Impact of Removable Partial Dentures on Masticatory Performance in Partial Edentulism: A Systematic Review

PURPOSE

Removable partial dentures (RPDs) are widely used in clinical dental practice as a cost-effective treatment to restore the oral function. Clear understanding of the effect of partial dentures on masticatory performance is important for clinical decision making in prosthodontics. The purpose of this systematic review is to evaluate the impact of RPDs on masticatory performance (MP) of partially edentulous subjects.

MATERIAL AND METHODS

Electronic database and hand searches were conducted to explore clinical trials reporting the evidence of the effect of metal and acrylic based removable partial dentures on mastication. The validated objective and subjective measures of assessment of mastication were included. The article selection, data extraction and assessment of risk of bias were conducted by two reviewers independently.

RESULTS

Out of 11200 studies, one randomised control trial and 23 clinical trials met the inclusion criteria. Positive impact on different parameters of masticatory function after RPD treatment, was reported in 14 studies. Subjective evaluation of chewing ability (CA) displayed an improvement in 83.3% of studies, while improvement was evidenced only in 69.5% of studies upon objective evaluation. Majority of the studies were reporting data on free end saddles. Out of the 13 studies associated with bilateral free end saddle dentures, 9 studies showed a positive effect on masticatory efficiency. Various factors were found to have an impact on the masticatory performance (MP) of RPDs. Conclusion Subjective evaluation displays higher positive impact of RPDs in MP than objective evaluation. Assessment of patients' perspectives is important in clinical decision making. Multiple factors affect the MP with RPD treatment.

A technical and clinical digital approach to the altered cast technique with an intraoral scanner and polyvinyl siloxane impression material

This technique digitalizes the clinical and laboratory steps of fabricating removable partial dentures (RPDs) with the altered cast technique. An intraoral scanner was used to capture the mandibular Kennedy class II partially edentulous arch. An RPD framework was fabricated digitally and then combined with a custom tray with a wax occlusal rim. A conventional polyvinyl siloxane altered cast impression was made and then digitalized both intraorally and extraorally, followed by a digital interocclusal record. The resulting scan was modified to produce an additively manufactured cast. The teeth and gingival components were then designed and fabricated with a combination of additive and subtractive manufacturing, followed by the conventional acrylic resin pour technique. The definitive prosthesis was completed with minimal conventional techniques and without the use of gypsum, prefabricated teeth, or a physical articulator. The technique reduces the number of appointments and achieves the functional extension of the prosthesis through border molding, which is not possible with intraoral scanning.

"Just Engage in It or Not, You Get Out What You Put In": Student and Staff Experiences of Feedback and Feedforward in Workplace-Based Learning Environments

Feedback is central to student learning in the veterinary workplace. Feedforward, a related concept, is used to describe the way information about a student's performance may be used to improve their future performance. Feedback and feedforward practices are diverse, with varied student and staff understandings of the nature and purpose of feedback (feedback literacy). This study compared the practices of feedback and feedforward in a range of programs in one institution during student transitions from the classroom to workplace-based learning environments. The study adopted a broad inter-professional approach to include health care programs and social work and theater and performance studies. Profession-specific focus groups were conducted with contribution from 28 students and 31 staff from five different professions. Thematic analysis revealed that students and staff shared an understanding of the feedback and feedforward concepts, and both groups recognized the importance of emotional and relational aspects of the process. Students and staff across all professions recognized the impact of time constraints on the feedback process, although this was particularly highlighted in the health science professions. Social work and theater and performance studies students demonstrated a more nuanced understanding of the emotional and relational aspects of feedback and feedforward. Overall, the approach highlights similarities and differences in practices and experiences in different workplace contexts, creating opportunities for cross-disciplinary learning, which may have relevance more widely in higher education programs with workplace-based elements. The study underpinned the development of the LeapForward feedback training resource (https://bilt.online/the-leapforward-project/).

Survival of Single-Unit Porcelain-Fused-to-Metal (PFM) and Metal Crowns Placed by Students at an Australian University Dental Clinic over a Five-Year Period

The aim of this retrospective study was to determine the survival rate of single-unit porcelain-fused-to-metal (PFM) and metal crowns placed by dental students at an Australian university undergraduate dental clinic over a five-year period. Complications and the incidences of crown failures were recorded. Clinical records pertaining to single-unit PFM and metal crowns inserted over a five-year period were reviewed, including patient-related, tooth-related, and procedural factors for each crown. Crowns were evaluated as surviving, surviving with complications, or failed. Kaplan–Meier statistical analysis was used to estimate survival rate., This study is based on a sample of 232 (78.4%) PFM crowns and 64 (21.6%) metal crowns inserted between 2014 and 2018. Cumulatively, 224 (75.7%) were surviving, 48 (16.2%) were surviving but previously had complications, and 24 (8.1%) failed. The 5-year cumulative survival rate of all PFM and metal crowns was 83.9% (0.839 ± 0.038, Kaplan–Meier). The average survival time for all crowns was 4.432 ± 0.089 years. Comparatively, PFM crowns had a higher survival rate at 1 year (0.972 ± 0.010) and 2 years (0.919 ± 0.017), compared to metal crowns at 1 year (0.964 ± 0.011) and 2 years (0.894± 0.018). The survival rate of metal crowns remained constant from 2 years to 4 years and thereafter, whereas there was a continued decline in the survival rate of PFM crowns to 83.2% (0.832 ± 0.038) at 4 years and thereafter. Crowns placed on premolars had the highest cumulative survival rate whereas those placed on molars exhibited the lowest survival rate for the duration of the study period. Despite single-unit PFM crowns having a higher 1- and 2-year survival rate compared to metal crowns, metal crowns had a higher survival rate at 4 years and thereafter. Survival rates are comparable to previous studies.

An investigation into the prevalence of combination syndrome

OBJECTIVES

To investigate the prevalence of Combination Syndrome, and to investigate if provision of a mandibular removable partial denture has any influence on the prevalence of Combination Syndrome.

METHOD

Patients attending Kings College London Dental Institute, Guys Hospital who wore maxillary conventional complete dentures opposing mandibular anterior teeth only, with or without mandibular partial dentures were examined by one examiner. Oral health, residual alveolar ridge and denture quality were assessed. Features putatively associated with Combination Syndrome were recorded. Patient ratings of dentures were recorded.

RESULTS

99 patients were recruited who were wearing maxillary removable complete dentures opposing only mandibular anterior teeth. Of these, 64 patients wore mandibular removable partial dentures and 35 patients did not. Only 8 patients displayed two features of Combination Syndrome and 38 patients displayed one feature of Combination Syndrome, excessive resorption of the anterior maxillary sextant. These findings are not compatible with previous research which suggested that the five features of Combination Syndrome were prevalent in patients wearing maxillary complete dentures opposing mandibular anterior teeth.

CONCLUSIONS

Evidence supporting the existence of Combination Syndrome was not discovered in this research. Prevalence of Combination Syndrome appeared to be low or non-existent. Patient treatment modalities and teaching in relation to Combination Syndrome may need to be modified.

Predoctoral teaching in intravenous conscious sedation: ten years at Glasgow dental school

Supervised clinical practice in intravenous conscious sedation was introduced into the predoctoral dental curriculum at Glasgow Dental School and Hospital, United Kingdom, with the appointment of two full-time academic staff members in 2001. This article reviews the student experience gained in the succeeding ten years. All students administered intravenous sedation to patients during the course as well as assisting with intravenous sedation provided by their peers. The experience was variable, mainly as a result of student and patient attendance. Adverse weather and increasing student numbers also affected student experience. This study demonstrated that it is possible to provide supervised clinical sedation practice for students as part of a predoctoral dental curriculum.

Comparison between two regional anaesthesia techniques performed by inexperienced operators: the Gow-Gates block versus the Kenneth Reed block

AIM

The aim was to compare the efficacy of Kenneth Reed and Gow-Gates inferior alveolar nerve blocks when performed by an inexperienced operator.

METHODS

A group of 60 patients was randomised into two groups. One group had the Kenneth Reed technique used to administer an inferior alveolar nerve block whilst the other received the Gow-Gates technique. The efficacy of nerve block produced was evaluated both clinically and by electric pulp tester. MRI examination was undertaken to determine the spread of local anaesthetic.

RESULTS

There were no significant differences in success rate of anaesthesia between groups. The failure rate for the Gow-Gates technique was 16.6%, whilst the failure rate for the Kenneth Reed technique was 23.3%. Time to onset was less with the Kenneth Reed technique. MRI examination showed the solution was more widely distributed after the Kenneth Reed block had been used.

CONCLUSIONS

Our research has demonstrated that the Kenneth Reed technique is equally effective at producing anaesthesia of the inferior alveolar nerve. Compared with conventional techniques there is a lower incidence of positive aspiration and potential for lower morbidity as the local anaesthetic is deposited further from the neurovascular bundle than when deposited near the mandibular foramen as in most conventional Inferior Alveolar Nerve Block techniques.

Intravenous conscious sedation in children for outpatient dentistry

The use of general anaesthesia for dental treatment in the NHS outside hospitals has changed over time. Although deaths are uncommon during or immediately after general anaesthesia for dental treatment, they are more likely to occur than with other methods of pain and anxiety reduction, such as local anaesthesia and conscious sedation. Inquiries into recent anaesthetic deaths in dental practice have been critical of the standard of care provided in areas such as pre-operative assessment, monitoring, resuscitation and transfer to specialist critical care facilities.

Which is the most effective drug or method of sedation used for anxious children? What are the most effective techniques for the use of conscious sedation behaviour management in paediatric dentistry?

DATA SOURCES

Medline, PubMed, Embase, Cochrane Central Register of Controlled Trials, Dissertation Abstracts, SIGLE, the World Wide Web (Google) and the Community of Science Database were searched for relevant trials and references. Reference lists from relevant articles were scanned and the authors contacted to identify trials and obtain additional information. There were no language restrictions. Trials pre-1966 were not searched.

STUDY SELECTION

Studies were selected if they met the following criteria: randomised controlled trials of conscious sedation comparing two or more drugs/techniques/placebo undertaken by the dentist or one of the dental team in anxious children up to 16 years of age.

DATA EXTRACTION AND SYNTHESIS

Information regarding methods, participants, interventions and outcome measures and results was independently extracted, in duplicate, by two authors. Specialist advice was sought to categorise interventions. Authors of trials were contacted for details of randomisation and withdrawals and a quality assessment was carried out not using any formal scoring system. The Cochrane Oral Health Group statistical guidelines were followed.

RESULTS

Fifty-three studies were included with 2345 subjects in total. Overall quality of studies was found to be disappointing with poor reporting, often the main problem. Data reported could not easily be aggregated into groups to facilitate description of results. Meta-analysis of the available data was also not possible for the same reason. The variety of differing drug regimens compared made it difficult to isolate groups of studies that were sufficiently similar in design to allow sensible comparison. Where groups of studies could be isolated, the differing outcome measures used made their meta-analysis impossible.

CONCLUSIONS

Authors were not able to reach any definitive conclusion on which was the most effective drug or method of sedation used for anxious children. A list of proposed areas of study was described.

A partially blinded randomised controlled trial of patient-maintained propofol sedation and operator controlled midazolam sedation in third molar extractions

Patient-maintained sedation using propofol has recently been shown to be effective for dental surgery. We compared this new technique to the established technique of operator administered midazolam. The two groups were compared before, during and after sedation. The two primary outcomes were time until discharge and oxygen saturation. Vital signs, anxiety and psychomotor skills were also compared. State anxiety was reduced to a greater extent in the propofol group (mean difference 10 (SD 4) mm; p = 0.010. Propofol patients recovered quicker (mean difference 7 (SD 1.4) min; p = 0.001). Propofol patients had a smaller reduction in arterial oxygen saturation (mean difference 0.8 (SD 0.3)%; p = 0.030), and a reduced increase in heart rate (mean difference 9 (SD 2) beats.min(-1); p < 0.001). Both techniques were well tolerated and safe. Propofol sedation offered superior anxiolysis, quicker recovery, less amnesia and less depression of simple psychomotor function.

Intravenous conscious sedation in patients under 16 years of age. Fact or fiction?

Recently published guidelines on the use of conscious sedation in dentistry have published varying recommendations on the lower age limit for the use of intravenous conscious sedation. There are a large number of dentists currently providing dental treatment for paediatric patients under intravenous conscious sedation. The 18 cases reported here (age range 11-15 years), were successfully managed with intravenous conscious sedation. The experience in this paper is not sufficient evidence to recommend the wholesale use of intravenous conscious sedation in patients who are under 16 years. The fact that a range of operators can use these techniques on paediatric patients would suggest that further study should be carried out in this population. The guidance should be modified to say there is insufficient evidence to support the use of intravenous conscious sedation in children, rather than arbitrarily selecting a cut off point at age 16 years.

The prevalence, etiology and management of tooth wear in the United Kingdom

STATEMENT OF PROBLEM

Recent epidemiologic evidence suggests that tooth wear is now a significant problem in both children and adults. There is growing evidence that a major cause of severe wear in patients is regurgitation erosion due to a variety of factors including gastroesophageal reflux disease.

PURPOSE

The purpose of this article is to discuss the prevalence of tooth wear in the United Kingdom. Emphasis in management should be on accurate diagnosis, and in some patients, long-term monitoring before embarking on any irreversible, interventive treatment. Even when treatment is necessary, a period of monitoring is helpful to assess the rate of progress of the wear, the effectiveness of preventive measures, and therefore the extent of the treatment necessary.

Sedation in practice. 4: The use of sedation for the medically compromised patient

This, the fourth paper in a series of uses of sedation in general dental practice, reviews the use of sedative techniques for patients who have medical conditions which will affect their ability to co-operate with dental treatment or which may be aggravated by the stress of treatment. Advice is given on a range of other conditions which may present as incidental findings when the patient's medical history is being taken.

Postgraduate education in sedation--a new development

Although demand for sedation courses has continued to increase, the traditionally theoretical format has tended to leave participants without the necessary clinical skills to practice sedation techniques with confidence. This article describes a new model of sedation course, introduced at Newcastle Dental Hospital and School, which has managed to overcome this problem.

Sedation in dental practice. 3: The role of sedation in the management of problems with local anaesthesia

This article describes how sedation can help to overcome some of the problems associated with the use of local anaesthesia for dentistry. It also reviews those problems where sedation is not the appropriate choice, and gives guidance on distinguishing the appropriate from the inappropriate, along with suggestions for how such cases might be managed.

Epileptic fits under intravenous midazolam sedation

A case is presented of a patient who suffered from recurrent epileptic fits while being treated under intravenous sedation with midazolam. Those using sedation are advised to beware of the patient who gives a history of fits being provoked in the dental environment.

Sedation in dentistry. Part 2: Management of the gagging patient

Sedation should be considered as a useful part of the general dental practitioner's armamentarium and as an important alternative to general anaesthesia in selected cases. In this, one of a series of articles on the uses of sedation in various circumstances, the management of the gagging patient is discussed. The many factors involved in the aetiology of the hyperactive gag response are reviewed and measures for dealing with it suggested.

Sedation in dentistry. Part 1: assessment of patients

This is the first in a series of articles on the uses of sedation in general dental practice. This paper reviews current recommendations for the practice of sedation, and the importance of patient assessment as a part of treatment. The dental and psychosocial indications, as well as medical contraindications, for sedation are discussed. Future articles will expand on other areas where sedation may be a useful tool in the general dental practitioner's armamentarium. It is hoped that these articles will encourage all practitioners to consider a wider use of sedative techniques in dentistry.

The prevalence of toothwear in 1007 dental patients

The dental profession is becoming increasingly concerned about unacceptable levels of toothwear and there is an impression that the condition is becoming more prevalent. There is, as yet, little epidemiological evidence to illuminate the question and so this study is therefore intended to provide baseline data on the prevalence of toothwear in a sample of the dental attending population of South East England. A degree of toothwear is normal and progresses throughout life. Toothwear which is acceptable in an older age group would not be so with younger patients. It is therefore necessary to designate threshold values of acceptable levels of toothwear for different age groups to reach realistic conclusions about the prevalence of unacceptable levels of toothwear. Of the 1007 patients examined only nine had completely unworn dentitions. More than 93,500 tooth surfaces were examined and of these 5.1% had wear which exceeded the threshold values. Despite increasing the threshold values for the older age groups from those proposed in an earlier study by Smith & Knight (1984), these patients still had higher levels of unacceptable toothwear. There was a slight tendency for men to have more wear than women, but there was no clinically significant relationship between the number of missing posterior teeth and wear of the anterior teeth.

Anorexia and bulimia nervosa (the eating disorders): conditions of interest to the dental practitioner

OBJECTIVES

This paper aims to give the dental practitioner an insight into the impact of the eating disorders on sufferers.

METHODS

A review of the psychiatric literature on the diagnosis, aetiology and treatment of these conditions is given.

CONCLUSIONS

The dental practitioner is in an ideal position to identify the warning signs of these conditions before they have attracted medical attention.

Chronic alcoholism: an important condition in the dentist-patient relationship

OBJECTIVES

This paper aims to give the dental practitioner an insight into the impact of chronic alcoholism on sufferers.

METHODS

A review of the psychiatric and dental literature covering the aetiology, prevalence and complications is presented.

CONCLUSIONS

Chronic alcoholism has a number of serious medical and social problems which may affect the provision of dental treatment. It is important for the dental practitioner to be aware of the impact of this condition on patients as he or she may be in an ideal position to stop the alcoholic before a medical consultation has been sought.

The parallel stripes mystery

A series of artefacts seen on intra-oral radiographs are described. These have been shown to be caused by contamination from fixing solution on the clips used to hold the films during processing. Thorough cleaning of these clips between uses prevented recurrence of these artefacts.

The distribution of erosion in the dentitions of patients with eating disorders

Anorexia and bulimia nervosa (the eating disorders) are potentially life threatening and are becoming more prevalent. This paper reviews the effects of these disorders on dental erosion and reports a study to assess the effects of the eating disorders on the erosion of teeth relating the severity of erosion to factors such as the frequency of self-induced vomiting (SIV). One hundred and twenty-two eating disorder patients and an equal number of age, sex, and social class matched controls were studied. The study population was divided into subgroups according to the eating disorder. All the subgroups had significantly more abnormal toothwear than the controls (P < 0.005), with the differences being most marked in the SIV groups. Further analysis did not find any consistent relationships to the frequency or duration of SIV.

Regurgitation erosion as a possible cause of tooth wear in ancient British populations

Clinically, in modern populations, tooth wear can be differentiated into three main types--attrition, abrasion and erosion, acting either separately or together. Anthropologists generally have not recognized erosion as a factor affecting the teeth of past populations. This study compares the patterns of wear known to be associated with erosion in present-day dental patients with those found in some British, pre-Conquest, skeletons. It is concluded that erosion may have been a major factor causing the extensive tooth wear in some 20 of 151 individuals.

Prevalence of pathological tooth wear in patients with chronic alcoholism

Although chronic alcoholism is a very common condition, with potentially harmful consequences for the sufferer, there has been little emphasis in the literature on its effects on the teeth. This study of 37 alcoholic patients showed that their teeth had significantly more wear than age and sex matched controls. The tooth wear was most marked in males, and those whose alcohol consumption was continuous rather than in the form of episodic binges. The wear appeared to be erosive in nature, and in 40% of the sample it affected the palatal surfaces of the upper anterior teeth. It is therefore suggested that general dental practitioners should bear in mind the possibility of chronic alcoholism in cases of unexplained dental erosion.

Myelin basic protein: interaction with calmodulin and gangliosides

The structural characteristics of myelin basic protein (MBP) involved in protein-protein and protein-lipid interactions were investigated. Rabbit MBP could bind calmodulin (CaM) in the presence of Ca2+ to form a complex that remained undissociated in 8 M urea. However, no tight complex formation was observed when the divalent cation was absent. These results suggest that MBP may contain a hydrophobic domain similar to those in the other well-characterized CaM-binding proteins. The stoichiometry of calmodulin binding to MBP was approximately 1:1. Prior limited proteolysis of MBP with trypsin abolished the formation of the MBP-CaM complex, indicating that the entire MBP polypeptide may be involved in the recognition of the hydrophobic clefts in CaM. MBP also formed tight complexes with gangliosides, but the presence of Ca2+ was not required. Binding of gangliosides to MBP-CaM complex released CaM from the complex. The ganglioside-binding sites in MBP were determined after trisecting the protein at two glutamic acid residues with Staphylococcus aureus V8 protease. Subsequent binding studies revealed that a 9.5-kDa polypeptide, which may correspond to the NH2-terminal domain (residues 1-83) of MBP, had higher affinity for the binding of lucifer yellow CH-labeled GM1 than did the other two polypeptides, of apparent molecular mass (Mr) 5,500 and 4,500, respectively. Among the various proteins in purified guinea pig brain myelin, synaptosomes, and synaptosomal membranes, MBP was found to have the highest affinity in binding lucifer yellow CH-GM1.

Dental erosion in patients with chronic alcoholism

Tooth wear attributed to the physical wear of teeth by clenching and grinding (attrition) has been described previously in alcoholic patients. However, the pattern of wear seen in the series of cases reported here is more consistent with chemical damage (erosion) than attrition. A possible mechanism for this process is suggested, and it is further suggested that erosion is likely to play a more important role in the wear of the teeth in chronic alcoholic patients than attrition.