent a promising target to modulate the cariogenicity of oral biofilms and to benefit the management of dental caries.     

Congenital agenesis of all major salivary glands and absence of unilateral lacrimal puncta: a case report and review of the literature

Abstract Congenital agenesis of the salivary glands is an extremely rare congenital condition, which may cause severe xerostomia, progressive dental caries, and oropharyngeal candidiasis in children. To date, there have been few documented cases of aplasia of the major salivary glands. Congenital agenesis of the salivary glands accompanied by absence of the lacrimal puncta is even more rare. We report a case of a 5-year-old boy with xerostomia and extensive dental caries. Salivary gland imaging with sodium pertechnetate 99mTcO(4) showed bilateral aplasia of the parotid, submandibular, and sublingual glands. The patient was found to lack the left lacrimal puncta through physical examination. Here we describe the clinical presentation, diagnostic essentials, and medical and dental management of the patient.     

Saliva in the diagnosis of diseases

Saliva is secreted from the salivary glands and has multiple functions, including mouth cleaning and protection, antibacterial effects and digestion. With the rapid advancement in salivaomics, saliva is well recognized as a pool of biological markers. Saliva, as a non-invasive and safe source, could be a substitute for blood in the diagnosis and prognosis of diseases. This review summarizes the latest advancements in saliva-related studies and addresses the potential value of saliva in the early diagnosis of oral diseases, such as dental caries and periodontal disease, as well as cancer, diabetes and other systemic disorders. Saliva biomarkers range from changes in the biochemical indices of DNA, RNA and proteins to the diversification of microbiota structures. This study integrates data reported in the recent literature and discusses the clinical significance and prospects for the application of saliva in the early diagnosis of diseases, translational medicine and precision medicine.     

Modeling of diffusion transport through oral biofilms with the inverse problem method

Aim The purpose of this study was to develop a mathe-matical model to quantitatively describe the passive trans-port of macromoleeules within dental biofilms. Methodology Fluorescently labeled dextrans with different molecular mass (3 kD, 10 kD, 40 kD, 70 kD, 2 000 kD) were used as a series of diffusion probes. Streptococcus mutans, Streptococcus sanguinis, Actinomyces naeslundii and Fusobacterium nucleatum were used as inocula for biofilm formation. The diffusion processes of different probes through the in vitro biofilm were recorded with a confocal laser microscope.Results Mathematical function of biofilm penetration was constructed on the basis of the inverse problem method. Based on this function, not only the relationship between average concentration of steady-state and molecule weights can be analyzed, but also that between penetrative time and molecule weights. Conclusion This can be used to predict the effective concentration and the penetrative time of anti-biofilm medicines that can diffuse through oral biofilm. Further-more, an improved model for large molecule is proposed by considering the exchange time at the upper boundary of the dental biofilm.     

Otopathogenic Pseudomonas aeruginosa strains as competent biofilm formers

OBJECTIVE: To determine whether Pseudomonas aeruginosa, a common cholesteatoma pathogen, known to form biofilms in other chronic infections, is capable of contributing to biofilm formation in cholesteatoma. DESIGN: We tested 12 OPPA isolates for several aspects of biofilm formation, including adherence to human keratinocytes, expression of quorum-sensing genes, twitching motility, and production of extracellular matrix as determined by both crystal violet staining and carbazole reaction. RESULTS: Ten OPPA strains demonstrated increased adherence (1.5- to 12-fold) to human keratinocytes relative to PAO1, a laboratory strain. Expression of las and rhl quorum-sensing products were detected in 11 OPPA strains. By crystal violet staining, we found biofilm formation in all OPPA strains equal to or greater than that found in PAO1 (2- to 18-fold). In addition, OPPA strains demonstrated mucoid characteristics, including down-regulation of twitching motility and increased alginate production. CONCLUSIONS: Strains of OPPA isolated from cholesteatoma are strongly adherent to keratinocytes and capable of forming biofilm. In addition, OPPA strains have mucoid characteristics in vitro. When these bacteria assume a biofilm phenotype, they are highly resistant to antibiotics and host defenses. These data suggest that OPPA can contribute to biofilm formation in cholesteatoma, leading to the persistence of this infection.     

Oral health status in Sichuan Province:findings from the oral health survey of Sichuan, 2015–2016

To investigate oral health status in the residents of Sichuan Province, southwest China, a cross-sectional study was performed using the latest Oral Health Survey Basic Methods recommended by the World Health Organization. A multistage stratified random cluster-sampling method was used to enroll participants from the following three groups: children aged 3–5 years, adolescents aged 12 years, and people aged 65–74 years. In these three groups, the mean numbers of teeth that were affected by caries were 3.28, 0.86 and 5.13, respectively, resulting in a prevalence of 63.47%, 37.20%and 83.20%, respectively. Relative to the high rate of decayed teeth, the prevalence of fillings was very low in all age groups (0.97%, 7.24% and 5.43%, respectively). In the 12-year-old adolescent group, only 3.61%had good pit and fissure sealing. In addition, the rate of dental fluorosis was 24.80%, and the Community Fluorosis Index value was 0.39. In the elder group, the community periodontal index was 2.92. The prevalence in the elderly of having lost at least one tooth was 75.54%. Additionally, 4.44%of these participants were edentulous. The incidence of dental prosthesis was 51.75%, the proportion with a removable partial denture, a fixed denture, full dentures, dental implants and an informal fixed bridge was 21.59%, 11.45%, 4.64%, 0 and 16.67%, respectively. In this study, 8.2%of the elderly participants were affected by different types of oral mucosal lesions. Among such lesions, recurrent aphthous ulcers were most prevalent (2.69%) and oral lichen planuses were second (1.6%). The conclusion presented in this survey is that oral diseases, especially dental caries and periodontal disease, are frequent and common in Sichuan province, China. Moreover, the treatment rate is very low, and primary prevention and treatment options are therefore urgently needed in this population.     

Nonlinear finite element analysis of three implant-abutment interface designs

The objective of this study was to investigate the mechanical characteristics of implant-abutment interface design in a dental implant system,using nonlinear finite element analysis (FEA) method. This finite element simulation study was applied on three commonly used commercial dental implant systems:model I,the reduced-diameter 3i implant system (West Palm Beach,FL,USA) with a hex and a 12-point double internal hexagonal connection; model II,the Semados implant system (Bego,Bremen,Germany) with combination of a conical (45° taper) and internal hexagonal connection; and model III,the Brnemark implant system (Nobel Biocare,Gothenburg,Sweden) with external hexagonal connection. In simulation,a force of 170 N with 45° oblique to the longitudinal axis of the implant was loaded to the top surface of the abutment. It has been found from the strength and stiffness analysis that the 3i implant system has the lowest maximum von Mises stress,principal stress and displacement while the Brnemark implant system has the highest. It was concluded from our preliminary study using nonlinear FEA that the reduced-diameter 3i implant system with a hex and a 12-point double internal hexagonal connection had a better stress distribution,and produced a smaller displacement than the other two implant systems.     

Dental caries and first permanent molar pit and fissure morphology in 7- to 8-year-old children in Wuhan, China

To obtain the caries experience and,plaque accumulation severity and pit and fissure morphology in first permanent molars in 7-8 children in Wuhan,as a reasonable prediction of caries risk and preventive attention in the future,a convenient sample of five primary schools in the vicinity of the Wuhan University School and Hospital of Stomatology was drawn.Two calibrated examiners orally examined all present grade 2 children in the classroom,using standard caries plaque and tooth morphology criteria.Dental caries was scored at enamel(D 2) and dentine(D 3) for tooth and surface level.Independent variables were age,gender and school.Data analysis used analysis of variance and t-test.The sample comprised 1 043 7-and 8-year-olds.The prevalence of dental caries in permanent dentition was 8.7% and in primary dentition,68.7%.Mean Decayed,Missing,Filled Teeth/S(DMFT/S) scores were 0.11 and 0.14,respectively.Mean dmft/s scores were 2.8 and 5.0.The d-component constituted 75% of the d 3 mft index,while enamel carious lesions constituted 36% of the total number of carious lesions(d 2,3-component).Prevalence of medium and deep pits and fissures was 84.6%.Prevalence of medium and severe plaque accumulation was 67.4%.Prevalence of dental caries in the deciduous and permanent dentitions of 7-to 8-year-old children was high.Deep pits and fissures in high caries risk children should be sealed.     

In vitro Antimicrobial Activity of SinuSurf™

Background: Topical surfactant therapy has been found to be effective in the management of recalcitrant chronic rhinosinusitis. Objective: To determine in vitro the antibacterial potential of SinuSurf?, a previously commercially available sinonasal surfactant. Methods: Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (PA) cultures were grown in the presence or absence of serial dilutions of mupirocin or gentamicin with and without SinuSurf and quantified by colony-forming units (CFUs). Biofilm formation was also assessed. Finally, bacterial growth was evaluated in sinus irrigation bottles inoculated with MRSA or PA and rinsed daily with SinuSurf. Results: SinuSurf alone evinced a 3-log (1,000-fold) and 6-log (10(6)-fold) reduction in CFUs for MRSA and PA, respectively. The combination of SinuSurf with a 1:10 dilution mupirocin and 1:100 dilution gentamicin demonstrated complete bacterial eradication. Similar concentrations of antibiotic dilutions alone demonstrated bacterial growth. SinuSurf averaged an 83% MRSA and 76% PA reduction in biofilm formation. Bottle contamination evaluation demonstrated reduction of MRSA and PA (p < 0.05) with SinuSurf. Conclusion: Biofilms have been demonstrated in chronic rhinosinusitis patients and implicated in recalcitrant disease. Our in vitro data demonstrates the addition of SinuSurf improved the effectiveness of a lower concentration of topical antibiotics in biofilm mass and viability.     

In silico identification of potential inhibitors targeting Streptococcus mutans sortase A

Dental caries is one of the most common chronic diseases and is caused by acid fermentation of bacteria adhered to the teeth. Streptococcus mutans (S. mutans) utilizes sortase A (SrtA) to anchor surface proteins to the cell wall and forms a biofilm to facilitate its adhesion to the tooth surface. Some plant natural products, especially several flavonoids, are effective inhibitors of SrtA. However, given the limited number of inhibitors and the development of drug resistance, the discovery of new inhibitors is urgent. Here, the high-throughput virtual screening approach was performed to identify new potential inhibitors of S. mutans SrtA. Two libraries were used for screening, and nine compounds that had the lowest scores were chosen for further molecular dynamics simulation, binding free energy analysis and absorption, distribution, metabolism, excretion and toxicity (ADMET) properties analysis. The results revealed that several similar compounds composed of benzofuran, thiadiazole and pyrrole, which exhibited good affinities and appropriate pharmacokinetic parameters, were potential inhibitors to impede the catalysis of SrtA. In addition, the carbonyl of these compounds can have a key role in the inhibition mechanism. These findings can provide a new strategy for microbial infection disease therapy.     

A prospective randomized study of a dental appliance compared with uvulopalatopharyngoplasty in the treatment of obstructive sleep apnoea.

The enthusiasm for uvulopalatopharyngoplasty (UPPP) in the treatment of obstructive sleep apnoea (OSA) has declined in recent years, partly because of a lower success rate over time and partly because of adverse effects. Reports on the beneficial effects of dental appliances exist, but only one prospective randomized study has been published comparing dental appliances with nasal continuous positive airway pressure (CPAP) treatment. No study has been published comparing dental appliance treatment with UPPP. Ninety-five male patients with confirmed OSA, subjective daytime sleepiness and an apnoea index (AI) > 5 were randomized for subsequent treatment with either a dental appliance or UPPP. There were 49 patients in the dental appliance group and 46 in the UPPP group. Thirty-seven patients in the dental appliance group and 43 in the UPPP group completed the 12-month follow-up. The success rate (rate of patients with at least a 50% reduction in AI) for the dental appliance group was 95%, which was significantly higher (p < 0.01) than the 70% success rate for the UPPP group. According to the criteria for OSA (apnoea index > or = 5 or apnoea/hypopnoea index > or = 10), 78% of the dental appliance group and 51% of the UPPP group were normalized after 12 months. The difference between the groups was significant (p < 0.05). These findings suggest that the dental appliance technique is useful in the treatment of mild to moderate OSA.     

Systematic qualitative histology of enossal implants with anodically oxidised surfaces]

Histological analysis of dental implants is often quantified by calculating the bone-implant contact rate (bone volume/total volume), whereas qualitative aspects like osteoconduction are underrepresented. The aim of this study was to focus on the micro-architectural properties of the bone-implant contact under physiologic loading using a systematic analysis of these characteristics.In 16 Beagle dogs we inserted 6 different types of dental implants in the hard bone of the mandible and the soft bone of the maxilla. After a healing period of two months the implants were loaded for three months and then histologically analysed. For the metric evaluation of qualitative histological aspects 12 examiners answered pivotal questions: 1. Is the implant functional sufficient? 2. Do you see close contact to bone, were bone is present? 3. Is the amount of bone at the implant at least similar to the peripheral bone? 4. Is the bone to implant contact homogenous? 5. Does the bone show a functional architecture? 6. Do you find osseoconductive bone apposition at the crestal and apical border? A superiority of anodic oxidized surfaces can be seen in questions 1, 2 and 3 mainly for the comparison of identical macrodesigns (MkIII). The potential for osseoconductivity (questions 4 and 5) shows a tendency for significant differences for the ZL Ticer implant. Homogenous bone to implant contact is rarely found, in contrast to rather positive implant function ratings. This suggests the existence of an optimum in the bone to implant contact rate.Bone to implant contact rate as an isolated quantitative parameter should in future be completed by a systematic, standardised and blinded analysis of qualitative properties.