Biomolecular analyses enable new insights into ancient Egyptian embalming.

The ability of the ancient Egyptians to preserve the human body through embalming has not only fascinated people since antiquity, but also has always raised the question of how this outstanding chemical and ritual process was practically achieved. Here we integrate archaeological, philological and organic residue analyses, shedding new light on the practice and economy of embalming in ancient Egypt. We analysed the organic contents of 31 ceramic vessels recovered from a 26th Dynasty embalming workshop at Saqqara1,2. These vessels were labelled according to their content and/or use, enabling us to correlate organic substances with their Egyptian names and specific embalming practices. We identified specific mixtures of fragrant or antiseptic oils, tars and resins that were used to embalm the head and treat the wrappings using gas chromatography-mass spectrometry analyses. Our study of the Saqqara workshop extends interpretations from a micro-level analysis highlighting the socio-economic status of a tomb owner3-7 to macro-level interpretations of the society. The identification of non-local organic substances enables the reconstruction of trade networks that provided ancient Egyptian embalmers with the substances required for mummification. This extensive demand for foreign products promoted trade both within the Mediterranean8-10 (for example, Pistacia and conifer by-products) and with tropical forest regions (for example, dammar and elemi). Additionally, we show that at Saqqara, antiu and sefet-well known from ancient texts and usually translated as 'myrrh' or 'incense'11-13 and 'a sacred oil'13,14-refer to a coniferous oils-or-tars-based mixture and an unguent with plant additives, respectively.

Dairying, diseases and the evolution of lactase persistence in Europe.

In European and many African, Middle Eastern and southern Asian populations, lactase persistence (LP) is the most strongly selected monogenic trait to have evolved over the past 10,000 years1. Although the selection of LP and the consumption of prehistoric milk must be linked, considerable uncertainty remains concerning their spatiotemporal configuration and specific interactions2,3. Here we provide detailed distributions of milk exploitation across Europe over the past 9,000 years using around 7,000 pottery fat residues from more than 550 archaeological sites. European milk use was widespread from the Neolithic period onwards but varied spatially and temporally in intensity. Notably, LP selection varying with levels of prehistoric milk exploitation is no better at explaining LP allele frequency trajectories than uniform selection since the Neolithic period. In the UK Biobank4,5 cohort of 500,000 contemporary Europeans, LP genotype was only weakly associated with milk consumption and did not show consistent associations with improved fitness or health indicators. This suggests that other reasons for the beneficial effects of LP should be considered for its rapid frequency increase. We propose that lactase non-persistent individuals consumed milk when it became available but, under conditions of famine and/or increased pathogen exposure, this was disadvantageous, driving LP selection in prehistoric Europe. Comparison of model likelihoods indicates that population fluctuations, settlement density and wild animal exploitation-proxies for these drivers-provide better explanations of LP selection than the extent of milk exploitation. These findings offer new perspectives on prehistoric milk exploitation and LP evolution.

A genetic history of the pre-contact Caribbean.

Humans settled the Caribbean about 6,000 years ago, and ceramic use and intensified agriculture mark a shift from the Archaic to the Ceramic Age at around 2,500 years ago1-3. Here we report genome-wide data from 174 ancient individuals from The Bahamas, Haiti and the Dominican Republic (collectively, Hispaniola), Puerto Rico, Curaçao and Venezuela, which we co-analysed with 89 previously published ancient individuals. Stone-tool-using Caribbean people, who first entered the Caribbean during the Archaic Age, derive from a deeply divergent population that is closest to Central and northern South American individuals; contrary to previous work4, we find no support for ancestry contributed by a population related to North American individuals. Archaic-related lineages were >98% replaced by a genetically homogeneous ceramic-using population related to speakers of languages in the Arawak family from northeast South America; these people moved through the Lesser Antilles and into the Greater Antilles at least 1,700 years ago, introducing ancestry that is still present. Ancient Caribbean people avoided close kin unions despite limited mate pools that reflect small effective population sizes, which we estimate to be a minimum of 500-1,500 and a maximum of 1,530-8,150 individuals on the combined islands of Puerto Rico and Hispaniola in the dozens of generations before the individuals who we analysed lived. Census sizes are unlikely to be more than tenfold larger than effective population sizes, so previous pan-Caribbean estimates of hundreds of thousands of people are too large5,6. Confirming a small and interconnected Ceramic Age population7, we detect 19 pairs of cross-island cousins, close relatives buried around 75 km apart in Hispaniola and low genetic differentiation across islands. Genetic continuity across transitions in pottery styles reveals that cultural changes during the Ceramic Age were not driven by migration of genetically differentiated groups from the mainland, but instead reflected interactions within an interconnected Caribbean world1,8.

Accurate compound-specific 14C dating of archaeological pottery vessels.

Pottery is one of the most commonly recovered artefacts from archaeological sites. Despite more than a century of relative dating based on typology and seriation1, accurate dating of pottery using the radiocarbon dating method has proven extremely challenging owing to the limited survival of organic temper and unreliability of visible residues2-4. Here we report a method to directly date archaeological pottery based on accelerator mass spectrometry analysis of 14C in absorbed food residues using palmitic (C16:0) and stearic (C18:0) fatty acids purified by preparative gas chromatography5-8. We present accurate compound-specific radiocarbon determinations of lipids extracted from pottery vessels, which were rigorously evaluated by comparison with dendrochronological dates9,10 and inclusion in site and regional chronologies that contained previously determined radiocarbon dates on other materials11-15. Notably, the compound-specific dates from each of the C16:0 and C18:0 fatty acids in pottery vessels provide an internal quality control of the results6 and are entirely compatible with dates for other commonly dated materials. Accurate radiocarbon dating of pottery vessels can reveal: (1) the period of use of pottery; (2) the antiquity of organic residues, including when specific foodstuffs were exploited; (3) the chronology of sites in the absence of traditionally datable materials; and (4) direct verification of pottery typochronologies. Here we used the method to date the exploitation of dairy and carcass products in Neolithic vessels from Britain, Anatolia, central and western Europe, and Saharan Africa.

Milk of ruminants in ceramic baby bottles from prehistoric child graves.

The study of childhood diet, including breastfeeding and weaning, has important implications for our understanding of infant mortality and fertility in past societies1. Stable isotope analyses of nitrogen from bone collagen and dentine samples of infants have provided information on the timing of weaning2; however, little is known about which foods were consumed by infants in prehistory. The earliest known clay vessels that were possibly used for feeding infants appear in Neolithic Europe, and become more common throughout the Bronze and Iron Ages. However, these vessels-which include a spout through which liquid could be poured-have also been suggested to be feeding vessels for the sick or infirm3,4. Here we report evidence for the foods that were contained in such vessels, based on analyses of the lipid 'fingerprints' and the compound-specific δ13C and Δ13C values of the major fatty acids of residues from three small, spouted vessels that were found in Bronze and Iron Age graves of infants in Bavaria. The results suggest that the vessels were used to feed infants with milk products derived from ruminants. This evidence of the foodstuffs that were used to either feed or wean prehistoric infants confirms the importance of milk from domesticated animals for these early communities, and provides information on the infant-feeding behaviours that were practised by prehistoric human groups.

A model approach to show that monocytes can enter microporous ß-TCP ceramics.

ß-TCP ceramics are versatile bone substitute materials and show many interactions with cells of the monocyte-macrophage-lineage. The possibility of monocytes entering microporous ß-TCP ceramics has however not yet been researched. In this study, we used a model approach to investigate whether monocytes might enter ß-TCP, providing a possible explanation for the origin of CD68-positive osteoclast-like giant cells found in earlier works.We used flow chambers to unidirectionally load BC, PRP, or PPP into slice models of either 2 mm or 6 mm ß-TCP. Immunofluorescence for CD68 and live/dead staining was performed after the loading process.Our results show that monocytes were present in a relevant number of PRP and BC slices representing the inside of our 2 mm slice model and also present on the actual inside of our 6 mm model. For PPP, monocytes were not found beyond the surface in either model.Our results indicate the possibility of a new and so far neglected constituent in ß-TCP degradation, perhaps causing the process of ceramic degradation also starting from inside the ceramics as opposed to the current understanding. We also demonstrated flow chambers as a possible new in vitro model for interactions between blood and ß-TCP.

Dual release of daptomycin and BMP-2 from a composite of ß-TCP ceramic and ADA gelatin.

BACKGROUND: Antibiotic-containing carrier systems are one option that offers the advantage of releasing active ingredients over a longer period of time. In vitro sustained drug release from a carrier system consisting of microporous ß-TCP ceramic and alginate has been reported in previous works. Alginate dialdehyde (ADA) gelatin gel showed both better mechanical properties when loaded into a ß-TCP ceramic and higher biodegradability than pure alginate. METHODS: Dual release of daptomycin and BMP-2 was measured on days 1, 2, 3, 6, 9, 14, 21, and 28 by HPLC and ELISA. After release, the microbial efficacy of the daptomycin was verified and the biocompatibility of the composite was tested in cell culture. RESULTS: Daptomycin and the model compound FITC protein A (n = 30) were released from the composite over 28 days. A Daptomycin release above the minimum inhibitory concentration (MIC) by day 9 and a burst release of 71.7 ± 5.9% were observed in the loaded ceramics. Low concentrations of BMP-2 were released from the loaded ceramics over 28 days.

Bioactive apatite-wollastonite glass ceramics coating on metallic titanium for biomedical applications: effect of boron.

Metallic titanium (Ti) implant surfaces need improvement for bioproperties and antibacterial behavior. For this purpose, a new boron-doped bioactive apatite-wollastonite (AW) coating was successfully developed on the Ti plate surface. The effects of boron addition on the microstructure, mechanical properties, and bioproperties of the AW coating were investigated. With the addition of boron (B), the AW coating morphology became less porous and compact. In terms of bio properties, the rate of apatite formation increased with the addition of B, and the cell viability rate increased from approximately 66-81%. B addition increased the elastic modulus of the AW coating from about 24-46 GPa and increased its hardness about 2.5 times. In addition, while no antibacterial activity was observed in the AW coating, the addition of boron slightly introduced antibacterial properties. The novel AW/B composite coating obtained is promising for Ti implant surfaces.

Toward High-Performance Piezoresistive Polymer Derived SiOC Ceramics through Masked Stereolithography 3D Printing with ß-Silicon Carbide Nanopowder Reinforcement.

Enhancing the piezoresistivity of polymer-derived silicon oxycarbide ceramics (SiOCPDC ) is of great interest in the advancement of highly sensitive pressure/load sensor technology for use in harsh and extreme working conditions. However, a facile, low cost, and scalable approach to fabricate highly piezoresistive SiOCPDC below 1400 °C still remains a great challenge. Here, the fabrication and enhancement of piezoresistive properties of SiOCPDC reinforced with ß-SiC nanopowders (SiCNP ) through masked stereolithography-based 3D-printing and subsequent pyrolysis at 1100 °C are demonstrated. The presence of free carbon in SiCNP augments high piezoresistivity in the fabricated SiCNP -SiOCPDC composites even at lower pyrolysis temperatures. A gauge factor (GF) in the range of 4385-5630 and 6129-8987 with 0.25 and 0.50 wt% of SiCNP , respectively is demonstrated, for an applied pressure range of 0.5-5 MPa at ambient working conditions. The reported GF is significantly higher compared to those of any existing SiOCPDC materials. This rapid and facile fabrication route with significantly enhanced piezoresistive properties makes the 3D-printed SiCNP -SiOCPDC composite a promising high-performance material for the detection of pressure/load in demanding applications. Also, the overall robustness in mechanical properties and load-bearing capability ensures its long-term stability and makes it suitable for challenging and severe environment applications.

Antiferroelectric AgNbO3 @KH550 Doped PVDF/PMMA Composites with High Energy Storage Performance.

The residual polarization of antiferroelectric ceramics is very small, yet they possess high energy storage density and efficiency. Incorporating antiferroelectric ceramic particles into a polymer matrix is beneficial for improving the energy storage performance of composites. However, excessive amounts of ceramic particles can lead to aggregation within the polymer, resulting in defects and a significant reduction in composite film performance. In this study, the antiferroelectric AgNbO3 is selected as the filler and modified with silane coupling agent KH550. poly(vinylidene fluoride) (PVDF) and polymethyl methacrylate (PMMA) are blended as the matrix, and the energy storage performance of the composite is improved by adjusting the additional amount of PVDF. The structure, dielectric properties, and energy storage properties of the composites are systematically studied. The results show that hydrogen bonds are formed between PVDF and PMMA, and PVDF and PMMA are tightly bonded under the action of hydrogen bonds. The compatibility of PVDF with PMMA is optimal when the mass fraction of PVDF is 30 wt%. Moreover, with the synergistic effect of the antiferroelectric filler AgNbO3 , the breakdown strength of AgNbO3 /PVDF/PMMA composites reaches 430 kV mm-1 , and the energy storage density reaches 14.35 J cm-3 .

Influence of sterilization on the retention forces of lithium disilicate and polymer-infiltrated ceramic-network crowns bonded to titanium base abutments: An in-vitro study.

OBJECTIVES: The aim of this study was to evaluate the effect of sterilization on the retention forces of lithium disilicate (LD) and polymer-infiltrated ceramic network (PICN) crowns bonded to titanium base (Ti-base) abutments. MATERIALS AND METHODS: Forty LD and 40 PICN crowns were milled and then bonded to 80 Ti-bases with two resin composite cements: Multilink Hybrid Abutment (mh) and Panavia V5 (pv) for a total of 8 groups (n = 10). Half of the specimens (test) underwent an autoclaving protocol (pressure 1.1 bar, 121°C, 20.5 min) and the other half not (control). Restorations were screw-retained to implants, and retention forces (N) were measured with a pull-off testing machine. The surfaces of the Ti-bases and the crowns were inspected for the analysis of the integrity of the marginal bonding interface and failure mode. Student's t-test, chi-square test, and univariate linear regression model were performed to analyze the data (α = 0.05). RESULTS: The mean pull-off retention forces ranged from 487.7 ± 73.4 N to 742.2 ± 150.3 N. Sterilized groups showed statistically significant overall higher maximum retention forces (p < .05), except for one combination (LD + mh). Sterilization led to an increased presence of marginal gaps and deformities compared to no-sterilization (p < .001), while no statistically significant relationship was found between failure mode and sterilization (p > .05). CONCLUSIONS: Sterilization may have a beneficial effect on the retention forces of LD and PICN crowns bonded to titanium base abutments, although it may negatively influence the integrity of the marginal bonding interface.

Microstructure, physical and mechanical properties of dental polychromic multilayer zirconia of uniform composition.

The present study aimed to compare the microstructure, physical, and mechanical properties of three commercially available dental polychromatic multilayer zirconia materials of uniform composition: Dima Mill Zirconia ML, VITA YZ/ST Multicolor, and VITA YZ/XT Multicolor (with 3, 4, and 5 mol% Y2 O3 , respectively); thus, the influence of Y2 O3 content on the above properties of the produced materials was experimentally studied. Homogeneous zirconia ceramics with a dense micro- and nanostructure, without pores or defects, were produced after milling the blocks and sintering, which resulted in yttrium-stabilized tetragonal and cubic zirconia. Statistical analysis of the results of measurable magnitudes was performed by the one-way ANOVA test. The increase of Y2 O3 content (from 3 to 5 mol%) favored larger grain and crystallite sizes and a decrease of the values of the mechanical properties; yet, the differences were statistically insignificant. Clinically, these differences are expected to have no impact on their function in the oral cavity, both in terms of their fracture propensity and the damage that can be caused to the opposing teeth. Accordingly, the experimental results qualify the polychromic multilayer zirconia ceramics of uniform composition fabricated by milling technology for use in dental restorations.

Effects of erosion and abrasion on resin-matrix ceramic CAD/CAM materials: An in vitro investigation.

The aim of the study was to evaluate the effects of erosion and abrasion on resin-matrix ceramic CAD/CAM materials [CERASMART (GC); VITA ENAMIC (VITA Zahnfabrik); Lava Ultimate (3 M)] in comparison to feldspar ceramic (VITABLOCS Mark II, VITA Zahnfabrik) and resin composite materials (ceram.x universal, Dentsply Sirona). Daily brushing and acid exposure were simulated using a brushing apparatus and a solution of 0.5 vol% citric acid. Microhardness, surface roughness, and substance loss were measured at baseline and after simulation of 1 and 3 years of function. All materials showed a decrease in microhardness after 3 years and an increase in surface roughness (Ra) after 1 and 3 years. The Ra increase was statistically significantly lower for the resin-matrix ceramics than for feldspar ceramic and similar to composite material. After 3 years, only feldspar ceramic showed no significant substance loss. In conclusion, resin-matrix ceramics demonstrate reduced roughening compared to feldspar ceramics, potentially improving restoration longevity by preventing plaque buildup, but differences in abrasion resistance suggest the need for further material-specific research. Future research should aim to replicate clinical conditions closely and to transition to in vivo trials.

Finishing technique effect on strength of zirconia-reinforced lithium silicate ceramic.

The aim of this study was to evaluate the effect of two finishing techniques, glazing or polishing, in comparison with the as-cut condition, on the biaxial-flexural-strength (BFS) of a zirconia-reinforced lithium silicate ceramic (ZLS). Cylinders were milled from CAD/CAM blocks and sliced to obtain disc-shaped specimens (ISO6872:2015). Polished and glazed specimens were processed following the manufacturer's instructions. Thirty-three specimens were obtained for each condition and microstructural and BFS/fractographic characterizations were performed. BFS and roughness data were analyzed using Weibull statistics and ANOVA one-way with Tukey post-hoc test, respectively. While a rougher surface was observed for as-cut specimens, smoother surfaces were observed for polished and glazed ZLS at microscopical evaluation and confirmed through surface-roughness evaluation. X-ray spectra depicted a glass phase for all groups and characteristic metasilicate, lithium disilicate, and lithium phosphate peaks for the as-cut and polished specimens. Glazed specimens showed higher characteristic strength than polished and as-cut specimens, which did not differ significantly. While higher Weibull-modulus was observed for the polished than for the as-cut specimens, no statistically significant differences were noted between glazed and polished, and between glazed and as-cut specimens. ZLS presents higher strength when glazed, and polishing increases the structural reliability of the material relative to the as-cut condition. Both finishing techniques reduced surface roughness similarly.

Evaluation of bond strength between zirconia milled ceramic material and veneered dental porcelain.

This study aimed at examining the bond strength between zirconia and ceramic veneer, following the ISO 9693 guidelines. A total of fifty specimens of zirconia/ceramic-veneer system were produced using two commercial zirconias (VITA YZ-HTWhite and Zolid HT+ White, referred to as Group A and Group B, respectively) and a ceramic-veneering material (Zirkonia 750). The microstructure (via x-ray diffraction analysis, XRD and Secondary Electron mode, SEM) and the mechanical properties (via 3-point bending tests) of the two groups were assessed. Then, experiments were conducted according to the ISO 9693 and conventional protocols applied for producing zirconia/ceramic-veneer restorations. Bond strength values, measured by 3-point bending tests, were 34.42 ± 7.60 MPa for Group A and 31.92 ± 6.95 MPa for Group B. SEM observations of the cohesively fractured surfaces (on the porcelain side) and the examination for normality using the Shapiro-Wilk test suggested the use of Weibull statistical analysis. Median strength (σ50%) for Group A and Group B was 34.76 and 32.22 MPa, while the characteristic strength (σ63.2%) was 35.78 and 33.14 MPa, respectively. The Weibull modulus disparity between groups (12.69 and 13.07) was not significant. Bond strength exceeded the ISO 9693 minimum of 20 MPa, suggesting satisfactory strength for clinical use.

Influence of different immediate dentin sealing strategies on bond strength of indirect resin nanoceramic restorations.

In this study, we evaluated the effect of four different strategies for bonding a CAD/CAM resin nanoceramic restoration (Lava Ultimate, 3M) to the dentin surface using a universal adhesive (Scotch Bond Universal, 3M) and adhesive resin cement (RelyX Ultimate, 3M) on the shear bond strength (SBS) and failure mode. The strategies comprised: (i) immediate sealing, immediate bonding; (ii) immediate sealing, bonding after 2 weeks with provisional restoration; (iii) immediate sealing with flowable resin composite reinforcement and bonding after 2 weeks with provisional restoration; and (iv) no immediate sealing, and bonding after 2 weeks with provisional restoration. After bonding, all the specimens were thermocycled, shear tests were performed using a universal testing machine, and failure modes were determined using stereomicroscope and scanning electron microscopy. The highest mean SBS was recorded with immediate sealing, immediate bonding strategy. Most adhesive failures with exposed dentinal tubules were noted in specimens exposed to bonding after 2 weeks with no immediate sealing, which was associated with the lowest SBS. Mixed failures predominated in all immediate dentin sealing groups. Immediate sealing with universal adhesives improves SBS, particularly in the single-visit approach, which has shown significantly better performance, whereas the provisional phase has a negative effect.

Factors Influencing Dentists' Choice of Restorative Materials for Single-Tooth Crowns: A Survey Among Saudi Practitioners.

BACKGROUND Material selection is crucial in restorative dentistry, influenced by aesthetics, material properties, and tooth location. This understanding is key for advancing dental practices and patient outcomes. The present study aimed to assess dentists' preferences for restorative materials in single-tooth crowns (SC) and how abutment tooth location and preparation margins influence these choices. MATERIAL AND METHODS A web-based pre-validated questionnaire survey was conducted among 811 actively practicing dentists in Saudi Arabia. RESULTS In posterior teeth, we found that ceramic was the most preferred material for SC regardless of the abutment tooth location and location of margins, followed by porcelain fused to metal (PFMs). In anterior teeth, ceramics were preferred, followed by CAD/CAM-based resin SC. Among the choice of ceramics in teeth for both supra-gingival margins, monolith zirconia was the most-preferred material for SC fabrication in posterior teeth, followed by zirconia-reinforced lithium silicate ceramic. Similarly, for sub-gingival margins, monolith zirconia crowns were the most popular option in posterior teeth among the respondents, with the highest in the mandibular molar region. In the anterior region, layered zirconia was the least preferred, and lithium disilicate ceramics was the most-favored option. A statistically significant difference existed between supra- and subgingival preparation for teeth 11 (P=0.01), 16 (P=0.03), and 34 (P=0.02). CONCLUSIONS Ceramic was the material of choice among Saudi dentists for replacement of SC, irrespective of the location and preparation margin. Monolith zirconia was usually selected for posterior teeth and lithium disilicate ceramics was the top choice in anterior teeth.

Influence of Chairside Simulated Adjustment (Finishing and Polishing) Protocol and Chlorhexidine Mouthwash Immersion on Color Stability and Translucency of 2 and 3 Preshaded Multilayered Monolithic Zirconia.

BACKGROUND Preshaded monolithic zirconia (MLZ) is reported to have high translucency. This study aimed to assess the effect of chlorhexidine gluconate (ChG) mouthwash on color and translucency parameter (TP) of 2 different preshaded MLZ dental ceramics after clinical adjustment. MATERIAL AND METHODS Two MLZ disk-shaped specimens [NPM (Nacera Pearl Multi-Shade) (n=72) and CZM (Ceramill Zolid FX Multilayer)] (n=72) were simulated for clinical adjustment, finished, and polished using 2 adjustment kits [recommended kit, third-party kit: Diasynt Plus and SUN (n=12 each)] and later immersed in ChG mouthwash (Avohex) for 2 weeks. Difference in color (ΔE) and TP (Y) were calculated using the CIELab formula after measuring the coordinates (Lab) with a colorimeter. Individual changes in color and TP were assessed on the Clinical acceptance (perceptible) threshold (CAT/CPT) and Translucency perception threshold (TPT), respectively. Differences between the 2 ceramics were assessed using one-way ANOVA and post hoc tests, with all differences considered significant at P<0.05. RESULTS NPM and CZM differed in color at baseline despite having the same Vita shade combination. Between the 2 preshaded MLZ ceramics, NPM showed significant changes in color when adjusted with a third-party kit. Chlorhexidine produced changes in color and TP that were designated as clinically perceptible (ΔE=1.0 to 3.3) on the CAT/CPT and TPT scales, irrespective of the adjustment kit used. ChG produced the least or no changes in glazed MLZ specimens. CONCLUSIONS ChG mouthwash, whenever prescribed for preshaded MLZ restoration, should be adjusted prior to final glazing to avoid clinical adjustments that adversely affects color and translucency of the restoration.

Drug eluting bioactive glass ceramics for fusion in spondylodiscitis: a pilot study.

Retrospective observational study. To determine the efficacy and safety of bioactive glass ceramics mixed with autograft in the treatment of spondylodiscitis. Thirty-four patients with spondylodiscitis underwent surgery using autologous bone graft augmented by antibiotic loaded bioactive glass ceramic granules. Twenty-five patients aging 6 to 77, completed 1-year follow-up. The lumbosacral junction was affected in 3, lumbar spine in 13, one each in the dorso-lumbar junction and sacrum, and 7 dorsal spines. The organism isolated was Mycobacterium tuberculosis in 15, Methicillin sensitive Staphylococcus aureus (MSSA) in 4, Pseudomonas aeruginosa in 4, Klebsiella pneumoniae in one, Burkholderia pseudomallei in 1, and mixed infections in 2. All patients had appropriate antibiotic therapy based on culture and sensitivity. Clinical and radiological evaluation of all the patients was done at 6 weeks, 3 months, 6 months, and 12 months after the surgery. Twenty-three patients improved clinically and showed radiographic fusion between 6 and 9 months. The patient with Burkholderia infection died due to fulminant septicemia with multi organ failure while another patient died at 9 months due to an unrelated cardiac event. The mean Visual Analogue Score (VAS) at the end of 1-year was 2 with radiological evidence of fusion in all patients. There were no re-infections or discharging wounds, and the 30-day re-admission rate was 0. Bioactive glass ceramics is a safe and effective graft expander in cases of spondylodiscitis. The absorption of antibiotics into the ceramic appears to help the elimination of infection.

Influence of the orthodontic bonding procedure on biofilm formation.

INTRODUCTION: In orthodontics, white spot lesions are a persistent and widespread problem caused by the demineralization of buccal tooth surfaces around bonded brackets. The remaining adhesive around the brackets leads to surface roughness, which might contribute to demineralization. The present in vitro study aimed to compare a conventional and a modern adhesive system (APC Flash-Free technology) for orthodontic brackets with regard to the adhesion of Streptococcus sobrinus, a leading caries pathogen. METHODS: This in vitro study included 20 premolar teeth and compared 10 APC Flash-Free adhesive-coated ceramic brackets (FF)with 10 conventionally bonded (CB) ceramic clarity brackets. Specimens were incubated in an S. sobrinus suspension for 3 h. To evaluate the bacterial formation, samples were analysed with a scanning electron microscope (SEM). Imaging software was used to quantify and statistically compare percentage values of colonization (PVC) in both groups' adhesion and transition areas. RESULTS: We found a significant difference in biofilm formation between the groups for the adhesive and transition areas. PVC in the adhesive area was approximately 10.3-fold greater for the CB group compared with the FF group (median: 3.2 vs 0.31; P < 0.0001). For the transition area, median PVC was approximately 2.4-fold greater for the CB group compared with the FF group (median: 53.17 vs 22.11; P < 0.01). CONCLUSIONS: There was a significantly lower level of S. sobrinus formation around the FF bracket system than there was surrounding the conventionally bonded group. This study suggests that the FF adhesive bracket system can help reduce the occurrence of bacterial growth around orthodontic brackets.