Forage silica and water content control dental surface texture in guinea pigs and provide implications for dietary reconstruction.

Recent studies have shown that phytoliths are softer than dental enamel but still act as abrasive agents. Thus, phytolith content should be reflected in dental wear. Because native phytoliths show lower indentation hardness than phytoliths extracted by dry ashing, we propose that the hydration state of plant tissue will also affect dental abrasion. To assess this, we performed a controlled feeding experiment with 36 adult guinea pigs, fed exclusively with three different natural forages: lucerne, timothy grass, and bamboo with distinct phytolith/silica contents (lucerne < grass < bamboo). Each forage was fed in fresh or dried state for 3 weeks. We then performed 3D surface texture analysis (3DST) on the upper fourth premolar. Generally, enamel surface roughness increased with higher forage phytolith/silica content. Additionally, fresh and dry grass feeders displayed differences in wear patterns, with those of fresh grass feeders being similar to fresh and dry lucerne (phytolith-poor) feeders, supporting previous reports that "fresh grass grazers" show less abrasion than unspecialized grazers. Our results demonstrate that not only phytolith content but also properties such as water content can significantly affect plant abrasiveness, even to such an extent that wear patterns characteristic for dietary traits (browser-grazer differences) become indistinguishable.

Influence of cavity depth and restoration of non-carious cervical root lesions on strain distribution from various loading sites.

BACKGROUND: We aimed to investigate the load-induced strain variation in teeth with unrestored and resin-based composite restored non-carious cervical lesions (NCCLs). METHODS: Twelve extracted premolars were provided for measuring buccal-side root NCCLs. Strain gauges were fixed at four measuring sites of each tooth, two at the buccal surface and two at the lingual surface. NCCLs were prepared with occlusal margins at the cemento-enamel junction. A static 9-kg load was applied at seven occlusal loading points: buccal cusp tip (BC), inner inclination of the BC, lingual cusp tip (LC), inner inclination of the LC, center of the mesial marginal ridge or distal marginal ridge, and center of the central groove. The strain was detected at each site in teeth with NCCL depths of 0 (control), 0.5, 1.0, and 1.5 mm. Each NCCL was restored using an adhesive composite resin, and the strains were re-measured. RESULTS: The strains at the NCCL occlusal and gingival margins decreased with increasing defect depths, and the effect was significant when the depth of the defect was 1.5 mm. Loading on the buccal and lingual cusps induced prominent strain variation. The strains at all depth distribution recovered to nearly intact conditions when the NCCLs were restored. CONCLUSIONS: NCCLs at 1.5 mm depth are detrimental, but they can be restored using resin composites. CLINICAL SIGNIFICANCE: The existence of NCCLs should not be ignored. The depth of the NCCL may affect the progression of the lesion. Resin composite restoration is an appropriate method for preventing persistent NCCL deterioration.

[Teeth wedge-shaped defects in adults of different age groups: remark to prevention and treatment]. / Klinovidnye defekty zubov u vzroslykh liudei raznykh vozrastnykh grupp: remarki k profilaktike i lecheniiu.

The aim of the study was to assess the treatment of teeth wedge defects in different age groups. Records of 383 patients (125 males and 258 females aged 22-85 years) treated in outpatient dental facilities with different ownership forms. It is shown that the medical care of patients with wedge-shaped teeth defects routinely consists of remineralization therapy and restoration of anatomical teeth shape regardless of the form of ownership. The extensiveness of dental rehabilitation as well as the use of more modern technologies are typical for private clinics and 96-100% of patients finished their treatment there. In the state and departmental institutions complete rehabilitation of wedge-shaped defects was provided in 45.5-58.0% and 54.3-83.9, respectively. The paper also highlights the drawbacks of primary medical documentation identified in medical institutions of all forms of ownership.

Effects of Erosion Protocol Design on Erosion/Abrasion Study Outcome and on Active Agent (NaF and SnF2) Efficacy.

There is no standard for testing anti-erosive/anti-abrasive agents, making the assessment and comparison of study results difficult. Factors which are varied in study designs are amongst others the erosive medium regarding concentration and pH or movement type of acid. The present study therefore investigated the impact of these factors on dimension of tissue loss and on efficacy of active agents used as anti-erosive/anti-abrasive therapeutics. In 8 experiments, consisting of 8 groups each (n = 20 each), resulting in a total of 64 groups, enamel specimens were demineralised (10 days, 6 × 2 min/day) using different acids (1, 0.5 and 0.3% citric acid at native pH 2.3, 2.5 and 2.8, respectively, and 0.3% citric acid adjusted to pH 3.6) with two different movement types (jerky or smooth). Specimens were immersed (2 × 2 min/day) in slurries of 1,450 ppm F- toothpaste (NaF), 1,450 ppm F- and 3,436 ppm Sn2+ toothpaste (NaF/SnF2), 970 ppm F- and 3,000 ppm Sn2+ gel (SnF2) or placebo, or were additionally brushed during immersion (15 s, 200 g). All groups were in between stored in a mineral salt solution. Tissue loss was determined profilometrically. Movement type, pH and concentration of acid had a substantial impact on study outcome. The combination of jerky movement and concentrated acid masked, to some extent, differences between erosive and erosive-abrasive tissue loss. The acid at low concentration (0.3%), independent of pH, was too mild to produce any tissue loss. The model with the best ability to demonstrate effects of abrasive impacts and active agents used the 1% acid concentration combined with smooth acid movements.

Effect of tooth brush abrasion and thermo-mechanical loading on direct and indirect veneer restorations.

OBJECTIVES: This study investigated toothbrush abrasion and in vitro aging on ceramic (indirect technique) and composite veneers (direct technique). MATERIALS AND METHODS: Identical composite and individual human incisors were restored with industrially preformed composite veneers, indirectly produced ceramic veneers, and direct composite restorations. Surface roughness was determined before and after tooth brushing. A 5-year period of oral service was simulated by thermal cycling and mechanical loading (TCML). After TCML, all specimens were examined with microscopy and scanning electron microscopy. Specimens without failures during TCML were loaded until failure. STATISTICS: analysis of variance; Bonferroni's post hoc analysis, Kaplan-Meier-Log Rank test (α = 0.05). RESULTS: Tooth brushing yielded a non-significant increase (p = 0.560) in roughness in all materials (industrial veneer, 0.12+/-0.07 µm, direct restoration, 0.18+/-0.14 µm, ceramic, 0.35+/-0.16 µm). No significant differences in roughness could be determined between the materials, neither before nor after testing (p < 0.001). After TCML of artificial teeth, direct and preformed composite veneers on composite teeth showed no failures or damages. Two ceramic veneers showed cracking in the labial area. After TCML of human teeth, transmission microscopy indicated a facial crack in a ceramic veneer and chipping in the cervical area of a preformed veneer. Two direct composite veneers lost retention. No significantly different survival rates were found between the three veneer groups. Fracture force on human teeth varied between 527.8+/-132.4 N (ceramic), 478.3+/-165.4 N (preformed composite), and 605.0+/-263.5 N (direct composite). CONCLUSION: All materials revealed comparable wear resistance. Indirect ceramic, direct restorative composite, and preformed composite veneers showed comparable failure rates and satisfying longevity. CLINICAL RELEVANCE: The results indicate similar longevity of the chosen materials for veneer restorations.

A "midline dilemma" in an adult mutilated dentition.

Orthodontic treatment for adult patients who have mutilated dentitions can be clinically challenging. A 58-year-old man with several occlusally abraded teeth, a congenitally missing maxillary lateral incisor, and prior implant placement sought orthodontic treatment and restoration. Prosthetic restoration would not be possible. The "dilemma" for this patient was whether to trephine and remove an existing implant and make space for a new lateral incisor implant, or to restore the maxillary canine as a lateral incisor.

Interactive treatment planning in toothwear: are we doing it right?

UNLABELLED: Toothwear is now common, especially in younger patients, with high demand for the restoration of the damaged teeth which is likely to increase further over time. Fixed prosthodontic options range from direct composite resin to conventional tooth preparation and cemented indirect restorations. This paper summarizes the views of a variety of clinicians on a plan delivered to a patient with toothwear in secondary care and explores the possible reasons for the variation in decision-making in the treatment of toothwear. CLINICAL RELEVANCE: With levels of toothwear increasing, the clinician needs to be aware of the different treatment modalities which are appropriate.

Tooth surface loss: causes, management, and prevention.

OBJECTIVES: Tooth wear, also referred to as tooth surface loss, occurs due to causes other than caries. This involves the loss of hard tissues, namely enamel, dentin, and/or cementum. Types of tooth wear/tooth surface loss are abrasion, abfraction, attrition, and erosion. These multifactorial conditions can be caused by factors such as lifestyle, diet, or even habits, and may not be symptomatic. The focus of this article is to provide clinicians with detailed examples and explanations of the causes of tooth loss to aid in early diagnosis. Through early identification, the preventive measures outlined can be implemented to avoid excessive tooth wear. The provision of a treatment flowchart and general treatment recommendations aims to help clinicians determine when to restore these lesions and the most appropriate treatment measures for the four types of wear. METHOD AND MATERIALS: The PubMed (MEDLINE) search engine was used to gather information on teeth restricted to a 5-year period (26 August 2018 to 25 July 2022). Only English-language studies and reviews with the best balance of sensitivity and specificity were considered. A Boolean search of the PubMed dataset was implemented to combine a range of keywords: ("tooth wear" OR tooth attrition OR tooth erosion OR tooth abrasion OR tooth abfraction). Additional articles were selected through Google Scholar. RESULTS: By this process, many articles and studies were obtained, and the 48 most relevant published studies were chosen and used in the current review. CONCLUSION: Tooth wear affects an increasing number of individuals and can have detrimental effects physically, mentally, and emotionally. It is important to stress early diagnosis and management of tooth wear through monitoring, prevention, and treatment where indicated.

[Optimization of treatment of wedge-shaped tooth defects with hyperesthesia].

Development of tooth wedge-shaped defect leads to a gradual loss of hard tissue and is characterized by pain. Most often patients complain of pain and aesthetic defect that adversely affects the emotional status and quality of life. Search for adequate means and methods of treatment providing increased resistance of dental hard tissues and reducing hyperesthesia is challenging for dentists. Wedge-shaped defect and hyperesthesia as concomitant symptom was found in the city of Ufa in the 5.65 and 63.0% of dental patients, respectively. Analysis of the questionnaires revealed a relationship between the sociological parameters (gender, age, profession) and the patient's quality of life. Improvement of all clinical manifestations was observed in the result of complex treatment.

Use of additive dentistry decreases risk by minimizing reduction.

This case required enhancement of esthetics and reduction of long-term risk of pathologic tooth wear and decay, as well as minimizing erosion caused by innate and environmental influences. The author weighed patient expectations, diet, treatment of teeth, and age to create a treatment plan that would conserve tooth structure while accomplishing the goals of the case. The patient's dentition was restored utilizing intact enamel, adhesive dentistry, and etchable ceramic materials that require less than 1 mm of occlusal reduction without a significant loss of strength. In this case, opening the vertical dimension of occlusion--which was done to increase the height of both the maxillary and mandibular arches, in keeping with the patient's esthetic desires--eliminated the need to remove excessive amounts of healthy tooth structure and facilitated treatment of the occlusal dysfunction.

"The mother of all black triangles" case.

Before the Bioclear matrix and a disciplined approach to composite treatment of black triangles, many treatments ended with significant compromise in periodontal health. Many cases debonded soon after placement. Others suffered problems with stain. Nonetheless, our patients are hopeful for a better solution. The interdental papilla serves as both a functional and aesthetic asset. Anatomically ideal interproximal composite shapes that are mirror smooth can serve as a predictable scaffold to regain this valuable gingival architecture. Clean enamel surfaces can be leveraged to permanently retain the restorations. However, the reader is cautioned that to attempt this elective procedure using no magnification, without a strict adherence to dentin detoxification with a blasting appliance, and using a flat matrix, nontreatment or referral is recommended. Our profession can change its thought processes, retrain its hands and expand its armamentarium to perform techniques that were previously impossible.

Two-year clinical performance of Clearfil SE and Clearfil S3 in restoration of unabraded non-carious class V lesions.

This study was undertaken to evaluate the two-year clinical performance of a self-etching primer and a self-etching adhesive, both of which employ the same acidic monomer. Forty pairs of restorations of AP-X hybrid resin composite (Kuraray Co, Ltd, Osaka, Japan) were placed in caries-free cervical erosion/abfraction lesions. Based on insensitivity to air, the dentin in 62% of these lesions was considered to be sclerotic. The restorations were placed with no abrasion of tooth surfaces, except for cleaning with plain pumice and no use of phosphoric acid etching, which is counter to the manufacturer's instructions that call for etching of unprepared enamel. One restoration from each pair was placed using Clearfil SE Bond, an adhesive employing a self-etching primer, and the other was placed using Clearfil S3 Bond, a self-etching adhesive. To emulate the results likely to occur in a private practice, the restorations were placed by well-educated, experienced clinicians who had no particular expertise in adhesive dentistry research and who placed the restorations according only to their interpretation of the manufacturer's instructions. The restorations were clinically evaluated at baseline and at 6, 12 and 24 months, using modified Ryge/USPHS criteria. For both products, retention of 81%-84% of the restorations was observed over two years, which is lower than has been previously observed with these products and is likely due to limitations in the manufacturer's instructions compounded by inexperience of the operators in adhesive dentistry research. One restoration placed with each adhesive demonstrated secondary caries, which was probably attributable to the study being conducted in a non-fluoridated area and which reduced the percentages of clinically successful restorations to 78%-81%. No statistically significant difference (p = 0.50) between the two adhesives was observed in overall performance.

Reconstruction of the vertical jaw relation using CAD/CAM.

There can be severe loss of the vertical dimension of occlusion due to chemical, mechanical and traumatic causes. This can give rise to both esthetic and functional problems for the patient. Restoration is possible usually only by redesigning the occlusal surfaces. The prosthetic readjustment of the vertical jaw relation represents a considerable intervention in the stomatognathic system, requiring predictable, minimally invasive methods. Long-term provisional solutions clearly superior to pure splint therapy can be produced by means of new CAD/CAM techniques. They are inserted permanently and only in this way can the patient test the new occlusal situation and the success of treating functional disorders be verified. A further major advantage then becomes apparent when the final restoration is produced. The previously adjusted and tested occlusion is retained and every tooth can be treated and restored individually. Long treatment sessions are thus a thing of the past.

Three-year evaluation of posterior vertical bite reconstruction using direct resin composite--a case series.

The use of resin composite materials to restore the complete occlusion of worn teeth is controversial and data are scarce. In this case series, the authors report on seven cases of progressive mixed erosive/abrasive worn dentition (85 posterior teeth) that have been reconstructed with direct resin composite restorations. In all patients, either one or both tooth arches was completely restored using direct resin composite restorations. All patients were treated with standardized materials and protocols. In five patients, a wax-up-based template was used to avoid freehand build-up techniques and to ensure optimal anatomy and function. All patients were re-assessed after a mean service time of three years (mean 35 +/- 5 months) using USPHS criteria. Subjective patient satisfaction was measured using visual analogue scales (VAS). The overall quality of the restorations was good, with predominantly determined "Alpha"-scores. Only the marginal quality showed small deteriorations, with "Beta" scores of 37% and 45% for marginal discoloration and integrity, respectively. In general, the composite showed signs of wear facets that resulted in 46% "Beta" scores within the anatomy scores. Small restoration fractures were only seen in two restorations, which were reparable. Two teeth were excluded from the evaluation, as they have been previously repaired due to fracture after biting on a nut. The results were very favorable, and the patients were satisfied with this non-invasive and economic treatment option, which still has the characteristic of a medium-term rehabilitation. The outcomes were comparable to other direct composite restorations successfully applied in adhesive dentistry.

A questionnaire based study to investigate the variations in the management of tooth wear by UK and prosthodontists from other countries.

The aim of this research project was to compare how the management of toothwear differs between specialist prosthodontists in the United Kingdom and other countries' specialist prosthodontists. A questionnaire on the management of toothwear was sent to two groups of 100 specialist prosthodontists randomly selected in the United Kingdom and overseas. The response rate was 64% for UK and 54% for overseas respondents. Similarities existed in the management of bruxism and the prevention of erosion, but there were significant differences between the two groups regarding treatment of palatal erosion, short clinical crowns and wear on the lower incisors. UK prosthodontists more often use resin-based materials and a showed a more conservative approach to treatment of tooth wear compared to their overseas colleagues.

Restorations of endodontically treated teeth: new concepts, materials, and aesthetics.

The care of endodontically treated teeth has been one of the greatest challenges in restorative dentistry. Left unrestored, endodontically treated teeth have complications that include coronal leakage and subsequent reinfection of the root canal system. These teeth are at risk for fracture, since they become predisposed to structural compromise when compared to their properly restored counterparts. As demonstrated herein, caries, previous restorations, fractures, wear, erosion, and endodontic procedures each require careful consideration and timely tooth reconstruction to ensure a favorable prognosis.

Alternative restorative approach for treatment of patient with extremely worn dentition.

Changes in tooth structure, missing teeth and decreased vertical dimension of occlusion severely deteriorate the stomatognathic system. This case report describes the treatment of a patient with loss of vertical dimension due to severe wear of maxillary and mandibular teeth. An occlusal splint was used to create an optimum maxillomandibular relationship and to provide restorative space prior to restoration of the remaining teeth. The restoration was accomplished with a hybrid composite material. This treatment has been a less-expensive alternative to full-mouth, fixed porcelain/metal-porcelain restoration while conserving the remaining tooth tissue.

Coronally positioned flap plus resin-modified glass ionomer restoration for the treatment of gingival recession associated with non-carious cervical lesions: a randomized controlled clinical trial.

BACKGROUND: The aim of this randomized clinical trial was to evaluate the treatment of gingival recession associated with non-carious cervical lesions by a coronally advanced flap alone (CAF) or in combination with a resin-modified glass ionomer restoration (CAF+R). METHODS: Nineteen subjects with bilateral Miller Class I buccal gingival recessions associated with non-carious cervical lesions were selected. The recessions were assigned randomly to receive CAF or CAF+R. Bleeding on probing (BOP), probing depth (PD), relative gingival recession (RGR), clinical attachment level (CAL), non-carious cervical lesion height (CLH), and dentin sensitivity (DS) were measured at baseline; 45 days; and 2, 3, and 6 months postoperatively. Keratinized tissue width (KTW) and keratinized tissue thickness (KTT) were measured at baseline and 6 months. The height of the non-carious cervical lesion located on the root and crown were estimated, allowing calculation of root coverage. RESULTS: Both groups showed statistically significant gains in CAL and soft tissue coverage. The differences between groups were not statistically significant for BOP, PD, RGR, CAL, KTW, and KTT after 6 months. The percentages of CLH covered were 56.14% +/- 11.74% for CAF+R and 59.78% +/- 11.11% for CAF (P >0.05). The root and crown surfaces affected by the non-carious cervical lesion were 1.67 +/- 0.31 mm and 0.96 +/- 0.29 mm, respectively, for CAF+R and 1.59 +/- 0.37 mm and 1.01 +/- 0.33 mm, respectively, for CAF. The estimated root coverage was 88.02% +/- 19.45% for CAF+R and 97.48% +/- 15.36% for CAF (P >0.05). CAF+R reduced DS significantly compared to CAF (P <0.05). CONCLUSIONS: Both procedures provided similar soft tissue coverage after 6 months. Despite the fact that a greater reduction in DS was observed after CAF+R, longitudinal observations are necessary to confirm these results.

The efficacy of a highly concentrated fluoride dentifrice on bovine enamel subjected to erosion and abrasion.

BACKGROUND: Researchers have proposed the use of fluoride for the prevention of enamel wear; however, only limited information is available about the impact of fluoridated dentifrices. Because tooth wear is a well-recognized dental problem, the authors conducted an in situ, ex vivo study to assess the efficacy of a highly concentrated fluoride dentifrice on bovine enamel subjected to erosion and abrasion. METHODS: The authors conducted a double-blind, crossover in situ study consisting of three phases (seven days each). In each phase, the authors tested one of the dentifrices (5,000 parts per million fluoride [F]; 1,100 ppm F; no F). They performed erosive challenges with the use of cola drink (60 seconds, four times per day) and abrasive challenges via toothbrushing (30 seconds, four times per day). The authors determined the enamel loss via profilometry. RESULTS: The authors tested the data by using two-way analysis of variance (P < .05). For the erosion-plus-abrasion condition, the study results showed that enamel wear was significantly higher than that with erosion alone. The findings showed no significant differences between the dentifrices regarding enamel wear. CONCLUSIONS: Within the in situ, ex vivo conditions of this study, the authors concluded that the highly concentrated fluoride dentifrice did not have a protective effect on enamel against erosion and erosion plus toothbrushing abrasion. CLINICAL IMPLICATIONS: Patients at risk of developing enamel erosion should benefit from preventive measures other than fluoride dentifrice, because even a highly concentrated fluoride dentifrice does not appear to prevent enamel erosion.