Odontogenic infections in the antibiotic era: approach to diagnosis, management, and prevention.

PURPOSE: The prevalence of odontogenic infections remains one of the highest in the world. If untreated, odontogenic infections can break through the limitation, disseminate to other organs or spaces, and cause high mortality rates. However, it is still difficult to rapidly target limited or disseminated infections in clinical practice. The type of disseminated odontogenic infections and the responsible bacteria have not been described in detail. METHODS: Search databases (e.g., PubMed, MEDLINE, Web of Science, Embase) for reports published from 2018.1 to 2022.9. Use search strategies: ("odontogenic infections" OR "pulpitis" OR "periapical lesions" OR "periodontal diseases") AND ("disseminated infections" OR "complication"). RESULTS: Fourteen different types of disseminated odontogenic infections, most of which are polymicrobial infections, can spread through the body either direct or through hematogenous diffusion. Multiple microbial infections can be more invasive in the transmission of infection. Secondary infections are commonly associated with bacteria like Fusobacterium spp., Streptococcus spp., Peptostreptococcus spp., Prevotella spp., and Staphylococcus spp. Antibiotics with broad-spectrum activity are fundamental as first-line antimicrobial agents based on the microorganisms isolated from disseminated infections. CONCLUSION: This review elaborates on the epidemiology, microorganisms, risk factors, and dissemination routes, and provides evidence-based opinions on the diagnosis, multidisciplinary management, and prevention of odontogenic infections for dentists and clinicians.

Clinical accuracy of partially guided implant placement in edentulous patients: A computed tomography-based retrospective study.

OBJECTIVES: This retrospective study was intended to evaluate the clinical accuracy of partially guided template in guiding implant placement in edentulous patients. METHODS: A total of 120 implants were placed in 24 patients with at least one completely edentulous arch with a partially guided system. Based on CBCT data, a repeatable method was used to measure linear and angular deviations of implants at 3D level in Mimics medical software. The influence of supporting tissue and implant region on the accuracy was assessed, followed by the evaluation of direction of linear deviations in biologically vital areas. RESULTS: Linear deviations of all implants were 1.91 ± 0.68 mm, 1.47 ± 0.68 mm, and 1.02 ± 0.69 mm at apical, apical lateral, and apical vertical levels. When at the cervical, cervical lateral, and cervical vertical levels, the linear deviations were 1.53 ± 0.65 mm, 0.98 ± 0.53 mm, and 1.01 ± 0.69 mm, respectively. Angular deviation of all implants was 7.14 ± 3.41°. Implants guided by mucosa + tooth-supported templates showed higher linear deviations at apical vertical level (1.21 ± 0.72 mm vs. 0.86 ± 0.63 mm, p < .05) and cervical vertical level (1.18 ± 0.72 mm vs. 0.87 ± 0.63 mm, p < .05) than mucosa-supported templates, and implants in maxilla were found higher angular deviation than mandible (7.89 ± 3.61° vs. 6.29 ± 2.97°, p < .05). CONCLUSIONS: The partially guided template served as clinically viable surgical assistance in implant placement in edentulous patients. When using mucosa + tooth-supported template or placing implants in maxilla, more caution was required, especially in biologically vital areas.

Comparative evaluation of transverse width indices for diagnosing maxillary transverse deficiency.

OBJECTIVES: This study aimed to compare and evaluate different transverse width indices for diagnosing maxillary transverse deficiency (MTD), a common malocclusion characterized by uncoordinated dental arches, crossbites, and tooth crowding. MATERIALS AND METHODS: Sixty patients aged 7-12 years were included in the study, with 20 patients diagnosed with MTD and 40 normal controls. Transverse width indices, including maxillary width at the buccal alveolar crest and lingual midroot level, as well as at the jugal process width, were measured. Differences between these indices and their corresponding mandibular indices were used as standardized transverse width indices. The reference range of these indices was determined and evaluated. Receiver operating characteristic (ROC) analysis was performed to evaluate their diagnostic ability. RESULTS: The transverse width indices and standardized transverse width indices of the MTD group were significantly smaller than those of the control group, except for the jugal process width. The evaluation of the reference range and ROC analysis revealed that the difference of the maxillomandibular width at buccal alveolar crest was the most accurate diagnostic method. CONCLUSIONS: The jugal point analysis method may not be suitable for diagnosing MTD. Instead, measuring the difference in maxillomandibular width at the buccal alveolar crest proves to be a more reliable and accurate diagnostic method for MTD.

Anatomy and function of the canalis sinuosus and its injury prevention and treatment strategies in implant surgery. / çª¦ç®¡çš„è§£å‰–ä¸ŽåŠŸèƒ½åŠå ¶åœ¨ç§æ¤æœ¯ä¸­æŸä¼¤çš„é˜²æ²»ç­–ç•¥.

The canalis sinuosus, a canal containing the anterior superior alveolar nerve bundle, originates from the infraorbital canal and extends along the maxillary sinus and nasal cavity edges to the anterior maxilla. It was once regarded as an anatomical variation. However, with the widespread application of cone beam computed tomography (CBCT), the detection rate of canalis sinuosus in the population has increased. The canalis sinuosus exhibits diverse courses, branching into multiple accessory canals and terminating at the nasal floor or the anterior tooth region, with the majority traversing the palatal side of the central incisor. The anterior superior alveolar nerve bundle within the canalis sinuosus not only innervates and nourishes the maxillary anterior teeth, their corresponding soft tissues, and the maxillary sinus mucosa, but also relates to the nasal septum, lateral nasal wall, and parts of the palatal mucosa. To minimize surgical complications, implantologists need to investigate strategies for preventing and treating canalis sinuosus injuries. Preoperatively, implantologists should use CBCT to identify the canalis sinuosus and virtually design implant placement at a distance of more than 2 mm from the canalis sinuosus. Intraoperatively, implantologists should assess bleeding and patient comfort, complemented by precision surgical techniques such as the use of implant surgical guide plates. Postoperatively, CBCT can be employed to examine the relationship between the implant and the canalis sinuosus, and treatment of canalis sinuosus injuries can be tailored based on the patient's symptoms. This review summarizes the detection of canalis sinuosus in the population, its anatomical characteristics, and its physiological functions in the anterior maxilla, and discusses strategies for effectively avoiding canalis sinuosus injuries during implant surgery, thereby enhancing implantologists' awareness and providing references for clinical decision-making.

Research progress in effect of chewing-side preference on temporomandibular joint and its relationship with temporo-mandibular disorders. / åä¾§å’€åš¼å¯¹é¢žä¸‹é¢Œå ³èŠ‚ç»“æž„çš„å½±å“åŠå ¶ä¸Žé¢žä¸‹é¢Œå ³èŠ‚ç´Šä¹±çš„å ³ç³».

Chewing-side preference is one of the risk factors for temporomandibular disorders (TMD), and people with chewing-side preference is more prone to have short and displaced condyles, increased articular eminence inclination and glenoid fossa depth. The proportion of TMD patients with chewing-side preference is often higher than that of the normal subjects. Clinical studies have shown a strong correlation between chewing-side preference and TMD symptoms and signs; and animal studies have shown that chewing-side preference can affect the growth, development, damage and repair of the mandible. After long-term unilateral mastication, changes in the stress within the joint cause the imbalance of temporomandibular joint (TMJ) structural reconstruction, the transformation and even destruction of the fiber structure of masticatory muscle, resulting in uncoordinated movement of bilateral muscles. The joint neurogenic diseases caused by the increase of neuropeptide substance P and calcitonin-gene-related-peptide (CGRP) released locally by TMJ may be the mechanism of TMD. This article reviews the research progress of the influence of chewing-side preference on the structure of TMJ, the relationship between chewing-side preference and TMD, and the related mechanisms.

A Potential Complication After Drainage in Odontogenic Descending Necrotizing Mediastinitis: Chyle Leakage.

ABSTRACT: Descending necrotizing mediastinitis is a serious complication of odontogenic infections. Incision and drainage of the maxillofacial infection with mediastinal drainage represent the principal management. However, chyle leakage after drainage in descending necrotizing mediastinitis is rare and has not been reported. Here the authors present a case of a 74-year-old man with chyle leakage after mediastinal drainage, which is successfully treated.

A Retrospective Study of 158 Cases on the Risk Factors for Recurrence in Ameloblastoma.

Background: Ameloblastoma is an odontogenic tumor occurring in jaws, with local aggressiveness and postoperative recurrence. This study was aim to investigate the clinical and radiographic risk factors for recurrence in ameloblastoma. Methods: Patients diagnosed with ameloblastoma between March 2009 and March 2019 were retrospectively analyzed. Clinical and Radiological data and follow-up records were collected. Survival analyses were performed by Kaplan-Meier and log-rank tests, as well as Cox proportional hazards model. Results: One hundred and fifty-eight patients (104 males and 54 females were enrolled. The overall recurrence rate for ameloblastoma was 13.29%, and 10.76% recurred within 5 years. Most of the tumors were located in mandible (86.71%), while the rest 21 cases were in maxilla (13.29%). More than half cases (55.06%) showed multilocular radiolucency, 61 cases (38.61%) showed unilocular radiolucency. Significant differences were found with amelobastoma recurrence rate related to treatment modality, impacted tooth and root resorption (P =0.002, 0.022 and 0.007 respectively). Conclusions: Treatment modality, impacted tooth and root resorption all showed statistically significant associations with the recurrence rate in ameloblastoma. However, due to the limitation of this study, further studies are needed to reveal the true mechanism of ameloblastoma recurrence.

Early bone formation in mini-lateral window sinus floor elevation with simultaneous implant placement: An in vivo experimental study.

OBJECTIVE: To investigate the early bone formation in beagles with mini-lateral window sinus floor elevation and simultaneous implant placement. MATERIAL AND METHODS: Six beagles were selected for the split-mouth design procedures. In each animal, one maxillary recess received a 5 mm-diameter mini-round lateral osteotomy (test group), and the contralateral maxillary recess received a large rectangular osteotomy (10 mm long and 8 mm wide), (control group). Simultaneous implant installation was executed on bilateral maxillary recesses. Tetracycline and calcein dyes were administered on the 14th, 13th days and the 4th, 3rd days prior to sacrifice, respectively. After 8 weeks of healing, the beagles were euthanized for fluorescent labeling and histomorphometric analyses. RESULTS: In both groups, new bone formation initiated from the circumferential native bone of the maxillary recesses and extended toward the central sub-recess cavities. The maxillary recesses with the mini-window procedures exhibited superior mineral apposition rate, bone formation rate, and the percentage of new bone area to those of the group exposed to large osteotomy procedure (p < .05). While there was no significant difference in the value of bone-to-implant contact, the mini-window group displayed a tendency for an increase in this aspect (p > .05). Bone formation rate and new bone amount were not statistically correlated with bone-to-implant contact (p > .05). CONCLUSION: The hypothesis that mini-lateral window sinus floor elevation with simultaneous implant placement would improve early new bone formation in augmented sinus compared with large lateral window procedure is accepted.

The association between low birth weight and dental caries among 11-to-13-year-old school age children in Ningbo, China.

BACKGROUND: The association between low birth weight (LBW) and dental caries is currently unclear. The aim of this study was to investigate the association of LBW with dental caries in permanent teeth in children of Ningbo city. METHODS: A total of 1975 children aged 11-to-13 years in Ningbo, China were enrolled in this cross-sectional study. LBW was defined as a birthweight< 2500 g. Ten dentists assessed the status of dental caries in permanent teeth in line with the World Health Organization (WHO) criteria and guidelines. Decayed, missing or filled teeth were considered to have dental caries. Parental questionnaires were used to collect child information. Non-conditional logistic regression analysis was used to estimate odds ratios (ORs) and the corresponding 95% confidence intervals (CIs). RESULTS: Dental caries in permanent teeth was found in 610 children (30.9%), with a mean DMFS of 2.09 (SD = 1.2). The adjusted ORs for dental caries in permanent teeth was 1.46 (95% CI 1.00, 2.13) for LBW. CONCLUSIONS: LBW was not associated with dental caries in permanent teeth in the study population.

Skull Base Sphenoid Bone: A Potential Route of Brain Abscesses Induced by Odontogenic Infection.

ABSTRACT: Odontogenic foci are rarely linked with brain abscesses. The lack of an effective approach to match the causative origin with the infection can lead to late medical response of patients. Here we present a case of a 53-year-old man with brain abscesses that was probably caused by odontogenic foci. The imaging examinations clearly showed the periodontitis of mandibular left second molar and the destruction of greater sphenoid wing. Therefore, possible routes of extension through masticator space abscesses were indicated. For early infection of the maxillofacial space caused by potential odontogenic lesions, oral surgeons should eliminate the potentially odontogenic foci and use computerized tomography imaging to determine the existence of bone destruction around the oral cavity such as the skull to prevent further bone defect complications such as brain abscesses.

Effects of precementation on minimizing residual cement around the marginal area of dental implants.

STATEMENT OF PROBLEM: Residual cement is detrimental to the long-term success of dental implants with a cement-retained restoration. The complete elimination of excess cement remains a challenge. PURPOSE: The purpose of this in vitro study was to evaluate the effects of precementation technique on minimizing the residual cement and retention of restorations. MATERIAL AND METHODS: Four custom cobalt-chromium alloy (Co-Cr) abutments were manufactured by computer-aided design and computer-aided manufacturing (CAD-CAM) as precementation abutments with height and radius reductions of 25 µm (A25), 50 µm (A50), 75 µm (A75), and 100 µm (A100). Fifty CAD-CAM-fabricated standard Co-Cr abutments and corresponding crowns were randomly matched and treated as follows: 10 specimens were cemented with the conventional cementation procedure with glass ionomer cement (G0), and 40 were precemented with precementation abutments (n=10) before the definitive cementation with standard abutments (G25, G50, G75, G100). The weight of the cement in the cement space was calculated, and the marginal sealing was evaluated by using a stereoscopic microscope. The effects of precementation with resin cement on minimizing residual cement around the marginal area of dental implants were further evaluated extraorally. The influence of precementation with glass ionomer and resin cement on the retention force was analyzed by using a universal testing machine at a crosshead speed of 0.5 mm/min. One-way ANOVA was used to analyze cement mass and marginal sealing values. Two-way ANOVA was used to compare the retention forces (α=.05). RESULTS: The cement weight of G50 (7.2 ±0.6 mg) was significantly higher than that of G25 (6.0 ±1.1 mg, P<.05), while no significant differences in cement weights were found among G50, G75, and G100. Consistently, the G50, G75, and G100 had higher marginal sealing values than that of the G25 (P<.01). Extraoral experiments showed that the precementation with A50 reduced subgingival residual cement without affecting retention. CONCLUSIONS: These in vitro results suggest that precementation with a precisely manufactured precementation abutment minimized the residual cement around implant abutments, and 50 µm could be a preferable precementation space.

Enhanced osteogenesis of quasi-three-dimensional hierarchical topography.

Natural extracellular matrices (ECMs) are three-dimensional (3D) and multi-scale hierarchical structure. However, coatings used as ECM-mimicking structures for osteogenesis are typically two-dimensional or single-scaled. Here, we design a distinct quasi-three-dimensional hierarchical topography integrated of density-controlled titania nanodots and nanorods. We find cellular pseudopods preferred to anchor deeply across the distinct 3D topography, dependently of the relative density of nanorods, which promote the osteogenic differentiation of osteoblast but not the viability of fibroblast. The in vivo experimental results further indicate that the new bone formation, the relative bone-implant contact as well as the push-put strength, are significantly enhanced on the 3D hierarchical topography. We also show that the exposures of HFN7.1 and mAb1937 critical functional motifs of fibronectin for cellular anchorage are up-regulated on the 3D hierarchical topography, which might synergistically promote the osteogenesis. Our findings suggest the multi-dimensions and multi-scales as vital characteristic of cell-ECM interactions and as an important design parameter for bone implant coatings.

Enhanced cellular osteogenic differentiation on Zn-containing bioglass incorporated TiO2 nanorod films.

Surface nanotopography and bioactive ions have been considered to play critical roles on the interactions of biomaterials with cells. In this study, a TiO2 nanorod film incorporated with Zn-containing bioactive glass (TiO2/Zn-BG) was prepared on tantalum substrate, trying to evaluate the synergistic effects of nanotopograpgy and bioactive ions to promote cellular osteogenic differentiation activity. The expression of osteogenic-related genes, ALP as well as the ECM mineralization on TiO2/Zn-BG film were significantly upregulated compared to that of the film without TiO2 nanorod nanostructure (Zn-BG) or without Zn (TiO2/BG). Moreover, a much low Zn2+ release level on TiO2/Zn-BG film was beneficial to promote the osteogenesis, which could be ascribed to that a semi-closed space established by TiO2 nanorods with adhered cells provided an appropriate micro-environment that facilitated Zn2+ adsorption.

Positive effect of strontium-oxide layer on the osseointegration of moderately rough titanium surface in non-osteoporotic rabbits.

OBJECTIVES: To evaluate the effect of strontium-oxide layer on new bone formation and osseointegration of sandblasted large-grit double-acid-etched (SLA) implant. MATERIAL AND METHODS: Strontium-oxide layer on the SLA surface was produced by hydrothermal treatment using a Sr-containing solution. The surface topographies, roughness, hardness values, chemical elements and ionic release of SLA and the strontium-containing SLA (Sr-SLA) surface were measured by special instruments separately. Sixty-four SLA and Sr-SLA implants were inserted into the proximal tibiae and femoral condyles of sixteen non-osteoporotic New Zealand white rabbits. The biological effects were evaluated by removal torque (RTQ) testing and histomorphometric analysis after 3 and 6 weeks of implantation. RESULTS: The surface characteristics showed Sr-SLA surfaces with dotted nanostructures can release appropriate amount of strontium ions into surrounding tissue till 14 days. In vivo, the Sr-SLA implants presented significantly higher RTQ than SLA implants at 3 and 6 weeks (P < 0.05). The Sr-SLA implants presented higher bone-to-implant contact (BIC) than SLA implants in cortical bone at 3 and 6 weeks (P < 0.05). The bone area was slightly higher for the Sr-SLA implants at 3 and 6 weeks (P > 0.05). CONCLUSIONS: The strontium-oxide layer on the SLA surface has the potential to improve implant osseointegration in non-osteoporotic rabbits.

[Application of modified lateral window for maxillary sinus floor augmentation].

Objective: To evaluate the clinical efficacy of modified lateral window for maxillary sinus floor augmentation (MSFA). Methods: Fifty-five patients who visited the Stomatology Hospital Affiliated to Zhejiang University School of Medicine between June 2012 and October 2014 were enrolled in the study. Patients underwent MSFA with Bio-Oss grafts based on modified access window. During the operation the vertical height of the bony window was reduced from 6-8 mm of conventional oval window to 4-5 mm of slot-shaped window. The sinus membrane was detached completely via the lateral access and large particle Bio-Oss graft was placed in the sub-mucosal space. The implant survival, graft height, graft volume and resorption rates were measured. Intra-op and post-op complications were recorded. Results: There were 86 implants inserted. The 2-4 year cumulative survival rates were 97.67% by implant-based analysis and 96.36% by patient-based analysis. The residual bone height was (4.7±2.6) mm and bone width was (8.4±2.7) mm. The bone height of implantation site immediately after operation was (16.1±2.5) mm and it was (16.2±2.2) mm at restoration. The bone heights at 1 and 2 years after operation were (14.9±2.5) mm and (13.6±2.6) mm, respectively. The graft height was (10.6±2.8) mm and the graft volume was (1569±745) mm3 immediately after operation. The resorption rate of graft height 6 months after operation was 3.79% and that of graft volume was 7.87%. The 1-year accumulative resorption rate of graft height was 6.63% and that of graft volume was 10.89%. The 2-year accumulative resorption rate of graft height was 7.58% and that of graft volume was 15.26%. Small membrane perforation during MSFA was observed in 5 cases and all were successfully repaired by a collagen Bio-Gide membrane. Conclusion: The modified lateral technique obtains high implant survival rate, excellent graft stability and low complication rate at 2-4 year clinical follow-up, indicating that it is a safe, predictable and minimally invasive surgical method for severe atrophic maxillary posterior dentition.

Long-term outcomes of osteotome sinus floor elevation without bone grafts: a clinical retrospective study of 4-9 years.

OBJECTIVE: To evaluate the long-term clinical and radiographic outcomes of dental implant placed using osteotome sinus floor elevation (OSFE) without bone grafts, and to analyze the potential influence factors of implant survival and endo-sinus bone remodeling. MATERIAL AND METHODS: A retrospective study design was adopted. The clinical and radiographic data of 96 implants in 80 patients were collected after 4-9 (mean 5.40) years follow-up. Implant failures, peri-implant marginal bone loss (MBL), and endo-sinus bone remodeling on the radiographs were evaluated. A life-table analysis was used to assess the implant survival. Statistical models were established to investigate the potential influence factors of implant survival and endo-sinus bone gain (ESBG). RESULTS: In total, nine implants in seven patients failed, giving the 9-year cumulative survival rates of 90.6% and 91.3% for implant-based analysis and patient-based analysis, respectively. The mean MBL between implant installation and the 4- and 9-year follow-up visit was 0.46 ± 0.88 and 0.50 ± 1.69 mm, respectively. The average ESBG on radiographs was 2.95 ± 1.25 and 2.16 ± 1.13 mm at the 4- and 9-year follow-up. The final ESBG was found to be positively correlated to implant protrusion length after surgery without any other factors related. The implant survival rate was significantly lower in severe atrophic site (residual bone height <5 mm). CONCLUSION: Osteotome sinus floor elevation without bone grafts is a predictable treatment modality in the long run. But it should be used with caution when the initial bone height of the edentulous site is lower than 5 mm. The final endo-sinus bone height was found to be positively correlated to implant protrusion length measured on radiographs immediately after implant installation.

A three-dimensional quantitative assessment on bony growth and symmetrical recovery of mandible after decompression for unicystic ameloblastoma.

Unicystic ameloblastoma (UAM) of the jaw can be effectively reduced in volume through decompression, which promotes bone regeneration and restores jaw symmetry. This study quantitatively evaluated changes in mandible volume and symmetry following decompression of mandibular UAM. This study included 17 patients who underwent surgical decompression followed by second-stage curettage for mandibular UAM. Preoperative and postoperative three-dimensional computed tomography (CT) images were collected. Bone volume and the area of cortical perforation were measured to assess bone growth during decompression. Mandibular volumetric symmetry was analyzed by calculating the volumetric ratio of the two sides of the mandible. Twelve pairs of landmarks were identified on the surface of the lesion regions, and their coordinates were used to calculate the mean asymmetry index (AI) of the mandible. Paired t-tests and the Mann-Whitney U test were used for statistical analysis, with p < 0.05 considered indicative of statistical significance. The mean duration of decompression was 9.41 ± 3.28 months. The mean bone volume increased by 8.07 ± 2.41%, and cortical perforation recovery was 71.97 ± 14.99%. The volumetric symmetry of the mandible improved significantly (p < 0.05), and a statistically significant decrease in AI was observed (p < 0.05). In conclusion, UAM decompression enhances bone growth and symmetry recovery of the mandible. The present evaluation technique is clinically useful for quantitatively assessing mandibular asymmetry.

Reliabilities of three methods used to evaluate computer-assisted mandibular reconstructions using free fibula flaps.

Objective: This study compared the reliabilities of three different methods used to calculate surgical deviations after mandibular reconstructions using free fibular flaps. Study design: This retrospective study involved 35 patients who underwent computer-assisted mandibular reconstructions using free fibula flaps. The deviations between the virtual surgical plans and the postoperative results were independently analyzed by two researchers using three distinct methods. In Method A, the fibular axis, the center of gravity, and the osteotomy plane served as landmarks when measuring surgical deviations. In Methods B and C, manually designated points were used to measure errors in the fibular length and intersegmental angle. The primary outcome variables were the intraclass correlation coefficients (ICCs) that revealed the inter-rater agreements for all three methods. Results: The use of Method A was associated with good agreement in terms of the fibular length deviation (ICC = 0.765) and intersegmental angle (ICC = 0.897); both were higher than those afforded by Methods B (ICC = 0.158 and 0.108) and C (ICC = 0.406 and 0.463). The measurements of the fibular transfer osteotomy deviation (ICC = 0.888), linear deviation (0.926), and angular deviation (0.958) were very reliable. Conclusions: Method A afforded the highest reliability in clinical practice when evaluating surgical deviations after mandibular reconstruction using fibular flaps.

Mineralized collagen coatings formed by electrochemical deposition.

Understanding and controlling the process of electrochemical deposition (ECD) of a mineralized collagen coating on metallic orthopedic implants is important for engineering highly bioactive coatings. In this work, the influence of different ECD parameters was investigated. The results showed that the mineralization degree of the coatings increased with deposition time, voltage potential and H2O2 addition, while chitosan addition led to weakening of mineralization, heavy mineralization resulted in a porous coating morphology. Furthermore, two typical coatings, dense and porous, were analyzed to investigate their microstructure and evaluated for their cytocompatibility; the dense coating showed better osteoblast adhesion and proliferation. Based on our understanding of how the different coating parameters influenced the coating, we proposed an ECD process in which the pH gradient near the cathode and the collagen isoelectric point were suggested to play crucial roles in controlling the mineralization and morphology of the coatings. The proposed ECD process may offer a guide for controlled deposition of a desired bioactive coating.

Influence of peripheral enamel bonding and chlorhexidine pretreatment on resin bonding to dentin.

PURPOSE: To evaluate the influence of peripheral enamel bonding, chlorhexidine digluconate (CHX) pretreatment, and storage time on resin-dentin microtensile bond strength (µTBS) of a self-etching adhesive system and selfetching cement. MATERIALS AND METHODS: Fifty-six noncarious human third molars were coronally sectioned to provide a flat dentin surface; the circumferential enamel was removed from half of these and the other half was left intact. Pretreatment with 0.2% or 2% CHX or none (control) was performed before bonding composite blocks with Panavia F2.0 or RelyX Unicem to dentin. Specimens were stored in 0.5% chloramine for 3 days (control) or 6 months. Bonded specimens were sectioned into 1-mm2 dentin-only beams and a tensile load was applied until failure. The resulting 14 test groups, defined by control group/storage time/cement/CHX application mode/enamel bonding, were analyzed using two-way and three-way ANOVA, as well as Tukey's HSD post-hoc test (α = 0.05). Failure patterns of the specimens were observed and measured using scanning electron microscopy. RESULTS: The comparison of the control vs experimental subgroups with peripheral enamel bonding and without CHX pretreatment after six months found no significant differences regarding the µTBS between the cements (p > 0.05) but did for the storage time (p <= 0.05). When storing the specimens for six months, the absence of peripheral enamel bonding significantly decreased the µTBS (p <= 0.05). Panavia F2.0 specimens showed significantly higher µTBS values than RelyX Unicem specimens (p <= 0.05). CHX pretreatment, regardless the concentration, showed a significant influence on the µTBS (p <= 0.05). SEM revealed that peripheral enamel bonding reduced failures at the resin/dentin interface. CONCLUSIONS: The absence of peripheral enamel bonding and a longer storage time decrease the µTBS of twostep self-etching adhesive system and a one-step self-etching cement. CHX pretreatment of the dentinal surfaces seems to improve the durability of the bond to dentin.