The biomechanical principles of restoring a dentition with dental implants: A General Dental Practitioner's perspective.

Dental implants continue to increase in popularity as a method of replacing missing or failing teeth and, in doing so, this increased prevalence is likely to present as a range of scenarios for the general dental practitioner and dental hygienist, whether they have an interest in the field or not. Many of these scenarios will relate to the restorative and post-treatment phases of treatment, where the biomechanical performance of the restoration will need to be understood by the treating clinician in the primary care setting. This article aims to highlight the unique biomechanical nature of dental implant restorations, the differences between a natural tooth held by periodontal ligament fibres and a dental implant ankylosed to bone, the consideration of restoring a natural tooth opposing a dental implant, and the long-term effect of changes in the occlusion and their impact on previously placed dental implant restorations.

Prognostic value of CD44 expression in oral squamous cell carcinoma: A meta-analysis.

CD44 as a marker of cancer stem cells (CSCs) may be correlated with tumor growth, cell migration, metastasis and chemo-radiotherapy resistance of cancers. However, the prognostic value of CD44 in oral squamous cell carcinoma(OSCC) remains controversial. Therefore, the purpose of the current study was to evaluate the correlation of CD44 expression with the prognosis of OSCC through a meta-analysis. We systematically searched PubMed, Scopus, ISI Web of Science, Embase and Cochrane Central databases for relevant studies up to November 2022. We included 11 articles with immunohistochemistry (IHC) method involving 1084 OSCC patients. Hazard ratios (HRs) with 95 % confidence intervals (95 % CIs) were calculated to assess the association between CD44 expression and overall survival (OS) and disease-free survival (DFS). Results showed that high expression of CD44 was a poor prognostic marker for OS in OSCC patients (HR: 1.71, 95 % CI: 1.18-2.47). Also results for DFS demonstrated that in patients with high CD44 expression who received treatment, the probability of tumor recurrence or death was 1.66 times and in the worst case this ratio can reach 2.39 (HR: 1.66, 95 % CI: 1.15-2.39). High CD44 expression associated with metastasis to lymph nodes and distant metastasis, poorer survival of the patients, tumor recurrence, higher tumor stage and grade and aggressive clinicopathological features. Therefore CD44 can be used as a valuable independent marker in predicting the prognosis of OSCC patients.

Indications for the use of direct composite restorations in the management of tooth wear.

The increasing prevalence of tooth surface loss has been widely reported. Patients present with varying degrees of tooth wear and consideration is given to whether a prevention and monitoring approach, or a treatment and restoration approach, is appropriate. A missed diagnosis or excessively prolonged monitoring risks progression to the detriment of a successful outcome, with the potential compromise on the quality and quantity of tooth structure available for predictable adhesive dentistry. Direct composite resin (DCR) restorations can be considered as a viable treatment option for all extents of tooth wear, including cases that have progressed to a severe degree. This paper aims to review the indications for DCR restorations in the management of tooth wear, using clinical cases to demonstrate their effectiveness.

Clinical considerations in the application of direct composite for tooth wear.

Various techniques are available for the application of composite to restore worn teeth. Different techniques may be chosen based on the clinical presentation or clinician preference. However, for composite to be successful, there are numerous factors which must be considered in order to optimise the outcome. Pre-treatment steps, such as isolation for optimal moisture control and adequate surface preparation of the tooth, as well as the post build-up objectives of achieving a stable occlusion, good marginal adaptation and final aesthetics, are discussed in the paper.

Smile makeover treatments.

The demand for aesthetic smile makeover treatments is increasing, especially with the rise in social media use. Historically, healthy tooth structure was sacrificed in order to achieve rapid results but this would invariably lead to compromise of the occlusion and a less-than-ideal result.Multi-disciplinary treatment planning, including the use of orthodontic treatment, is now routinely used in order to achieve optimal results. This paper aims to highlight the importance of a combined orthodontic-restorative planning process to allow a long-term aesthetic and functional result for our patients.

Occlusion: is there a third way? A discussion paper.

This paper does not set out to describe the reasons why a new concept of dental care should be deemed as acceptable and recognised as mainstream. Rather, the starting point of this paper is the belief that some dentists who are increasing the overall vertical dimension for worn dentition patients are not using the protocols of the traditional 're-organised approach'. If adhesive direct restorations are used, there seems to be anecdotal indication that despite not restoring in the terminal hinge axis, it can have a successful outcome.So, while not criticising this approach simply because it does not follow orthodoxy, the paper has two objectives. It hopes to stimulate some debate and research on this subject. Furthermore, by suggesting some parameters for what might be considered a new approach, it aims to improve patient outcome.

Discoloration and force degradation of orthodontic elastomeric ligatures.

OBJECTIVE:: The aim of the present study was to evaluate color changes and force degradation of orthodontic elastomeric ligatures in different stretching patterns during a 8-weeks period. METHODS:: Two elastomers with the minimum and two with the maximum color changing, and gray elastomers of two brands (American Orthodontics and Ortho Technology) were selected according to an opinion poll with clinicians and color changes after 4 weeks of intraoral use were evaluated. These elastomers were mounted on special jigs fabricated using a CAD-CAM technique, underwent different stretching patterns and the force was measured in 0, 24 hours, 2, 4 and 8 weeks. During in vivo part of the study, force levels of elastomers were measured after 4 weeks on a material testing machine. Data were analyzed with four-way ANOVA and Tukey post hoc tests. RESULTS:: All the elastomers showed color changing but the degree of color stability was significantly different. The mean force degradation was higher in 1-mm stretch groups. After 8 weeks, the average residual force of elastomers was 1.45 ± 0.18 N and the maximum force decay was seen in the elastomers that exhibited the maximum initial force. CONCLUSION:: There is significant relationship between the stretching pattern and the amount of residual force of elastomers. Elastomers with higher initial forces exhibited higher percentages of force loss after 8 weeks. It seems that there is a relationship between initial color and color changing of elastomers.

Cl II Malocclusion Treatment, Using the Modified Twin Block Appliance Coordinated with Fixed Orthodontics in a Postmenarche Patient.

Functional appliances have been used for treatment of Class II patients for a long time. The main objective of therapy with functional appliances is to induce supplementary lengthening of the mandible by stimulating increased growth at the condylar cartilage. The Twin Block appliance is one of the most commonly used functional appliances. The aim of this paper is to present a case report of mandibular deficiency treatment with Twin Block appliance in a female patient whose sexual maturation (one and a half years after menarche) and cervical vertebral maturation stage indicated the end of the growth peak. The treatment started with bonding 0.022 in MBT prescription brackets on the upper arch in order to align upper teeth and create a symmetric overjet. When reaching alignment, a modified Twin Block was given to the patient for 8 months. Final coordination was achieved with fixed appliances in both arches. At the end of the treatment, profile of the patient improved, crowding was relieved, and Cl I relationship with normal overjet and overbite was achieved.

Discoloration and force degradation of orthodontic elastomeric ligatures

ABSTRACT OBJECTIVE: The aim of the present study was to evaluate color changes and force degradation of orthodontic elastomeric ligatures in different stretching patterns during a 8-weeks period. METHODS: Two elastomers with the minimum and two with the maximum color changing, and gray elastomers of two brands (American Orthodontics and Ortho Technology) were selected according to an opinion poll with clinicians and color changes after 4 weeks of intraoral use were evaluated. These elastomers were mounted on special jigs fabricated using a CAD-CAM technique, underwent different stretching patterns and the force was measured in 0, 24 hours, 2, 4 and 8 weeks. During in vivo part of the study, force levels of elastomers were measured after 4 weeks on a material testing machine. Data were analyzed with four-way ANOVA and Tukey post hoc tests. RESULTS: All the elastomers showed color changing but the degree of color stability was significantly different. The mean force degradation was higher in 1-mm stretch groups. After 8 weeks, the average residual force of elastomers was 1.45 ± 0.18 N and the maximum force decay was seen in the elastomers that exhibited the maximum initial force. CONCLUSION: There is significant relationship between the stretching pattern and the amount of residual force of elastomers. Elastomers with higher initial forces exhibited higher percentages of force loss after 8 weeks. It seems that there is a relationship between initial color and color changing of elastomers.

RESUMO OBJETIVO: o objetivo do presente estudo foi avaliar as alterações de cor e a degradação da força de ligaduras elásticas em diferentes padrões de estiramento, durante um período de 8 semanas. MÉTODOS: duas ligaduras elásticas com alteração mínima de cor, duas com alteração máxima de cor e ligaduras elásticas na cor cinza de duas marcas comerciais (American Orthodontics e Ortho Technology) foram selecionadas de acordo com uma pesquisa de opinião com clínicos, e mediante a avaliação das alterações de cor após quatro semanas em uso intrabucal. Essas ligaduras elásticas foram montadas em jigs fabricados por meio da técnica CAD-CAM e foram expostas a diferentes padrões de estiramento, e a força foi medida nos tempos de 0h, 24h; 2, 4 e 8 semanas. Durante a parte in vivo do estudo, os níveis de força das ligaduras elásticas foram medidos após 4 semanas, em uma máquina de teste de materiais. Os dados foram analisados com os testes ANOVA de quatro vias e post-hoc de Turkey. RESULTADOS: todas as ligaduras elásticas mostraram alterações de cor, mas houve diferenças significativas quanto ao grau de estabilidade da cor. A média de degradação da força foi mais alta nos grupos com estiramento a 1 mm. Após 8 semanas, a média da força residual nas ligaduras elásticas foi de 1,45 ± 0,18 N e a maior degradação na força foi observada nas ligaduras elásticas que apresentaram a maior força inicial. CONCLUSÃO: há uma relação significativa entre o padrão de estiramento e a quantidade de força residual nas ligaduras elásticas. As ligaduras elásticas com as maiores forças iniciais exibiram as mais altas porcentagens de degradação da força após 8 semanas. É, também, possível que haja uma relação entre a cor inicial da ligadura elástica e sua alteração de cor.

Dental complications of gastro-oesophageal reflux disease: guidance for physicians.

There is potential for gastro-oesophageal reflux disease (GORD) to be under-diagnosed by physicians. A quick, focused examination, requiring no special equipment, of a patients' dentition can assist in making a more accurate diagnosis where GORD is suspected. Guidance is provided for physicians as to what intra-oral signs are suggestive of intrinsic dental erosion, which is a clinical feature of GORD and its associated conditions. Use of this information will, it is suggested, improve outcomes for patients where GORD is suspected.

Evaluation of the effect of different stretching patterns on force decay and tensile properties of elastomeric ligatures.

BACKGROUND: There have been numerous researches on elastomeric ligatures, but clinical conditions in different stages of treatment are not exactly similar to laboratory conditions. The aim of this in vitro study was to simulate clinical conditions and evaluate the effect of three stretching patterns on the amount of force, tensile strength (TS) and extension to TS of the elastomers during 8 weeks. MATERIALS AND METHODS: Forces, TS and extension to TS of two different brands of elastomers were measured at initial, 24 h and 2, 4, and 8-week intervals using a testing machine. During the study period, the elastomers were stored in three different types of jig (uniform stretching, 1 and 3 mm point stretching) designed by the computer-aided design and computer-aided manufacturing technique in order to simulate the different stages of orthodontic treatment. RESULTS: The elastomeric ligatures under study exhibited a similar force decay pattern. The maximum force decay occurred during the first 24 h (49.9% ± 15%) and the amount of force decay was 75.7% ± 8% after 8 weeks. In general, the TS decreased during the study period, and the amount of extension to TS increased. CONCLUSION: Although the elastic behavior of all ligatures under study was similar, the amount of residual force, TS and extension to TS increased in elastomers under point stretching pattern.

Validity and reliability of a three-dimensional dental cast simulator for arch dimension measurements.

BACKGROUND: The accuracy and reproducibility of measurements in a locally made three dimensional (3D) simulator was assessed and compared with manual caliper measurements. MATERIALS AND METHODS: A total of 20 casts were scanned by our laser scanner. Software capabilities included dimensional measurements, transformation and rotation of the cast as a whole, separation and rotation of each tooth and clip far. Two orthodontists measured the intercanine width, intermolar width and canine, molar and arch depth on the casts and in 3D simulator. For calculating the reliability coefficient and comparing random and systematic errors between the two methods, intra-class correlation coefficient of reliability (ICC), Dahlberg and paired t-test were used, respectively. The ICC and Dahlberg's formula were also applied to assess intra-examiner and inter-examiner reliability of measurements on the casts and in the simulator (P < 0.05). RESULTS: Canine and molar depth measurements had low reliability on the casts. Reliability between methods for the remaining three variables was 0.87, 0.98 and 0.98 in the maxilla and 0.92, 0.77 and 0.94 in the mandible, respectively. The method error was between 0.31 and 0.48 mm. The mean intra-observer difference were 0.086 and 0.23 mm in the 3D method and caliper. The inter-observer differences were 0.21 and 0.42 mm, respectively. CONCLUSION: The maximum average absolute difference between the two methods was <0.5 mm, indicating that the new system is indeed clinically acceptable. The examiner reliability was higher in 3D measurements.

Implant placement in patients with oral bisphosphonate therapy: a case series.

BACKGROUND: Although the effect of bisphosphonates on dental implant osseointegration is not clear, dental implant failures attributable to oral bisphosphonate therapy have been reported in patients with osteoporosis. PURPOSE: The aim of this study was to evaluate implant survival in patients with a history of bisphosphonate therapy in a retrospective survey. MATERIALS AND METHODS: A total of 46 ITI implants placed in 21 osteoporotic patients (females; average age 53 years, range 42-79 years) were evaluated with regard to probing depth, mobility, thread exposure, and bleeding on probing. All patients were under oral bisphosphonate therapy. RESULTS: None of implants showed mobility and all patients could be considered free from peri-implantitis. Time of bisphosphonate therapy before and after implant insertion showed no statistically significant influence on PD, BOP, and TE. Likewise, implant location, prosthetic type, and opposing dentition had no statistically significant influence on the clinical and radiological parameters of implants. CONCLUSION: Within the limitations of this study, it could be concluded that neither being on oral bisphosphonate treatment before implant placement nor starting bisphosphonate therapy after implant installation might jeopardize the successful osseointegration and clinical and radiographic condition of the implants.

Vital tooth bleaching in dental practice: 3. Biological, dental and legal issues.

UNLABELLED: The final section of this series examines both the evidence for the safety of external bleaching with hydrogen peroxide and related products and the legal position in the UK with regard to their sale and use in general dental practice. Potential side-effects are examined, including biological effects and dental effects, with a review of the current evidence. The EU Cosmetics and Medical Device Directive are both described and their impact on the provision of tooth bleaching in the UK is explained. The legal position in the UK renders the sale and supply of solutions containing >0.1% peroxide illegal, and practitioners must be aware of the underlying legislation and the basis upon which a prosecution may be pursued. CLINICAL RELEVANCE: Clinicians considering using hydrogen peroxide products must be aware of the safety issues surrounding their use and be able to explain to patients the nature of the risk and also the likelihood of any given patient experiencing them.

Vital tooth bleaching in dental practice: 2. Novel bleaching systems.

UNLABELLED: This paper describes some of the novel commercial approaches to tooth bleaching. Known as 'direct-to-consumer' products there are two main systems available, one employing coated, cellulose strips and the other a paint-on gel. A further development is the production of dentifrices that contain active hydrogen peroxide, made possible by the use of dual chambered tubes. Each of the systems is described and demonstrated and an overview of the research supporting their safe, effective use is presented in each case. It is likely that our patients have access to these products and, hence, it is important that we are aware of their strengths and weaknesses. CLINICAL RELEVANCE: The systems described within this paper are available for sale in Europe and over the internet. Patients may well be using, or planning to use, them and may ask for professional advice.

Vital tooth bleaching in dental practice: 1. Professional bleaching.

UNLABELLED: As dental health improves, with the concurrent drop in the provision of basic restorative care, patients are now asking their dentists to provide aesthetic treatments rather than the treatment of disease. Tooth bleaching is one such treatment that is frequently described in consumer magazines and television shows, driving consumer interest in this, apparently, benign therapy. This three-part series demonstrates the techniques that can be employed, within the dental practice or under the supervision of a clinician, those systems that can be bought by patients over the counter and, finally, a discussion of the biological effects of peroxide-containing solutions and the legal position on such products in the UK. In this section, we will describe the common methods by which teeth can be bleached, either by the clinician directly, or under his/her supervision by the use of'at home' kits. Efficacy and safety issues will be described. CLINICAL RELEVANCE: Clinicians should be able to discuss the merits, risks and likely success of a variety of bleaching treatments with their patients and, in doing so, assist in the process of obtaining informed consent.

A comparison of the depths produced using three different tooth preparation techniques.

STATEMENT OF PROBLEM: Inadequate preparation of teeth for metal ceramic crowns can significantly influence the ultimate form and longevity of the definitive restoration, as well as adversely affect the supporting tissues. PURPOSE: The purpose of the study was to determine the effect that 3 different tooth preparation techniques had on an operator's ability to appropriately and consistently prepare teeth for metal ceramic crowns. MATERIAL AND METHODS: Thirty typodont maxillary central incisor teeth were mounted individually and randomly allocated to 3 equal groups (A, B, and C). One operator was asked to prepare each tooth for a metal ceramic crown. A freehand approach was used to prepare the teeth in Group A, which acted as a control. Groups B and C were prepared with the assistance of a silicone index and a suitable depth gauge bur, respectively. A silicone index of the unprepared tooth, into which contrasting silicone was injected to occupy the space created by tooth preparation, was sectioned in the midline. Images of the sectioned index were captured with an optical microscope (resolution +/- 0.02 mm), which was attached to a personal computer. A calibrated image analysis program was used to measure the depth of preparation (in millimeters) at 5 points (labial cervical, mid-labial, incisal, mid-palatal, and palatal cervical) on 2 occasions. These results were pooled and averaged to give a mean labial and palatal preparation depth (in millimeters) and incisal edge reduction. The data were analyzed by use of a 1-way analysis of variance and Scheffe's post hoc statistical test (P<.05). RESULTS: The mean depths of labial and palatal preparation for Groups A, B, and C were 1.28 and 0.47 mm; 1.46 and 0.56 mm; and 1.45 and 0.63 mm, respectively. The difference between the groups' labial preparation depth was not significant (P=.06), but the difference for palatal preparation depth was significant (P=.01). The mean incisal reduction was 3.00 mm for Group A, 2.74 mm for Group B, and 2.13 mm for Group C (P=.00). CONCLUSION: Within the limitations of this study, it was concluded that preparation of teeth for metal ceramic crowns without the use of devices to help gauge reduction depth can result in insufficient labial reduction and incisal overreduction.