Rehabilitation of the worn dentition

Rehabilitation of a Patient With Maxillary Defect and Severe Attrition Using Obturator Prostheses: A Case Report

Surgery for palate lesions may result in oro-nasal/antral communication, which reduces a person's quality of life by affecting swallowing, speech, and food reflux. The shape and size of this obturator prosthesis might vary based on the severity of the defect. This case report describes the prosthetic rehabilitation of the patient with post-COVID mucormycosis and generalized attrition of teeth using an obturator and full mouth rehabilitation.

Do onlays and crowns offer similar outcomes to posterior teeth with mesial-occlusal-distal preparations? A systematic review

OBJECTIVE

Teeth prepared for mesial-occlusal-distal (MOD) restorations have a significant risk of cusp fracture. Crowns and onlays can provide cusp coverage to reinforce posterior teeth at risk. Onlays are often more conservative of tooth structure which may be an advantage for teeth with large MOD preparations. It remains uncertain how onlays and crowns compare for posterior teeth with MOD tooth structure loss. The purpose of this systematic review was to compare the resistance to fracture, success rate, survival rate, and failure rate of teeth with MOD preparations restored with onlays or crowns.

MATERIALS AND METHODS

An electronic search queried Medline (PubMed), Embase (Ovid), Scopus, the Cochrane Library, and grey literature (OpenGrey) from database inception through April 29, 2023.

RESULTS

After eliminating duplicates and irrelevant records, 32 manuscripts were assessed. Only three publications met the criteria for inclusion. Most exclusions were due to poor reporting of restorative design and the amount of tooth structure remaining, or due to combining various restorative designs. Due to the limited sample size and high heterogeneity, no meta-analysis was conducted. One study observed a better outcome for onlays and two observed no difference. All three studies reported the mode of failure for crowns as more catastrophic whereas teeth with onlays could be salvaged.

CONCLUSIONS

Onlays may be an advantageous alternative to crowns for teeth with MOD preparations, but the level of evidence is insufficient to draw meaningful conclusions.

CLINICAL SIGNIFICANCE

Current evidence is insufficient to determine whether onlays or crowns are providing a different outcome when used to restore posterior teeth with MOD tooth structure loss. However, the fracture of teeth with MOD tooth structure loss restored with onlays appears to be less catastrophic than when restored with crowns.

Chewing performance of patients with worn dentition before and after restorations: A scoping review

BACKGROUND

Tooth wear is a multifactorial complex process related to the loss of dental tissue, due to chemical or mechanical processes, by abrasion, attrition, erosion. Restorative treatment represents an attempt to rebuild and recreate the lost structure.

OBJECTIVE

This scoping review aims to investigate whether restorative treatment of worn dentition (either with direct or indirect adhesive composite adhesive procedures or with prosthetic techniques) can have an impact on the masticatory performance parameters.

METHODS

A scoping review was conducted on multiple databases (Pubmed, Medline CENTRAL, ICTRP), following the PRISMA guidelines. Abstracts of research papers were screened for suitability, and full-text articles were obtained for those who satisfied the inclusion and exclusion criteria.

RESULTS

Only one article meet the inclusion criteria of the review. Restorative treatment of worn dentition although have a positive impact on the self-report ability to chew, has no effect on the masticatory performance test.

CONCLUSION

At the moment, not enough evidence to comment on the actual therapeutic role of restorative treatment on tooth wear is available. Clinicians, before taking any clinical decision, should carefully discuss with patients the needs and expectations of the treatment plan.

Effect of different ceramic systems on antagonist dental structure by microtomographic analysis

OBJECTIVES

This study aims to identify the two-dimensional and three-dimensional analyses and evaluate the loss of tooth structure in the tooth's different constituent elements and the ceramic antagonist's surface.

METHODS

In this study, three groups (n = 10) represented by different ceramic systems (lithium disilicate [GDis], lithium silicate reinforced with zirconia [GSil], and monolithic zirconia [GZir]) were evaluated. Each group obtained ten ceramic blocks and submitted them to the sintering/crystallization process. To carry out the wear test, healthy mandibular premolars were used as the specimens and the ceramic blocks as antagonists. The premolars were submitted to two-dimensional and three-dimensional analyses using a computerized microtomography (µTC) before and after the wear test. The wear test was performed with 30 N and 300,000 cycles load, with occlusion, laterality, and disocclusion movements.

RESULTS

The statistical analysis comparing the loss of two-dimensional tooth structure showed a statistically significant difference among all groups (p < 0.05). Statistical analysis comparing the percentage of loss of three-dimensional tooth structure showed a statistically significant difference between groups GDis and GSil and between groups GDis and GZir. However, when comparing GSil with GZir, no statistically significant difference was found. The qualitative analysis of the teeth showed that GDis showed considerable enamel loss and dentin exposure, GSil showed enamel wear with flattening the cusp without dentin exposure, and GZir showed minimal enamel wear without dentin exposure. In the qualitative analysis of ceramic antagonists, more significant wear of the ceramic material for GDis was observed, followed by the GSil and GZir groups, respectively.

SIGNIFICANCE

The use of the lithium disilicate should be cautious, restricting it to areas with lower masticatory forces. Areas of higher masticatory forces showed a large amount of antagonist wear, with dentin involvement. This can lead to dentinal hypersensitivity, risk of compromising patients' occlusion, by harming group disocclusion guides, causing pain and temporomandibular disorders.

Dental Implant Treatment in Bruxers: A Case Report and Literature Review

This case report presents a literature review and a case report of a full-mouth implant rehabilitation for a 65-year-old woman with a history of Bruxism. The patient's oral condition showed dentition with severe occlusal wear, extensive dental work, and missing teeth replaced with bridges and implants. The existing dental work was failing due to recurrent caries and the mechanical failure of long-span bridges. The unique aspect of the treatment presented in this report is the management of existing osseointegrated implants of different systems with different platform designs, which adds to the treatment's complexity. The existing implants were incorporated into the planned treatment, and other implants were added to support maxillary zirconia and mandibular hybrid full-arch prostheses. After 2 years of function, extensive wear was evident on the milled acrylic, even though an occlusal guard was used. New acrylic teeth were processed using the same milled titanium bar of the mandibular hybrid prosthesis, and the occlusal surfaces of the acrylic teeth were protected with gold onlays. The patient is seen regularly for maintenance every 6 months with no further complications. Careful evaluation, planning, and treatment execution are paramount in managing patients with a history of bruxism. Patients should be prepared and informed about possible mechanical failure and seen regularly for maintenance.

Trueness of 4 sectional-cast digital methods for transferring the interocclusal relationship in complete mouth rehabilitation

STATEMENT OF PROBLEM

An accurate digital workflow for transferring the interocclusal relationship from complete arch diagnostic interim restorations to complete arch tooth preparations is essential in complete mouth rehabilitation. However, research on the accuracy of digital cross-mounting methods is lacking.

PURPOSE

The purpose of this in vitro study was to compare the trueness of 4 sectional-cast digital cross-mounting methods in transferring the interocclusal relationship for complete mouth rehabilitation.

MATERIAL AND METHODS

Maxillary and mandibular anatomic typodonts were used to build complete arch tooth preparations and diagnostic interim restorations for complete mouth rehabilitation in vitro. Four sectional casts were designed: an anterior cast (AR), a posterior cast (PO), a unilateral cast (UL), and a tripod cast (TR). Both extraoral scanning (EOS) and intraoral scanning (IOS) were used to obtain intermediate digital sectional casts, which were cross-registered with diagnostic interim restorations and definitive casts to transfer the interocclusal relationship. Trueness was determined by assessing tooth distance deviation and mandibular 3-dimensional (3D) deviation. Differences among the 4 sectional-cast methods were analyzed with the Kruskal-Wallis test, and differences between the 2 scanning methods were analyzed with the Mann-Whitney U test (α=.05).

RESULTS

Significant differences in the trueness of interocclusal relationship transfer were observed among the 4 sectional-cast methods (P<.05). Regarding tooth overall distance deviation, TR-EOS found no statistically significant difference compared with PO-EOS (P>.05), but TR-EOS had half the overall distance deviation of PO-EOS. Both TR-EOS and PO-EOS had smaller deviations than the AR-EOS and UL-EOS groups (P<.05). TR-IOS had a smaller distance deviation than the AR-IOS, PO-IOS, and UL-IOS groups (P<.05). The overall distance deviation of EOS was significantly smaller than that of IOS in the TR and PO groups (P<.05). Regarding mandibular 3D deviation, TR-EOS found no statistically significant difference but had half the root mean square (RMS) of 3D deviation compared with the PO-EOS groups (P>.05). Both TR-EOS and PO-EOS groups had a smaller RMS than the AR-EOS and groups (P<.05). The TR-IOS group had a smaller RMS than the AR-IOS, PO-IOS, and UL-IOS groups (P<.05). The 3D deviation of EOS was significantly smaller than that of IOS in the PO group (P<.05).

CONCLUSIONS

Both EOS and IOS with the tripod sectional-cast digital method accurately transferred the interocclusal relationship for complete mouth rehabilitation.

Temporomandibular Disorders and Dental Occlusion: What Do We Know so Far?

Throughout the recorded history in the literature of temporomandibular disorders (TMD) there have been a variety of opinions as to its primary cause. Those supporting an occlusal basis of TMD opined that occlusal dysfunction is either the primary cause for or a significant etiopathogenic factor in the causation of TMD. Most of the current literature, however, points to evidence in another direction and questions the causal role of occlusion and occlusal disharmony in TMD etiopathogenesis. Recognition of this evidence-based literature is paramount in eliminating and preventing the chances of overtreatment of patients with TMD.

Interdisciplinary management of an adult patient with significant tooth wear

Adult patients may present with compromised dentitions which require extensive oral rehabilitation. This case report shows the fulfilment of both functional and aesthetic treatment objectives for a patient with significant tooth wear through carefully planned interdisciplinary management. © 2022 Australian Dental Association.

Safe and Ultraconservative Rehabilitation of Worn Teeth Patients: How Sectional Clear Aligners May Enhance the Prosthetic Treatment Plan

This study describes the clinical workflow for occlusal vertical dimension (OVD) increase in patients showing extensive tooth wear and mild teeth misalignment/crowding. A patient affected by dental erosion and occlusal abnormalities was treated to improve her situation. After ascertaining sound condyle and temporomandibular joint (TMJ) conditions, an OVD increase was sought to provide enough inter-occlusal space for the restorations. The use of TMJ three-dimensional imaging throughout the clinical procedures allowed to objectively track the condyle and disk position and confirm a steady condyle–glenoid cavity relationship before definitive restorations placement. Sectional clear aligner therapy prior to totally additive prosthetic rehabilitation allowed obtaining slight derotation and movements of anterior teeth, thus maximizing sound tissue preservation. Adhesively luted restorations were finally delivered on both anterior and posterior sectors. At the end of the treatment, the pre-operative TMJ balance appeared successfully preserved, and the patient was satisfied with the aesthetic and function achieved.

Prosthodontic Treatment in Patients with Temporomandibular Disorders and Orofacial Pain and/or Bruxism: A Review of the Literature

Temporomandibular disorders are a group of conditions affecting the temporomandibular joints, the jaw muscles, and related structures. Patients with temporomandibular signs and/or symptoms frequently present with indications for prosthetic treatment. The management of these patients aims to achieve patient comfort, occlusal stability, and the complex restoration of the teeth. The goal of this review is to provide an overview of the relationship between prosthodontics and temporomandibular disorders and/or bruxism with a focus on the cause-and-effect implications and the strategies for planning prosthetic treatments in patients with temporomandibular disorders and/or bruxism.

Evaluation by 3D stereophotogrammetry of facial changes in edentulous patients after rehabilitation

OBJECTIVE

To assess facial changes after oral rehabilitation with complete dentures (CDs) by 3D technology allows understanding the results of a treatment that changes facial proportions. Precise outcome parameters can improve decision making. This descriptive observational research aimed to assess facial changes in completely edentulous patients after oral rehabilitation with a CD by a 3D stereophotogrammetry system.

METHODOLOGY

30 edentulous patients (7 men and 23 women), aged 50 to 75, were analyzed with stereophotogrammetry at 28 previously determined anthropometric landmarks, at 2 different times: T1, before treatment, and T2, after inserting the CDs. Images were analyzed with a specific software for linear and angular measurements. The paired t-test was used to compare timestamps (α=0.05).

RESULTS

Major changes were observed in 7 of the 13 linear measures and 7 of the 9 angular measures. The following linear measurements had an increase: Sn-Gn (lower third of the face), Ls-Li (height of the vermilion lip), and ChL-ChR (mouth width). Sn-Ls (nasal philtrum height) decreased. For angular measurements, Sn-St-Pg (lower facial convexity) angles increased, and the Prn-Sn-Ls (nasolabial angle) and GoR-Pg-GoL (mandible convexity) angles decreased.

CONCLUSIONS

Major facial changes in newly rehabilitated edentulous patients with CDs included an increase of the lower third of the face, of the vermilion lip, of mouth width, and of the lower facial convexity, and a decrease of the nasolabial angle and mandible convexity.

Safe clinical technique for increasing the occlusal vertical dimension in case of erosive wear and missing teeth

A safe method to increase the occlusal vertical dimension (OVD) in patients with mild temporomandibular symptoms (such as tenderness upon palpation) is described. After a temporomandibular joint magnetic resonance (MR), an OVD increase was sought, pursuing pure rotational movement without condyle displacement. Prior to definitive rehabilitation, an additional MR confirmed steady and healthy condyle-disc-fossa relationships.

Adhesive Management of Anterior Tooth Wear in Combination with the Dahl Concept-A 27-Month Observational Case Series

Localized anterior maxillary tooth wear caused by erosion and attrition with loss of interocclusal space is difficult to manage. This observational case-series study reports six cases with worn anterior dentition treated with labial ceramic and palatal direct resin composite veneers at an increased vertical dimension of occlusion without restoration of unaffected posterior teeth. Thirty-six palatal direct veneers were made in six patients from a nanohybrid resin composite with the help of a wax-up-based template at an increased vertical dimension. After the complete re-establishment of posterior occlusion, 40 labial lithium-disilicate ceramic veneers were fabricated with a mock-up-guided method. The sandwich veneers were evaluated according to the United States Public Health Service (USPHS) criteria after a mean service time of 22.7 months. Re-establishment of posterior contacts as well as subjective patient satisfaction and function were evaluated. The overall success of the labial ceramic veneers was excellent. The quality of the palatal resin composite restorations was found to be good with predominantly "Alpha" scores. The marginal quality (11.1% and 33.3% of integrity and discoloration, respectively) and surface roughness (16.7%) showed small deteriorations indicated by "Beta" scores. The resin composite showed, in general, signs of wear facets which resulted in "Beta" scores in 44.4% of the cases. Posterior contacts re-established firmly within 4 weeks in all cases. Patient satisfaction with esthetics and function was high. The short-term outcome of this non-invasive treatment option is favorable and promising.

Occlusal problems, mental health issues and non-carious cervical lesions

Non-carious cervical lesions (NCCLs) are characterized by a loss of hard dental tissue near the cement-enamel junction with multifactorial etiology. The aim of this study was to demonstrate that occlusal factors as attrition, malocclusion, and bruxism, and mental disorders as depression, stress, and anxiety are involved in the etiology of NCCLs. Salivary samples and clinical data of 340 individuals selected from 6,112 participants were obtained from the University of Pittsburgh School of Dental Medicine Dental Registry and DNA Repository project. The affected group was formed by individuals with NCCL (34 females, 34 males, mean age 55.34 years). In addition, the comparison group was formed by individuals without NCCL (136 females, 136 males, mean age 55.14 years). Eleven single-nucleotide polymorphisms (SNPs) previously associated with mental disorders were genotyped and tested for association with NCCLs. When all occlusal factors were combined there was found a significant association with NCCL (p = 0.000001/adjusted OR 4.38, 95% CI 2.50-7.69). Attrition (OR 3.56, 95% CI 2.00-6.32) and malocclusion (OR 5.09, 95% CI 1.65-15.68) as separate variables showed statistically significant associations with NCCL. There was a significant difference in stress history between the two groups (OR 2.17, 95% CI 1.08-4.39). No associations between NCCLs and the SNPs selected were found. However, when the occlusal factors were analyzed as covariates, associations were found between bruxism and seven of the selected SNPs. Our results suggest that occlusal factors might be associated with NCCLs.

Reliability of qualitative occlusal tooth wear evaluation using an intraoral scanner: A pilot study

Dental wear analysis through the use of an intraoral scanner is a reality of modern dentistry. This study aimed to investigate the reliability of qualitative tooth wear evaluation through three-dimensional images captured with an intraoral scanner and compared to clinical and photographic examinations. Eighteen adult volunteers of both genders (18 to 55 years old) were submitted to clinical exams, intraoral photographs and intraoral scanning protocol using an optical scanner (TRIOS® Pod, 3Shape, Copenhagen, Denmark). Occlusal tooth wear, from second to second premolars, was measured by two evaluators and reevaluated after 30 days, according to a slight modification of the method described by Mockers et al. Weighted Kappa was used to measure intra and inter-examiner agreement. The Friedman test was used to verify the differences among methods. Random and systematic errors were assessed using Bland-Altman plots. All statistical analysis was performed with p<0.05. There was a substantive agreement for clinical (K = 0.75) and photographic exams (K = 0.79) and a moderate agreement for intraoral scanner analysis (K = 0.60) for inter-examiner evaluation. A substantial intra-examiner agreement was obtained for both evaluators. No significant difference between the methods was observed (p = 0.7343 for examiner 1 and 0.8007 for examiner 2). The Bland-Altman plot confirmed no systematic errors between the methods and a random error of 0.25 with the scanner method when compared to clinical assessment. All three methods showed reliability in qualitative occlusal tooth wear evaluation. Intraoral scanning seems to be a sound and reliable tool to evaluate tooth wear when compared to traditional methods, considering the lower inter-examiner agreement and the inherent limitations of this pilot study. Further research will be necessary in order to achieve more robust evidence.

Restoration of the dentition in a patient with a history of bruxism and amelogenesis imperfecta: A clinical report

The report describes a 27-year-old female patient with amelogenesis imperfecta (AI) accompanied by nocturnal bruxism, who was treated with a combination of occlusal splint and full-mouth fixed prosthetic rehabilitation through follow-ups within 2 years. Soft splint protection, regular follow-up, and monitoring of carries are guaranteed to maintain a long-term curative effect.

Rehabilitating simulated worn dentition by using a complete digital workflow and five anatomic guidelines

This report describes the rehabilitation of worn dentition by using a complete digital workflow on a nonhinged simulated patient. A dentiform was used to represent an individual with loss of occlusal vertical dimension. Interim restorations were designed following the simulated patient's midline, interpupillary line, and ala-tragus line and a defined central incisal edge position, posterior maxillary teeth central groove, and buccal cusp position of posterior maxillary teeth. The definitive restorations were then designed and fabricated by following the contour of the interim restorations.

Long-term results of a randomized clinical trial of 2 types of ceramic crowns in participants with extensive tooth wear

STATEMENT OF PROBLEM

Evidence is sparse regarding the long-term outcomes of restorative treatment of patients with extensive tooth wear.

PURPOSE

The purpose of this long-term prospective randomized clinical trial was to evaluate the performance and success rate of pressed lithium disilicate (LD) and translucent zirconia (TZ) crowns in participants with extensive tooth wear.

MATERIAL AND METHODS

A total of 62 participants with extensive tooth wear (17 women, 45 men; mean age 44.8 years; range 25-63 years) received a total of 713 crowns, LD=362 and TZ=351. Both types of crowns had chamfer preparations and were adhesively luted with dual-polymerizing composite resin cement (PANAVIA F 2.0; Kuraray Noritake Dental Inc). The restorations were clinically reevaluated on average 14, 31, 39, 54, and 65 months after insertion of the crowns according to the modified United States Public Health Service (USPHS) criteria.

RESULTS

After an observation period of up to 6 years, the survival rate for both types of crowns was 99.7%, with 1 lost LD crown after 1 year as a result of loss of retention and 1 lost TZ crown after 3 years because of tooth fracture at the cemento-enamel junction. The success rates were similar for both types of crowns: 98.6% for LD and 99.1% for TZ. Reasons for failures were that 3 participants in each group developed apical lesions, minimal ceramic fractures, or their crowns were rebonded after loss of adhesion. Assessment of color at baseline was significantly different with a better match for LD (84.8% Alfa, 15.2% Bravo) than for TZ crowns (36.5% Alfa, 63.5% Bravo), including TZ crowns with veneered porcelain (P<.001). Secondary caries and cracks did not occur. A post hoc analysis of clinical performance did not indicate any significant differences between extensive tooth wear with primarily mechanical or chemical factors.

CONCLUSIONS

No differences were found between the 2 types of ceramic materials concerning the long-term success and clinical performance, except that TZ crowns were rated by a blinded clinician as less esthetic than LD crowns. The use of high-strength ceramic materials, as well as reliable adhesive bonding, are probably the key factors in the long-term success of ceramic crowns in participants with extensive tooth wear independent of the specific etiology.

Replica-based inspection of enamel wear microfeatures

BACKGROUND

Surface replication is a nondestructive evaluation technique applied in examining surface wear by recording surface irregularities, especially in conditions when surfaces of interest cannot be further manipulated to fit directly under a microscope to be examined. Enamel is the outermost protective layer of the human teeth and is constantly stressed by mastication forces which results in enamel wear.

OBJECTIVE

To date, a procedure combining the clinical and microscopic examination of enamel surfaces is absent, which hinders the early diagnosis and comprehension of the wear process.

METHODS

This study investigated the role of replication sheets in registering microscopic wear on human enamel surfaces by both negative and positive replication techniques.

RESULTS

The sheets replicated wear features successfully. Sheets were compatible to use with multiple microscopes, with proper preparation, including high resolution microscopes such as the scanning electron microscope and transmitting electron microscope.

Correlations between dental wear and oral cavity characteristics: Mandibular torus, palatine torus, and oral exostoses

OBJECTIVE

This study evaluates the correlations amongst mandibular torus, palatine torus, oral exostoses to dental wear/loss and temporomandibular damage.

METHODS

The sample consists of 504 skulls from the Hamann-Todd Osteological Collection; 223 African American and 281 European Americans aged between 30 and 80 years. The sample was analyzed using Pearson's Chi-square for significance of sex, age, ancestry, and wear as well as the interactions between the demographic variables and the presence of mandibular torus, palatine torus and oral exostoses.

RESULTS

Wear was statistically significant by age and sex but not ancestry. The maxillary exostoses varied significantly by age, ancestry and wear but not sex. Mandibular torus frequencies varied significantly by wear, sex and ancestry. The palatine torus varied significantly across wear groups, sex and ancestry.

DISCUSSION

The etiology of nonmetric oral cavity characteristics, mandibular torus, palatine torus and oral exostosis, is complex. The degree to which traits' presence and expression is the result of genetic and environmental interactions is not fully understood. More than age, sex or ancestry, the degree of dental wear and tooth loss influences the presence and expression of the oral cavity traits. The sample can be characterized as the presence of exostoses in higher frequencies in young African American males with little tooth loss. Males of both ancestral groups with heavy wear have higher frequencies of mandibular tori than females. The palatine torus is more common in edentulous European American females.

Botulinum toxin type A for controlling bruxism assessed with computerized occlusal analysis: A pilot study

Objective: To assess botulinum toxin-A (BTX-A) on mandibular movements and bite force (BF%) in bruxism.Methods: Ten bruxers were divided into 2 groups based on BF% imbalance (G1: >10%, G2: <10%). BTX-A 140U was total injected into the masseter and temporalis muscles. A T-Scan® recorded BF%, occlusion time (OT), right, left, and protrusive disclusion time (DT) before administering BTX-A, as well as 15, 45, 90, and 120 days after injection.Results: The Friedman and Wilcoxon tests found significant differences in BF% in G1 subjects at 15 days (p = 0.028 s), OT at 90 (p = 0.043 s), and 120 (p = 0.027 s) days, DTR at 90 (p = 0.046 s) and 120 (p = 0.028 s) days, DTL at 15 (p = 0.043 s) and 90 (p = 0.027 s) days, and DTP 45_-90 days (p = 0.043 s).Conclusion: BTX-A induced BF% starting at 15 days post-injection and influenced lateralities later.

The effect of botulinum toxin injections on bruxism: A systematic review

OBJECTIVE

To systematize evidence on the efficacy of botulinum toxin type A (BTA) in the treatment of bruxism measured through bite force or electromyography (EMG) at the masseter muscle.

METHOD

Identification of relevant articles through databases PubMed, Web of Science, SCOPUS, Ovid and EBSCO and manual search were performed for sources from review articles. Studies scoring less than 3 on the Jadad Scale were excluded.

RESULTS

Four articles were included after an exclusion of 333 articles. 3 articles measured EMG and 1 bite force. 1 article did not record a significant drop of activity, 1 article recorded reduction midway and at final endpoint. 2 articles recorded initial reduction, but a non significant difference at later follow up.

CONCLUSION

The available research is inconclusive and does not show enough evidence that bruxism can be treated with BTA injections. However, promising results have been shown in individual studies and further research in this area is needed.

Tooth wear in Swedish adults-A cross-sectional study

BACKGROUND

Tooth wear has been recognised as a growing oral health problem in children and adolescents, with erosion often cited as the main cause of the tooth wear. Most studies on tooth wear have been conducted on children and adolescents, and only few studies focus on adults. Our aim was to study the prevalence of different types of tooth wear in an adult population and investigate related factors to tooth wear.

METHODS

A total of 831 adults in Sweden participated in the study by completing a questionnaire about oral health, a clinical examination, saliva sample and intraoral photographs. Tooth wear was estimated according to the Basic Erosive Wear Examination index, and the aetiology was determined based on the clinical appearance.

RESULTS

Almost 80% of the individuals had signs of erosion, and over 90% had signs of attrition. A high level of tooth wear was found in 4.6% of the individuals, few of who reported having received information about both attrition and erosion. Significantly, more men had tooth wear. Daily consumption of fruit had a stronger correlation to tooth wear than acidic drinks.

DISCUSSION & CONCLUSION

A high level of tooth wear was found in 4.6% of the individuals, and it was more common in men than women. Aside from attrition, tooth wear due to erosion was a frequent finding in adults. Only a few of the individuals with a high level of tooth wear reported to have received information about tooth wear from their dentist or dental hygienist.

Polysomnographic scoring of sleep bruxism events is accurate even in the absence of video recording but unreliable with EMG-only setups

PURPOSE

To determine the accuracy of scoring masticatory muscle activity (MMA) events in seven different polysomnography (PSG) setups.

METHODS

Nineteen volunteers (13 females, 6 males, age 31.1 ± 12.9 years, 12 self-proclaimed bruxers) attended one-night PSG recording, supplemented with audio, video, and a separate frontal electroencephalography electrode set (FES). The same examiner scored the MMA events with seven different setups, with varying number of channels available: (1) one, (2) two, and (3) four EMG channels, (4) PSG without audio or video (PSG-N), (5) home PSG with FES and audio (FES-A), (6) PSG with audio (PSG-A), and (7) PSG with audio and video (PSG-AV). A subset (n = 10) of recordings was scored twice to determine intra-scorer reliability. MMA indices and accuracy of scoring the events in different setups were compared against PSG-AV.

RESULTS

The intra-class correlation coefficient (ICC) between PSG-AV and PSG-A was high (0.940, p < 0.001) as well as for FES-A (0.927, p < 0.001), whereas for PSG-N, it was lower (0.835, p < 0.001); for setups with only EMG channels, coefficients were very low (ICC < 0.100 for all). Intra-examiner reliability was high (ICC > 0.939 for all setups), with the exception of PSG-N (ICC = 0.764, p = 0.002). When comparing against the MMA events scored in PSG-AV, the sensitivity of MMA event recognition for PSG-A was 78.5% and specificity 95.5%, which were substantially higher than sensitivity (52.0%) and specificity (87.2%) of PSG-N.

CONCLUSIONS

MMA event scoring accuracy with PSG-A or FES-A is almost comparable to PSG-AV. Since precise event recognition is essential for accurate MMA scoring, it is evident that one cannot rely exclusively on EMG.

A craniometry-based predictive model to determine occlusal vertical dimension

STATEMENT OF PROBLEM

Craniometry is a method of determining the occlusal vertical dimension (OVD); the current prediction models do not consider factors such as facial type and sex or normalizing the OVD by using 1 main variable.

PURPOSE

The purpose of this clinical study was to determine whether sex, facial type, and age can influence the creation of a predictive model by using the right or left eye-to-ear distance to determine the OVD in dentate and edentate individuals.

MATERIAL AND METHODS

Healthy individuals (N=385) (238 women, 147 men) aged between 18 and 50 years were classified according to sex, age, and facial type. A single operator recorded all distances in millimeters between the anatomic landmarks proposed by Knebleman (nose-to-chin and right and left eye-to-ear distances) by using a computer numerical control (CNC) machined aluminum anatomic gauge. Measurements were converted into z-scores to determine abnormal values (±3 standard deviations criteria). The Pearson correlation coefficient was calculated for each facial type and for the entire sample between nose-to-chin and the right and left eye-to-ear distances. Multiple regression analysis was performed to establish the dependence of the measured variables on the OVD and the development of a further predictive model (α=.05).

RESULTS

According to the z-scores of the measured distances, 4 participants were discarded, leaving a final sample of 381 participants (237 women, 144 men; 115 leptoprosopic, 164 mesoprosopic, 102 euryprosopic). The left eye-to-ear distance showed a better correlation with the nose-to-chin distance (leptoprosopic r=0.54, mesoprosopic r=0.60, euryprosopic r=0.55, total sample=0.56) than the right eye-to-ear distance (leptoprosopic r=0.48, mesoprosopic r=0.56, euryprosopic r=0.54, total sample=0.51). Multiple regression analysis revealed that age was not a predictive variable (P=.57), that OVD depended on sex (P<.001) and facial type (P<.01), and that women had shorter OVD than men, as well as more euryprosopic faces than leptoprosopic faces. Using these relationships, the following equation to determine OVD was constructed as a model: OVD=42.17+(0.46×left eye-to-ear distance)+sex (women=-3.38, men=0)+facial type (leptoprosopic=0, mesoprosopic=-1.19, euryprosopic=-2.19).

CONCLUSIONS

OVD depends on facial type and sex, both of which are craniometric variables. This study proposed a baseline method of determining OVD by using the left eye-to-ear distance as an initial reference that involves a straightforward mathematical calculation.

Fatigue resistance of ultrathin CAD/CAM ceramic and nanoceramic composite occlusal veneers

OBJECTIVE

The fracture resistance of different ultrathin occlusal computer-aided design/computer-aided manufacturing (CAD/CAM) veneers was investigated under cyclic mechanical loading to restore combined enamel-dentin defects.

METHODS

Eighty-four molars were reduced occlusally until extensive dentin exposure occurred with a remaining enamel ring. Twenty-four molars were ground flat for examination of highly standardized specimens, of which 8 were treated with uniformly flat 0.3mm IPS Empress CAD and 0.3 and 0.5mm IPS e.max CAD restorations. Sixty-four molars were anatomically prepared until dentin exposure and were restored using occlusal veneers with fissure/cusp thicknesses of 0.3/0.5mm from 3 different dental CAD/CAM materials: IPS Empress CAD, IPS e.max CAD and Lava Ultimate CAD/CAM. Teeth were etched with 37% phosphoric acid, and occlusal veneers were bonded using an adhesive luting system (Syntac Primer, Adhesive, Heliobond and Variolink II). Specimens were placed under cyclic mechanical loading in a chewing simulator (1 million cycles at 50N) and were examined for cracks after each cyclic loading sequence. The anatomical 0.3/0.5mm IPS e.max CAD specimens experienced an additional 1 million cycles at 100N. Kaplan-Meier survival curves and log-rank tests were used for data analysis.

RESULTS

All highly standardized and 0.3/0.5mm IPS e.max CAD specimens tolerated cyclic loading. One anatomical Lava Ultimate CAD/CAM and 10 IPS Empress CAD specimens showed cracks.

SIGNIFICANCE

Ultrathin occlusal veneers of lithium disilicate ceramic and nanoceramic composite showed remarkably high fracture strength under cyclic mechanical loading. These veneers might be a tooth substance preserving option for restoring combined dentin-enamel defects.

Evaluation of vertical facial height reduction and severity of temporomandibular joint disorders using Shimbashi number and cephalometric analysis

Objective: This study was designed to evaluate the correlation between vertical dimension at occlusion (VDO) and various grades of temporomandibular disorders (TMDs) versus controls.Methods: Clinically measured Shimbashi number and radiographic cemento-enamel junction (CEJ-CEJ) measurements on 120 TMD patients and 40 controls were evaluated. Radiographic lateral cephalometric skull images of the patients were subjected to cephalometric analysis. The relationship between Shimbashi number, the cephalometric values, and its correlation with the degree of TMD were evaluated and statistically analyzed.Results: Shimbashi number and radiographic CEJ-CEJ values in the TMD patients were significantly lower than those in the controls. TMD severity appeared to increase with the increase in interincisal angle and the decrease in both Shimbashi number and radiographic CEJ-CEJ value.Conclusion: These findings indicate that radiographic evaluation of cephalograms is a reliable indicator of presence and degree of TMD, and the severity of TMD increases with the degree of reduction in VDO.

Clinical presentation of two phenotypes of tooth wear patients

OBJECTIVE

To assess the clinical presentation of wear lesions in two phenotypes of tooth wear (TW) patients based on distribution and morphological features of wear.

MATERIALS AND METHODS

103 patients (mean age = 43.1 years) were divided into two groups based on cluster analysis; cluster A (61 patients) and cluster B (42 patients). The distribution of wear lesions, scores of presence or absence of 10 defined morphological TW criteria and number of teeth fulfilling each criteria were compared between groups. Intra- and inter-examiner reliability of the 10 TW criteria was determined by Cohen's kappa and intraclass correlation coefficient.

RESULTS

While cluster A had more wear in maxillary anterior teeth and mandibular molars compared with the same opposing tooth groups (p < 0.001, p < 0.007 respectively), there were no differences for cluster B. Cluster A was characterized by higher prevalence of 4 chemical morphological criteria and the highest number of teeth affected by one chemical criteria, whereas cluster B had a higher prevalence of one mechanical criteria and higher number of teeth affected by an additional mechanical criteria. Both intra- and inter-examiner values for the defined TW criteria were fair to excellent.

CONCLUSION

The results may indicate a more chemical background for TW in cluster A and mechanical background in cluster B. Furthermore, clinicians may use certain clinical features of TW to distinguish between individuals who belong to a specific TW cluster with a presumed chemical or mechanical etiology. These preliminary findings need to be confirmed in future studies.

Effect of zirconia polycrystal and stainless steel on the wear of resin composites, dentin and enamel

This study evaluated the effect of two antagonist substrates (Y-TZP/zirconia or stainless steel) on the wear rate and surface alterations of different composite materials and bovine tooth substrates (enamel and dentin). The wear rate of different composite materials (n = 20; two direct composite resins: HelioMolar - HM; Clearfil AP-X - CAP, three indirect composite resins: Estenia C&B - EST; Adoro - ADO; Sinfony - SFY, and one composite resin for direct/indirect restorations: Filtek Z250 - Z250), bovine enamel and dentin against two different antagonist materials (zirconia or stainless steel) into two mediums (two-body and three-body wear) were collected. After wear tests on ACTA wear machine, Scanning Electron Microscopy (SEM) analysis was performed to access the surface alterations. The wear data were evaluated by three-way ANOVA and Tukey post-hoc test (α = 0.05). The factors 'antagonist', 'medium', 'restorative materials', and the interaction of all factors grouped by two and integrated showed statistical significance on the wear rates. A two-body test depicted no difference among all composites and enamel for wear rate, while a three-body test depicted differences among composites directly related to the filler content: EST < Z250 = CAP < ADO = HM < SFY. Dentin always showed the highest wear rates and enamel the lowest rates. The presence of food bolus (three-body test) led to higher wear rates in comparison to an only aqueous medium (two-body test). SEM analysis showed that different materials present specific wear patterns, regardless of the medium and the antagonist considered. Differently from enamel, dentin substrate was intensively prone to wear, regardless of the antagonist/medium. Resin composite substrates presented intermediate wear rates, depending directly on their filler content (% in weight).

Conservative Management of Dental Erosion in Adolescents with Medical Conditions

The prevalence of dental erosion among children and adolescents is trending higher in recent decades and is becoming a major concern. Dental erosion can be caused by either extrinsic or intrinsic acids or both. One of the established aetiological factors for dental erosion by intrinsic acid is the gastrooesophageal reflux disease. The degree of dental erosions may be influenced by any medical conditions that cause a reduction in salivary flow such as the salivary gland excision, autoimmune disease, radiation to the head and neck regions, and medications. If left untreated, the dental erosion can cause dentine hypersensitivity, loss of occlusal vertical height, and aesthetic problems. For effective management of dental erosion, the aetiology of each case must be determined, and its detection at an early stage is of prime importance. This case report illustrates the conservative management of dental erosion in two adolescent patients presented with their medical conditions and behaviour issues. The aim of the treatments was to preserve the vitality of the affected teeth. The treatments were successfully completed using a conservative approach, with the patients' medical conditions taken into consideration.

Ultrasonographic evaluation of jaw elevator muscles in young adults with bruxism and with and without attrition-type tooth wear: A pilot study

OBJECTIVE

This pilot study was planned to analyze masticatory activation in bruxism patients with and without attrition by ultrasonographic evaluation of mandibular adductor muscles.

METHODS

Sixty bruxism patients (group 1: 30 without attrition, group 2: 30 with attrition) and an age-sex matched control of 30 (group 3) were clinically examined. The thickness of bilateral temporalis and masseter muscles during clench and rest was measured by ultrasonography.

RESULTS

The mean muscle thicknesses were higher in bruxing patients than in controls. In group 2, the clench/rest ratio (C/R) of the right and left masseter and temporal muscles were higher than the control group (p = 0.03, p = 0.01, p = 0.04, p = 0.03, respectively).

CONCLUSION

The thickness of chewing muscles increases with bruxism. The occlusal forces in the teeth increase, and therefore, the tooth wear increases. Ultrasonographic muscle thickness can be used to determine muscle activity in bruxism patients.

Study of Associated Factors With Probable Sleep Bruxism Among Adolescents

STUDY OBJECTIVES

To evaluate the prevalence of probable sleep bruxism (SB) and its association with sleep features, orthodontic fixed appliance wearing, and extraoral and intraoral clinical signs and symptoms in a population of adolescents.

METHODS

Two hundred thirty-nine 12-year-old adolescents enrolled in private and public schools in Brumadinho, southeast Brazil, and their parents were invited to participate. They answered a questionnaire containing information regarding adolescents' sleep features and history of SB. Extraoral and intraoral examination was performed to identify some clinical signs (ie, absence of lip competence, presence of mouth breathing, clicks in the temporomandibular joint [TMJ], tooth wear) and symptoms (ie, pain in the masseter muscle upon palpation), and ongoing orthodontic treatment with fixed appliances. Parental report and clinical examination were used to determine probable SB. Descriptive statistics and logistic regression were performed to identify association of probable SB with independent variables.

RESULTS

Of 239 adolescents initially selected, 231 (96.6%) participated in the study. Prevalence of probable SB was 16.9%. Adolescents who snored during sleep (odds ratio [OR] = 3.14; 95% confidence interval [CI] = 1.47-6.70), adolescents who did not have clicks in the TMJ (OR = 3.37; 95% CI = 1.11-10.15), and those who wore orthodontic appliances (OR = 2.72; 95% CI = 1.04-7.14) were more likely to be in the group with probable SB.

CONCLUSIONS

Snoring, absence of clicks in the TMJ, and fixed appliance wearing were associated with probable SB among adolescents. This study adds to the ongoing research on SB in adolescents and its associated factors.

COMMENTARY

A commentary on this article appears in this issue on page 1281.

Digital workflow to rehabilitate worn dentition on a non-hinge simulated patient

This report describes the complete mouth rehabilitation of worn dentition by using a digital workflow on a non-hinge simulated patient. A dentiform was used to simulate a patient with loss of occlusal vertical dimension. Physical diagnostic waxing along with a digital workflow was then used to re-establish the occlusal vertical dimension at the interim and definitive restoration stages.

Comparative abrasive wear resistance and surface analysis of dental resin-based materials

OBJECTIVE

The objective of this study was to assess the surface properties (microhardness and wear resistance) of various composites and compomer materials. In addition, the methodologies used for assessing wear resistance were compared.

MATERIALS AND METHODS

This study was conducted using restorative material (Filtek Z250, Filtek Z350, QuiXfil, SureFil SDR, and Dyract XP) to assess wear resistance. A custom-made toothbrush simulator was employed for wear testing. Before and after wear resistance, structural, surface, and physical properties were assessed using various techniques.

RESULTS

Structural changes and mass loss were observed after treatment, whereas no significant difference in terms of microhardness was observed. The correlation between atomic force microscopy (AFM) and profilometer and between wear resistance and filler volume was highly significant. The correlation between wear resistance and microhardness were insignificant.

CONCLUSIONS

The AFM presented higher precision compared to optical profilometers at a nanoscale level, but both methods can be used in tandem for a more detailed and precise roughness analysis.

Parafunctional Behaviors and Its Effect on Dental Bridges

Parafunctional behaviors, especially bruxism, are not uncommon among patient visiting dentists’ clinics daily and they constitute a major dental issue for almost all dentists. Many researchers have focused on the definition, pathophysiology, and treatment of these behaviors. These parafunctional behaviors have a considerable negative impact on teeth and dental prothesis. In this review, we focused on the impact of parafunctional behaviors on dental bridges. We summarized the definitions, epidemiology, pathophysiology, and consequences of parafunctional behaviors. In addition, we reviewed previous dental literature studies that demonstrated the effect of bruxism or other parafunctional behaviors on dental bridges and dental prothesis. In conclusion, parafunctional behaviors are common involuntary movements involving the masticatory system. They are more prevalent among children. These behaviors have deleterious effects on dental structures. Causes of parafunctional behaviors include anxiety, depression, smoking, caffeine intake, sleep disorders, or central neurotransmitter dysfunction. Bruxism and other similar masticatory system activity cause dental fracture, loss, and weardown of enamel or teeth. They can also affect different types of dental protheses both fixed and removable types. Parafunctional behaviors shorten the life expectancy of these protheses, and damage residual dentition and denture-bearing tissues.

Alveolar ridge atrophy related to facial morphology in edentulous patients

OBJECTIVES

The morphology of the alveolar process determines the retention and stability of prosthetic restorations, thereby determining the result of the therapy. Considering that the edentulous jaws may be affected by the atrophy process, it was hypothesized that the morphology of the alveolar process of the maxilla may be dependent on the anterior facial height and anatomy of the mandible.

SUBJECTS AND METHODS

Twenty-five healthy edentulous Caucasian individuals were randomly chosen. Each subject underwent a lateral cephalogram before and after prosthetic rehabilitation. During exposition, newly made prostheses were placed in the patient's mouth. Teeth remained in maximal intercuspidation. Morphological parameters were evaluated according to the Ricketts, McNamara, and Tallgren's method.

RESULTS

An inversely proportional association was observed between patient age and the distal part of the maxilla. A statistically significant connection was noted between the vertical dimension of alveolar ridge and anterior total and lower facial height conditioned by prosthetic rehabilitation.

CONCLUSION

The height of the lateral part of the alveolar ridge of the maxilla remains in connection with the anterior total and lower facial height obtained in the course of prosthetic rehabilitation. The vertical dimension of the alveolar ridge of the maxilla seems to be in close relationship with the morphology of the lower jaw.

Worn is born: The role of the maxillo-mandibular relation in management of worn dentition

Worn dentition, often accompanied by occlusion changes such as reduced vertical dimension, poses a big challenge to both diagnosis and treatment. Current established causes fail to explain the observed tooth wearing patterns, and the treatments based on the documented pathogeneses are often unpredictable and require frequent maintenance. From the perspective of stomatognathic system, we postulate that the role of maxillo-mandibular relation is a crucial part in the tooth wear progression patterns, and should be well addressed in treatment planning. Incompatible occlusion with the inherent tendency of maxillo-mandibular relation has a profound effect on either wearing of natural teeth or failures of restorations. With the aid of cephalometrics and analysis of occlusion it is now possible to reduce this fallacy and achieve a harmony by re-designing the occlusion. According to our treated worn dentition cases, the restoring treatment guided by the tendency of maxillo-mandibular relation showed very promising results.

Tooth Wear Patterns among Khat and Shammah Users in Jazan City, Kingdom of Saudi Arabia: A Cross-sectional Survey

AIM

The effect of Khat and Shammah habits, with the para-functional jaw activities that accompany them, on the structure and integrity of the natural dentition has not yet been investigated. The literature lacks studies that identify the patterns of tooth wear among Khat and Shammah users. Therefore, this study is the first attempt to address this concern in Jazan City population, Kingdom of Saudi Arabia.

MATERIALS AND METHODS

A cross-sectional survey study was conducted among 300 recruits among dental clinics in Jazan City, Kingdom of Saudi Arabia from October 1, 2015, to April 30, 2016. Questionnaires were used for data collection on oral habits (Khat and Shammah use), age, gender, intake of acidic food or beverages, food habits (intake of fruits, grains, and vegetables), systemic diseases, oral hygiene habits (brushing frequency, technique, and type of toothbrush), parafunctional habits, stress, and acid reflux. Clinical examination was performed to assess the grade of tooth wear. Bivariate analysis was performed to determine the empirical relationship between the independent variables and outcomes. In addition, binary logistic regressions were used to measure the relationship between the independent variables and each of the dependent variables (presence of occlusal wear, tooth wear grade 0 through 4).

RESULTS

Khat and Shammah use was statistically significantly associated with tooth wear (p < 0.05). A significant association of tooth wear was observed with age, gender, intake of acidic food and beverages, oral hygiene habits, and stress.

CONCLUSION

Consumption of Khat and Shammah may be attributed as one of the major reasons associated with tooth wear among the Saudi population.

CLINICAL SIGNIFICANCE

The habitual use of Khat and Shammah causes tooth wear of varying severity, which may negatively affect esthetics, phonetics, and function and necessitate a complex restorative treatment.

Tooth wear and sleep quality: A study of police officers and non-police officers

OBJECTIVE

A cross-sectional study was performed to assess the prevalence of tooth wear facets and sleep disorders.

METHODS

The sample was divided into two groups: Group I: police officers (n = 144), and Group II: industrial workers (n = 142). A self-reported questionnaire, a clinical examination recorded in the dental records, and the Brazilian version of the Pittsburgh Sleep Questionnaire Index were used for data collection. Descriptive analysis, chi-squared and multiple logistic regression were used as statistical tests at a 5% significance level.

RESULTS

Group I was almost twice as likely to have tooth wear facets as was Group II (OR = 1.88 95% CI = 1.03-3.44). Sleep disorders were worse among the participants of Group I.

CONCLUSIONS

The type of profession exerted an influence on sleep disorders and the presence of wear facets among the groups, with police officers most likely to suffer from these disorders.