Adipose Tissue Dysfunction: Impact on Bone and Osseointegration.

Bone metabolism may be adversely affected in metabolic diseases such as obesity and metabolic syndrome, which are characterised by weight gain, due to the expansion of adipose tissue deposits. As an important regulator of energy metabolism, adipose tissues synthesise and secrete several key regulatory adipokines that influence a range of metabolic functions. This narrative review outlines the evidence for the mechanisms by which adipose tissue dysfunction may alter bone metabolism prior to the development of frank hyperglycaemia and presents the emerging evidence for the impact of diet-induced expansion of adipose tissue on implant osseointegration. Successful osseointegration requires normal bone cell function, and the expansion of adipose tissue deposits results in dysregulated adipokine production favouring an increase in pro-inflammatory adipokines, contributing to the development of a chronic inflammatory state and insulin resistance. The increase in inflammatory cytokines promotes the growth and differentiation of osteoclasts indirectly through the modulation of osteoblastic RANKL production and directly by reducing osteoclast apoptosis and increased osteoclastic expression of RANK. Conversely, the suppression of osteoblastic regulatory genes results in reduced osteoblast numbers and function contributing to compromised bone turnover. Compromised osseointegration has been established in hyperglycaemia; however, as discussed in this review, it may not be the only driver of altered bone metabolism. The incidence of metabolic disease in the community is rising, patients may present for implant treatment with undiagnosed, underlying changes to bone cell metabolism due to adipose tissue dysmetabolism.

Functional properties of single motor units in the human medial pterygoid muscle: Thresholds.

BACKGROUND: Little is known regarding the functional properties of single motor units (SMUs) in the medial pterygoid muscle (MPt) during jaw movements. OBJECTIVES: The aims are (a) to report the thresholds of onset of MPt SMUs during 4 goal-directed jaw movement tasks, and (b) to determine whether the threshold of onset of SMU activation varies with the velocity of jaw movement and the location within the muscle. METHODS: Intra-muscular electrodes were inserted in the right MPt of 18 participants performing ipsilateral (right), contralateral, protrusive and opening-closing jaw movements recorded at 2 velocities. Task phases were as follows: BEFORE, OUT, HOLDING, RETURN and AFTER. SMU onset thresholds were determined from the displacement (mm) of the lower mid-incisor point. Electrode location within 4 arbitrary muscle divisions was determined with computer tomography. Statistical tests: Spearman's correlations, Kruskal-Wallis tests; significance accepted at P < .05. RESULTS: A significant inverse relation occurred between velocity and threshold for the RETURN of the ipsilateral movement (n = 62 SMU thresholds), while a significant positive relation occurred for the OUT of the contralateral movement (n = 208); there were no significant associations for the protrusive (n = 131) and opening-closing (n = 58) tasks. Significant threshold differences occurred across the 4 muscle divisions only during the OUT of the contralateral and protrusive movements. Some evidence was provided for gender differences in MPt SMU properties. CONCLUSIONS: The absence of a significant inverse relation between velocity and SMU threshold for most recorded movements suggests the MPt acts as a stabilizer of the jaw in horizontal and opening-closing jaw movements.

The role of progressive oral implant rehabilitation in mastication, cognition and oral health-related quality of life outcomes-A pilot to define the protocol.

BACKGROUND: The implications of oral rehabilitation after tooth loss require further investigation. OBJECTIVES: To conduct a pilot study to investigate: (a) changes in masticatory performance with progressive oral implant rehabilitation (POR); (b) association between POR and neurocognitive function using functional magnetic resonance imaging (fMRI); and (c) oral health-related quality of life (OHQoL) outcomes. METHODS: Four completely edentulous patients (mean age: 73 ± 1.4 years) participated. Each received new complete removable dental prostheses (RDPs) transitioned to mandibular two implant-retained RDPs (IR-RDP). Assessments were performed at 4 time points for neurocognitive skills, fMRI with functional tasks (jaw clenching, working memory and sustained attention, inhibition), masticatory performance with colour-changing gum and OHQoL. Assessments were performed with new complete RDPs (T0 as baseline data) and IR-RDPs at 1 week (T1), 6 weeks (T2) and 12 months (T3) post-insertion. Data analyses were based on intra-patient and inter-patient results. RESULTS: Masticatory performance and QoL improved with an IR-RDP at each time point. FMRI jaw clenching sensory and motor cortical activity decreased at T1, with motor cortical activity increasing to T0 levels at T2. For cognitive fMRI activation tasks, cortical activity decreased from T0 to T1 across all regions of interests (ROI) and increased at T2 throughout the cognitive brain regions. Neurocognitive skills declined at T1, followed by improvement to or beyond T0 levels at T2. CONCLUSION: Improvements in masticatory performance and OHQoL occurred from complete RDPs to IR-RDP. Prosthetic adaptation was associated with neurocognitive changes to pre-insertion activity levels or greater after 6 weeks. These pilot data suggest both behavioural and neural associations between POR and cognition; however, larger study numbers are required.

Neuroplasticity in the adaptation to prosthodontic treatment.

AIMS: To investigate cerebral cortical changes by using functional magnetic resonance imaging (fMRI) after denture renewal and to test how these relate to prosthodontic treatment adaptability as measured by chewing efficiency and maximum bite force. METHODS: Ten complete denture wearers (five women and five men, mean age ± standard deviation: 70.3 ± 9.1 years) participated in the study. Each had their complete dentures renewed and underwent an fMRI examination with three functional tasks (lip pursing; jaw tapping; jaw clenching) as well as a color-mixing test for chewing efficiency and unilateral maximum bite force measurements. Recordings were performed with the old dentures (T0) and with the new dentures on insertion (T1) and at 1 week (T2) and 3 months postinsertion (T3). At T1, denture stability and retention (S/T) were assessed by two independent operators. Wilcoxon signed rank tests and Spearman's rho correlation were carried out for data analysis. RESULTS: The right and the left precentral gyrus (PRCG) and postcentral gyrus (POCG) were identified with significant activation across all three functional tasks. A statistically significant increase in the level of activity between T0 and T2 (POCG: P = .022; PRCG: P = .017) was found during jaw clenching tasks. Both regions of interest (PRCG, POCG) appeared to correlate with S/T of the new dentures while the subject performed a lip-pursing task (PRCG: r = 0.689, P = .027; POCG: r = 0.665, P = .036). The chewing efficiency and maximum bite force increased significantly during the adaptation to replacement dentures (chewing efficiency: T1-T2 P = .032, T2-T3 P = .012; maximum bite force right side: T2-T3 P = .047). CONCLUSION: Changes in brain activity occurred in the adaptation to replacement dentures and appeared to regain preinsertion activity levels during motor tasks involving the dental occlusion after 3 months postinsertion.

Bone microarchitecture at oral implant sites in ectodermal dysplasia (ED): a comparison between males and females.

OBJECTIVE: The aim of this study was to analyse the microarchitecture of bone in association with implant placement in young ectodermal dysplasia (ED) patients. The general hypothesis was that the structural and morphological features of bone microarchitecture are different between males and females, which may influence clinical outcomes. MATERIALS AND METHODS: The bone harvesting is not additionally invasive, as the procedure was made at the time and site of implant placement. Twenty one samples (8 female, 13 male) were harvested from nine ED participants whose age ranged between 14 and 21 years and specified by the site of harvesting. Micro-CT analysis at 5 µm resolution was conducted on each sample. Specialized CT analysis of the three-dimensional (3-D) bone microstructure was made to compare structural parameters. In addition, two bone samples (one male, one female) were sent to the University of Michigan and analysed at 9 µm resolution. RESULTS: No significant difference was found between male and female samples. Bone analysis of particular sites revealed that bone-specific surface (BS/BV) was found to be significantly higher in male than in female samples, whilst the mean values of 10 parameters, the grey scale value histograms and 3-D visualization showed that female samples had higher compact density than male samples. CONCLUSION: Microstructural analyses indicated that female ED bone was more compact and with greater trabecular connectedness than male bone. These features may enhance resistance to external force transfer of mastication compared with male bone. Further bone samples from other jaw bone areas will provide information on whether there are regional differences in jawbone quality and quantity, which may influence implant treatment outcomes, as well as follow-up analyses of treatment outcomes.

Influence of implant abutment angulations and two types of fibers on the fracture resistance of ceramage single crowns.

PURPOSE: To assess the effect of three implant abutment angulations and two types of fibers on the fracture resistance of overlaying Ceramage single crowns. MATERIALS AND METHODS: Three groups, coded A to C, with different implant abutment angulations (group A/0°, group B/15°, and group C/30° angulation) were restored with 45 overlay composite restorations; 15 Ceramage crowns for each angulation. Groups A, B, and C were further subdivided into three subgroups (n = 5) coded: 1, crowns without fiber reinforcement; 2, crowns with Connect polyethylene reinforcement; and 3, crowns with Interlig glass reinforcement. All crowns were constructed by one technician using the Ceramage System. The definitive restorations (before cementation) were stored in distilled water at mouth temperature (37°C) for 24 hours prior to testing. Before testing, the crowns were cemented using Temp Bond. The compressive load required to break each crown and the mode of failure were recorded. The speed of testing was 1 mm/min. The results were statistically analyzed by two-way ANOVA (p < 0.05). The tested crowns were examined using a stereomicroscope at 40×, and selected crowns (five randomly selected from each group) were further examined by scanning electron microscopy (SEM) to reveal the composite-fiber interface. RESULTS: Fracture resistance of single crowns was not affected (p > 0.05) by the different abutment angulations chosen (0°, 15°, 30°) or fiber reinforcement (Connect and Interlig fibers). Crowns in group A exhibited average loads to fracture (N) of A1 = 843.57 ± 168.20, A2 = 1389.20 ± 193.40, and A3 = 968.00 ± 387.53, which were not significantly different (p > 0.05) from those of groups B (B1 = 993.20 ± 327.19, B2 = 1471.00 ± 311.68, B3 = 1408.40 ± 295.07), or group C (C1 = 1326.80 ± 785.30, C2 = 1322.20 ± 285.33, C3 = 1348.40 ± 527.21). SEM images of the fractured crowns showed that the origin of the fracture appeared to be located at the occlusal surfaces of the crowns, and the crack propagation tended to extend from the occlusal surface towards the gingival margin. CONCLUSIONS: Implant abutment angulations of 0°, 15°, and 30° did not significantly (p > 0.05) influence the fracture resistance of overlaying Ceramage single crowns constructed with or without reinforcing fibers. The two types of fibers used for reinforcement (Connect and Interlig) had no effect (p > 0.05) on the fracture resistance of overlaying Ceramage single crowns.

Benefits of Contemporary Rehabilitation of Edentulism: A Statement.

The purpose of this study was to review the impact of loss of teeth and the current state of treatment options available for oral rehabilitation of edentulism. Function with complete dental prostheses varies based on a patient's ability to adapt to removable prostheses and their psychologic acceptance of the treatment. There is varying dissatisfaction with removable prostheses, particularly in Western economies. This is driven in part by the availability of oral implants, which have transformed the treatment options for oral rehabilitation in general and for edentulous rehabilitation in particular. Quality-of-life studies have confirmed the advantages of implants for the retention and support of dental prostheses, as they improve function and esthetic measures to nearly those of the dentate state. Osseoperception, the concept of feedback to the sensorimotor system from tissues surrounding osseointegrated implants, contributes to enhanced function with implant treatment. It is recognized that tooth loss resulting in the loss of periodontal mechanoreceptors has a detrimental effect on jaw motor control even after implant treatment. However, despite this limitation, oral rehabilitation with or without implants, which improves function and esthetics, helps maintain psychosocial and cognitive health.

Quantifying the selection of maxillary anterior teeth using intraoral and extraoral anatomical landmarks.

BACKGROUND: One of the major hurdles in clinical prosthodontics has been the selection and replacement of maxillary anterior teeth in the absence of pre-extraction records. The aim of this study was to determine if a relationship exists between intraoral and extraoral facial measurements that could assist dental practitioners in selecting esthetically appropriate maxillary anterior teeth in the absence of pre-extraction records. MATERIALS AND METHODS: A cross-sectional study design was used with a sample size of one hundred and twenty participants. A questionnaire was used to identify the selection criteria and a photograph was taken for facial measurements using digitally calibrated software. Ninety-eight participants met the selection criteria and were included in the study. Measurements of intraoral landmarks were taken from stone casts of maxillary impressions using calibrated digital calipers. Each measurement was completed by two assessors to obtain mean values. Data were statistically analyzed using SPSS version 17 software. Data were assessed by one way analysis of variance (ANOVA) followed by post hoc (p < 0.05) to find any difference between tested groups. Pearson coefficients were used to determine whether correlation exists between measurements. RESULTS: The mean values for intraoral maxillary landmarks were: Central incisor width = 8.39 mm, circumferential canine tip to canine tip distance = 34.89 mm, arch width = 48.24 mm, left arch length = 45.24 mm, right arch length = 45.56 mm. The mean values for extraoral landmarks were: Intercanthal distance = 33.24 mm, interpupillary distance = 60.68 mm, interalar distance = 38.27 mm, intercommissure distance = 50.61 mm. Differences existed within subgroups for all intraoral and extraoral measures. A weak positive correlation existed between intraoral (r < 0.4) and extraoral measurements (r < 0.38) that remained consistent when examined by gender. CONCLUSION: This study showed that the average length and width of the maxillary arch and interalar width were the anatomical landmarks that provided the strongest predictive relationship with anterior maxillary teeth (r = 0.38 - 0.4). Using these dimensions an average multiplying factor can be used to calculate maxillary incisor width or canine tip to canine tip distance. As the predictive strength is not strong, the authors recommend its use as a preliminary guide for determining the width of the maxillary anterior teeth during the initial selection of artificial teeth in the absence of pre-extraction records. CLINICAL SIGNIFICANCE: The results of this study can be used to help dentists select the size of artificial maxillary anterior teeth in the absence of pre-extraction records.

Changes in human primary motor cortex activity during acute cutaneous and muscle orofacial pain.

AIMS: To use functional magnetic resonance imaging (fMRI) to determine whether orofacial cutaneous or muscle pain is associated with changes in primary motor cortex (M1) activity that outlast the duration of perceived pain, and whether these M1 changes are different during cutaneous pain compared with muscle pain. METHODS: fMRI was used in healthy subjects experiencing orofacial muscle (n = 17) or cutaneous (n = 15) pain induced by bolus injections of hypertonic saline (4.5%) into the belly of the masseter muscle (0.5 ml) or subcutaneously (0.2 ml) into the overlying skin, respectively. To determine the effects of the injection volume, isotonic saline (n = 4) was injected into the masseter muscle. RESULTS: Similar pain scores were observed following subcutaneous (mean [± SEM]; 4.73 ± 0.51) or intramuscular injections (4.35 ± 0.56). Orofacial muscle but not cutaneous pain was associated with a transient increase in signal intensity in the contralateral M1. Cutaneous and muscle orofacial pains were associated with similar signal intensity decreases within the contralateral M1 that continued to decrease for the entire scanning period. Isotonic saline did not evoke pain or changes in M1 signal intensity. CONCLUSION: The transient contralateral M1 signal intensity increase during orofacial muscle pain may underlie escape-like motor patterns. However, once the initial threat has subsided, longer-term reductions in M1 activity and/or excitability may occur to aid in minimizing movement of the affected part, an effect consistent with the general proposals of the Pain Adaptation Model.

A diet high in fat and fructose adversely affects osseointegration of titanium implants in rats.

OBJECTIVES: Diet-induced metabolic dysfunction such as type 2 diabetes mellitus increases the risk of implant failure in both dental and orthopaedic settings. We hypothesised that a diet high in fat and fructose would adversely affect peri-implant bone structure and function including osseointegration. MATERIALS AND METHODS: Thirty female Sprague-Dawley rats were divided into three groups (n = 10), control group (normal chow) and two intervention groups on a high-fat (60%), high-fructose (20%; HFHF) diet. Titanium implants were placed in the proximal tibial metaphysis in all groups either before commencing the diet (dHFHF group) or 6 weeks after commencing the diet (HFHF group) and observed for an 8-week healing period. Fasting blood glucose levels (fBGLs) were measured weekly. Structural and functional features of the peri-implant bone, including bone-to-implant contact (BIC), were analysed post euthanasia using microcomputed tomography, pull-out tests, and dynamic histomorphometry. RESULTS: The fBGLs were unchanged across all groups. Peri-implant trabecular bone volume was reduced in the HFHF group compared with controls (p = .02). Percentage BIC was reduced in both HFHF group (25.42 ± 3.61) and dHFHF group (28.56 ± 4.07) compared with the control group (43.26 ± 3.58, p < .05) and reflected the lower pull-out loads required in those groups. Osteoblast activity was reduced in both intervention groups compared with the control group (p < .05). CONCLUSION: The HFHF diet compromised osseointegration regardless of whether the implant was placed before or after the onset of the diet and, despite the absence of elevated fBGLs, confirming that changes in bone cell function affected both the initiation and maintenance of osseointegration independent of blood glucose levels.

Differential activation of the human trigeminal nuclear complex by noxious and non-noxious orofacial stimulation.

There is good evidence from animal studies for segregation in the processing of non-nociceptive and nociceptive information within the trigeminal brainstem sensory nuclear complex. However, it remains unknown whether a similar segregation occurs in humans, and a recent tract tracing study suggests that this segregation may not exist. We used functional magnetic resonance imaging (fMRI) to define and compare activity patterns of the trigeminal brainstem nuclear complex during non-noxious and noxious cutaneous and non-noxious and noxious muscle orofacial stimulation in humans. We found that during cutaneous pain, signal intensity increased within the entire rostrocaudal extent of the spinal trigeminal nucleus (SpV), encompassing the ipsilateral oralis (SpVo), interpolaris (SpVi) and caudalis (SpVc) subdivisions. In contrast, muscle pain did not activate SpVi, but instead activated a discrete region of the ipsilateral SpVo and SpVc. Further, muscle noxious stimulation activated a region of the ipsilateral lateral pons in the region of the trigeminal principal sensory nucleus (Vp). Innocuous orofacial stimulation (lip brushing) also evoked a significant increase in signal intensity in the ipsilateral Vp; however, non-noxious muscle stimulation showed no increase in signal in this area. The data reveal that orofacial cutaneous and muscle nociceptive information and innocuous cutaneous stimulation are differentially represented within the trigeminal nuclear complex. It is well established that cutaneous and muscle noxious stimuli evoke different perceptual, behavioural and cardiovascular changes. We speculate that the differential activation evoked by cutaneous and muscle noxious stimuli within the trigeminal sensory complex may contribute to the neural basis for these differences.

Experimental jaw-muscle pain has a differential effect on different jaw movement tasks.

AIMS: To determine the effects of experimental jaw-muscle pain on jaw movements. METHODS: Mandibular mid-incisor point was tracked in 22 asymptomatic subjects during standardized (at 2.2 mm/s) protrusion, contralateral excursion, and open jaw movements, as well as free, right-sided chewing and chewing standardized for timing (900 ms/cycle). Tonic infusion of 4.5% hypertonic saline into the right masseter muscle maintained pain intensity between 30 and 60 mm on a 100-mm visual analog scale. Subjects performed tasks in 3 sessions on the same experimental day: control condition (baseline trials), test condition 1 (during hypertonic or 0.9% isotonic saline infusion), and test condition 2 (during isotonic or hypertonic saline infusion). RESULTS: In comparison with control, there were no significant effects of hypertonic saline infusion on amplitude or velocity for protrusion or contralateral jaw movements or on velocity for jaw opening. Jaw-opening amplitude was significantly smaller in comparison with control during hypertonic, but not isotonic, saline infusion. During free but not standardized chewing, subjects chewed faster and exhibited larger amplitude gapes during hypertonic and isotonic infusion in comparison with control. Therefore, it was unlikely that pain had an effect on the kinematic parameters of jaw movement during free chewing. Qualitatively, individual subject data revealed considerable variability in the effects of hypertonic saline on movement parameters, which suggests that the effect of pain on jaw movement may not be uniform between individuals. CONCLUSIONS: The data indicate that the effect of pain on jaw movement may vary with the task performed.

On Implant Prosthodontics: One Narrative, Twelve Voices - 5.

No abstract available.

A Within-Subject Comparison of Patient Satisfaction and Quality of Life Between a Two-Implant Overdenture and a Three-Implant-Supported Fixed Dental Prosthesis in the Mandible.

PURPOSE: This within-subject comparison tested the null hypothesis that there is no difference in patient satisfaction and oral health-related quality of life when an individual with an edentulous mandible is rehabilitated with a two-implant overdenture or a three-implant-supported fixed dental prosthesis. MATERIALS AND METHODS: Twelve subjects with an edentulous mandible or failing dentition were rehabilitated with the use of endosseous dental implants. Three implants were placed, and were immediately loaded with a provisional fixed prosthesis with minimal cantilever. After healing for 4 months, two Locator attachments were inserted and an overdenture was trialed; then, after a further 4 months, a fixed prosthesis was placed on the three implants. The fixed prosthesis was fabricated using computer-assisted design, and a titanium framework was manufactured with a resin base and teeth. Patient satisfaction and oral health-related quality of life was assessed before treatment, after wearing the provisional, and after each treatment option using a seven-item visual analog scale and a modified version of the 49-item oral health impact profile. RESULTS: Of the 12 subjects, 11 chose the fixed over the removable prosthesis. A statistically significant (P < .05) and positive effect on the overall score of both assessment tools was reported for both treatment modalities (when compared with pretreatment scores). Although no significant difference (P > .05) was found between the two options in overall scores of both surveys or in any of the seven domains of the modified oral health impact profile, the fixed prosthesis had a statistically higher score for stability, retention, and ease of chewing on a visual analog scale. CONCLUSION: Both treatment modalities provided a significant and similar improvement in patient satisfaction and oral health-related quality of life compared with a conventional complete mandibular removable dental prosthesis; however, a statistically significant higher score was reported for stability, retention, and ease of chewing for the fixed dental prostheses. Based on the 12 participants in this study, greater stability and ease of chewing with the fixed prosthesis likely influenced patient preference in most but not all subjects.

Rehabilitation of ectodermal dysplasia patients presenting with hypodontia: outcomes of implant rehabilitation part 1.

PURPOSE: This study has evaluated the pre and post perceptions of patients with ectodermal dysplasia (ED) who have been referred to Westmead Centre for Oral Health for treatment with dental implants. METHODS: Six patients with ED and hypodontia were treated with new maxillary complete dental prostheses or fixed implant prostheses, and a mandibular fixed dental prosthesis with implants. Patient perceptions were recorded with a 10cm visual analogue scale (VAS). All patients were asked to draw a line on the VAS which best described their feelings regarding aesthetics, chewing, diet and speech. RESULTS: Improvement in aesthetics was reported for all patients with change scores ranging from +9 to +4 points. Similarly, all patients reported an improvement in chewing ability with +6 point changes in 2 patients, and +8, +3, +7 and +1 in the other 4 patients. Five out of 6 patients reported less dietary restriction with 3 patients each indicating a change of +6 points, +4 points, +3 points, and 2 patients reporting +1 point change. Speech improved by +1 point for 3 patients, whilst 1 patient improved by +6 points, a further 2 patients scored no change. CONCLUSIONS: Patients with ED treated with dental implants reported encouraging outcomes post treatment after prostheses were fitted. Follow-up from 1.6 to 6.8 years has confirmed these improvements.

Hematologic and urinary excretion anomalies in patients with chronic fatigue syndrome.

Patients with chronic fatigue syndrome (CFS) have a broad and variable spectrum of signs and symptoms with variable onsets. This report outlines the results of a single-blind, cross-sectional research project that extensively investigated a large cohort of 100 CFS patients and 82 non fatigued control subjects with the aim of performing a case-control evaluation of alterations in standard blood parameters and urinary amino and organic acid excretion profiles. Blood biochemistry and full blood counts were unremarkable and fell within normal laboratory ranges. However, the case-control comparison of the blood cell data revealed that CFS patients had a significant decrease in red cell distribution width and increases in mean platelet volume, neutrophil counts, and the neutrophil-lymphocyte ratio. Evaluation of the urine excretion parameters also revealed a number of anomalies. The overnight urine output and rate of amino acid excretion were both reduced in the CFS group (P < 0.01). Significant decreases in the urinary excretion of asparagine (P < 0.0001), phenylalanine (P < 0.003), the branch chain amino acids (P < 0.005), and succinic acid (P < 0.0001), as well as increases in 3-methylhistidine (P < 0.05) and tyrosine (P < 0.05) were observed. It was concluded that the urinary excretion and blood parameters data supported the hypothesis that alterations in physiologic homeostasis exist in CFS patients.

Rehabilitation of a patient diagnosed with Ectodermal Dysplasia presenting hypodontia: a case report

Purpose: The study showed a patient with Ectodermal Dysplasia (ED) who was treated with implants and fixed dental prosthesis by a multidisciplinary team. Case Report: Acrylic resin dental prostheses were designed as long-term provisionals, which allowed modifications when required. After imaging and treatment planning, four implants were placed in the inter-foramenal area of the mandible and 2 years later the definitive prosthesis was fitted. In a second phase, the patient received a combination of autogenous and allogeneic bone grafts in the maxilla. The autogenous graft was removed from the retro-molar region in the mandible. He also received a fixed dental prosthesis supported by 4 implants on the position of the upper canines and second pre-molars. Conclusion: Patient reports successful outcomes and despite the long treatment, patient states is confident with his appearance and speaking improvement. Follow-up was done every six months, for 10 years, and showed encouraging post-treatment outcomes.

Assisted Wound Healing and Vertical Bone Regeneration with Simultaneous Implant Placement: A Histologic Pilot Study.

PURPOSE: To evaluate the effectiveness of platelet-rich fibrin (PRF) and freeze-dried bone allograft (FDBA) in vertical bone augmentation with immediate implant placement using histologic analysis. MATERIALS AND METHODS: Six Merino sheep received a total of 36 Brånemark MKIII implants; three implants were placed supracrestally in each tibia with vertical exposure of four threads. Each implant received one of the three grafting options (MinerOss + PRF or MinerOss or PRF). The grafting materials were covered with a resorbable collagen membrane (Mem-Lok 30 × 40 mm, BioHorizons). Animals were sacrificed at 4 and 8 weeks, respectively, and specimens were prepared and collected for histologic analysis. Ground sections and decalcified sections were prepared. RESULTS: The various stages of graft integration into native bone and the implant were observed at different time points, and comparison between the three grafting options was possible. Osteogenic potential with vertical generation of bone was observed in the three groups. At week 4, woven bone formation at the bone graft interface was observed; new bone did not appear to be organized at week 4. At week 8, the graft appeared to be fully replaced by vital mature and well-organized bone arranged in lamellae with osteocytes encapsulated within the bone. The vertical bone gain at 8 weeks was higher for the PRF + MinerOss group with viable bone extending above the first thread. Both the MinerOss and PRF groups had vertical bone gain extended to the second thread. CONCLUSION: MinerOss appeared to be effective in vertical bone augmentation with simultaneous implant placement. PRF enhanced vertical bone augmentation when combined with MinerOss.

The effect of hyperglycaemia on osseointegration: a review of animal models of diabetes mellitus and titanium implant placement.

UNLABELLED: Patients with type 2 diabetes mellitus have a higher risk of dental and/or orthopaedic implant failure. However, the mechanism behind this phenomenon is unclear, and animal studies may prove useful in shedding light on the processes involved. This review considers the available literature on rat models of diabetes and titanium implantation. INTRODUCTION: The process of osseointegration whereby direct contact is achieved between bone and an implant surface depends on healthy bone metabolism. Collective evidence suggests that hyperglycaemia adversely affects bone turnover and the quality of the organic matrix resulting in an overall deterioration in the quality, resilience and structure of the bone tissue. This in turn results in compromised osseointegration in patients receiving dental and orthopaedic implants. The incidence of diabetes mellitus (DM), which is a chronic metabolic disorder resulting in hyperglycaemia, is rising. Of particular significance is the rising incidence of adult onset type 2 diabetes mellitus (T2DM) in an ageing population. Understanding the effects of hyperglycaemia on osseointegration will enable clinicians to manage health outcomes for patients receiving implants. Much of our understanding of how hyperglycaemia affects osseointegration comes from animal studies. METHODS: In this review, we critically analyse the current animal studies. RESULTS: Our review has found that most studies used a type 1 diabetes mellitus (T1DM) rodent model and looked at a young male population of rodents. The pathophysiology of T1DM is however very different to that of T2DM and is not representative of T2DM, the incidence of which is rising in the ageing adult population. Genetically modified rats have been used to model T2DM, but none of these studies have included female rats and the metabolic changes in bone for some of these models used are not adequately characterized. CONCLUSIONS: Therefore, the review suggests that the study population needs to be broadened to include both T1DM and T2DM models, older rats as well as young rats, and importantly animals from both sexes to reflect more accurately clinical practice.

Surface roughness of restoration margin preparations: a comparative analysis of finishing techniques.

This study compared the margin profile and surface roughness created by the tips of four different finishing instruments: fine diamond, dura white stone, tungsten carbide, and ultrasonic diamond-coated tips (UDTs). The aim was to determine which of these instruments produced the smoothest finish and created the most evenly contoured margin characteristics. It was hypothesized that UDTs would produce a rougher dentin surface than a fine diamond bur, that a tungsten carbide bur would provide a smoother finish than a fine diamond, and that the dura white stone would produce an intermediate finish. Forty extracted premolars were divided into two groups. For the first group, a 1.5 x 3.0-mm dentin slot was prepared in 30 teeth using a control 50-µm diamond bur, followed by one of the four finishing instruments. The surface roughness (Ra) was then measured using a surface profilometer and a one-way analysis of variance followed by a post hoc Bonferroni test to assess whether any statistical difference existed among the Ra values. For the second group, shoulder margins were prepared in 10 teeth. They were then refined with one of the four finishing instruments and examined with scanning electron microscopy (SEM). The fine diamond bur created a significantly smoother surface than the control diamond (P < .001), UDTs (P < .007), and tungsten carbide bur (P < .010). The fine diamond was not found to be significantly smoother than the dura white stone. SEM images of the fine diamond showed divoting on the margin floor. The dura stone showed a well-defined, undamaged margin. The tungsten carbide bur created frequent chipping in enamel margins. The UDT specimens showed an inconsistent finish and discrete patches of open dentinal tubules. The fine diamond created the lowest Ra values; however, the dura stone offered efficient finishing and less damage to the margin profile.