Dental Caries and Its Management

Objectives

In recent years, the management of dental caries has evolved significantly. Caries prevention, early detection, and a diagnosis based on risk indicators and risk factor assessments are the most current practical approaches. Furthermore, as proposed in minimally invasive dentistry, the new management approaches preserve healthy tissue and maintain pulp vitality. This article overviews the latest minimally invasive dental caries management and treatment options. The information will assist the reader in the early detection, diagnosis, and treatment of dental caries.

Materials and Methods

The PubMed (MEDLINE) search engine was used to gather the most relevant information on dental caries. The search was restricted to five years (May 30, 2018-May 29, 2022), and only English-language studies were accessed. A Boolean search of the PubMed data set was implemented to combine a range of keywords. The following filters were applied: abstract, free full text, full text, clinical trial, randomised control trial, systematic review, meta-analysis, and review. More studies were also obtained by manual searches from Google Scholar and textbooks on dental caries.

Results

By using this process, 683 articles and studies were obtained. The most relevant published studies were chosen and used in the current review. The selected articles are included in the references list. However, the search extended to cover the last five years as our understanding and management of dental caries have changed significantly.

Conclusions

Early detection and diagnosis of caries based on risk indicators and risk factor assessments are effective. Furthermore, minimally invasive restorative techniques are beneficial in managing dental caries and preserving healthy tissue and should be used whenever possible. This new information, knowledge, and materials should encourage professionals to implement this method. Having a strategy and system based on patient-centred care is critical, and our dental responsibilities must prioritise patient-centred care.

Rehardening and the Protective Effect of Gamma-Polyglutamic Acid/Nano-Hydroxyapatite Paste on Surface-Etched Enamel

Many revolutionary approaches are on the way pertaining to the high occurrence of tooth decay, which is an enduring challenge in the field of preventive dentistry. However, an ideal dental care material has yet to be fully developed. With this aim, this research reports a dramatic enhancement in the rehardening potential of surface-etched enamels through a plausible synergistic effect of the novel combination of γ-polyglutamic acid (γ-PGA) and nano-hydroxyapatite (nano-HAp) paste, within the limitations of the study. The percentage of recovery of the surface microhardness (SMHR%) and the surface parameters for 9 wt% γ-PGA/nano-HAp paste on acid-etched enamel were investigated with a Vickers microhardness tester and an atomic force microscope, respectively. This in vitro study demonstrates that γ-PGA/nano-HAp treatment could increase the SMHR% of etched enamel to 39.59 ± 6.69% in 30 min. To test the hypothesis of the rehardening mechanism and the preventive effect of the γ-PGA/nano-HAp paste, the surface parameters of mean peak spacing (Rsm) and mean arithmetic surface roughness (Ra) were both measured and compared to the specimens subjected to demineralization and/or remineralization. After the treatment of γ-PGA/nano-HAp on the etched surface, the reduction in Rsm from 999 ± 120 nm to 700 ± 80 nm suggests the possible mechanism of void-filling within a short treatment time of 10 min. Furthermore, ΔRa-I, the roughness change due to etching before remineralization, was 23.15 ± 3.23 nm, while ΔRa-II, the roughness change after remineralization, was 11.99 ± 3.90 nm. This statistically significant reduction in roughness change (p < 0.05) implies a protective effect against the demineralization process. The as-developed novel γ-PGA/nano-HAp paste possesses a high efficacy towards tooth microhardness rehardening, and a protective effect against acid etching.

Infiltration and sealing for managing non-cavitated proximal lesions: a systematic review and meta-analysis

Background

Infiltration and sealing are micro-invasive treatments for arresting proximal non-cavitated caries lesions; however, their efficacies under different conditions remain unknown. This systematic review and meta-analysis aimed to evaluate the caries-arresting effectiveness of infiltration and sealing and to further analyse their efficacies across different dentition types and caries risk levels.

Methods

Six electronic databases were searched for published literature, and references were manually searched. Split-mouth randomised controlled trials (RCTs) to compare the effectiveness between infiltration/sealing and non-invasive treatments in proximal lesions were included. The primary outcome was obtained from radiographical readings.

Results

In total, 1033 citations were identified, and 17 RCTs (22 articles) were included. Infiltration and sealing reduced the odds of lesion progression (infiltration vs. non-invasive: OR = 0.21, 95% CI 0.15–0.30; sealing vs. placebo: OR = 0.27, 95% CI 0.18–0.42). For both the primary and permanent dentitions, infiltration and sealing were more effective than non-invasive treatments (primary dentition: OR = 0.30, 95% CI 0.20–0.45; permanent dentition: OR = 0.20, 95% CI 0.14–0.28). The overall effects of infiltration and sealing were significantly different from the control effects based on different caries risk levels (OR = 0.20, 95% CI 0.14–0.28). Except for caries risk at moderate levels (moderate risk: OR = 0.32, 95% CI 0.01–8.27), there were significant differences between micro-invasive and non-invasive treatments (low risk: OR = 0.24, 95% CI 0.08–0.72; low to moderate risk: OR = 0.38, 95% CI 0.18–0.81; moderate to high risk: OR = 0.17, 95% CI 0.10–0.29; and high risk: OR = 0.14, 95% CI 0.07–0.28). Except for caries risk at moderate levels (moderate risk: OR = 0.32, 95% CI 0.01–8.27), infiltration was superior (low risk: OR = 0.24, 95% CI 0.08–0.72; low to moderate risk: OR = 0.38, 95% CI 0.18–0.81; moderate to high risk: OR = 0.20, 95% CI 0.10–0.39; and high risk: OR = 0.14, 95% CI 0.05–0.37).

Conclusion

Infiltration and sealing were more efficacious than non-invasive treatments for halting non-cavitated proximal lesions.

Anti-demineralization characteristics of surface pre-reacted glass-ionomer (S-PRG) filler-containing varnishes

This study investigated the anti-demineralization effects of surface pre-reacted glass-ionomer (S-PRG) filler-containing varnishes. Thirty-five bovine root specimens were divided into five treatment groups, with seven specimens each coated with 1) MI varnish (MIV), 2) F varnish (FV), 3) PRG varnish I (PV), 4) PRG varnish II (with sodium fluoride added, PVF), and 5) acid-resistant nail varnish (Control). A 3×1 mm area of the dentin surface adjacent to each varnish was demineralized for one week at 37°C. Integrated mineral loss (IML) of these lesions was determined by transverse microradiography, as was the amount of fluoride released by each material. IML was significantly lower in the PV and PVF groups than in the Control group, and was significantly lower in the PVF than in the MIV and FV groups. These findings indicated that S-PRG filler-containing varnishes, especially varnish containing sodium fluoride, had superior anti-demineralization effects on root dentin.

Effect of CPP-ACP on remineralization of artificial caries-like lesion: an in situ study

The purpose of this double-blind, randomized, crossover in situ study is to compare remineralization of preformed enamel lesions by casein phosphopeptide-stabilized amorphous calcium phosphate (CPP-ACP) and fluoride dentifrice products. During each of four 10-day experimental legs, 10 participants wore intraoral removable palatal acrylic appliances with four human enamel slabs with preformed lesions. A 0.03-mL treatment paste was dripped extraorally onto the enamel blocks once a day for 3 min. The four randomly allocated treatments were as follows: CO- Control: silica dentifrice without fluoride; MP: MI Paste; MPP: MI Paste Plus and FD: Fluoride dentifrice - 1100 ppm F as NaF). Knoop surface hardness (SH) test was performed in three stages (T0 - sound enamel, T1 - after preformed lesion, and T2 - after treatment) and the cross-sectional hardness (CSH) test was performed after treatment using a 50-gram Knoop load for 15 s. Knoop hardness number (KHN) was similar between treatments. %SHr was significantly higher in the MP, FD, and MPP when compared to CO group (Kruskal-Wallis and Mann-Whitney tests, p < 0.05). Harder enamel was found in MP (75 μm) and FD groups at 75 to 175 μm. Treatment with DF, MP, and MPP promoted an increase of 20.27%, 19.24%, and 14.71%, respectively, in Integral Hardness Change (ΔIHC) when compared to CO (p<0.05). Remineralizing agents (MP, MPP, and DF) were able to inhibit demineralization of human enamel subjected to high cariogenic challenge in situ. DF had the greatest preventive potential against the progression of carious lesions.

Synthesis of plate-like β-tricalcium phosphate nanoparticles and their efficiency in remineralization of incipient enamel caries

The purpose of this study was to synthesize nano-sized β-tricalcium phosphate (nano-TCP) particles and determine its concentration-dependent properties on incipient enamel caries lesions. Nano-TCP was synthesized as a wet chemical through a method using low concentration of precursors and low addition rate of calcium nitrate tetrahydrate as a second phase. Morphology and phase composition of the particles were analyzed by SEM, XRD, and EDXA techniques. Incipient enamel lesions were created in human premolars with an acidic buffer. The teeth were then incubated in aqueous dispersions of nano-TCP as remineralization solutions. Sodium fluoride solution and deionized water were used as positive and negative control groups, respectively. The quality and thickness of the remineralized layer on enamel were investigated using SEM. The data were statistically analyzed by analysis of variance (ANOVA) and post hoc Tukey’s test. The synthesized nano-TCP mostly consisted of porous platelet-like crystals of 50–100 nm thickness and pore diameters of 100–300 nm. SEM observation showed that a homogenous layer was formed on the surface of the enamels remineralized in nano-TCP solutions. The thickness of the mineralized layer was dependent on the incubation time and nano-TCP concentration.

Effects of soy and bovine milk beverages on enamel mineral content in a randomized, double-blind in situ clinical study

Soy beverages are promoted as healthy alternatives to bovine milk even though they can contain added sugar.

OBJECTIVES

To compare enamel mineral content after consumption of bovine milk or a soy beverage in a double-blind, randomized, cross-over in situ clinical study.

MATERIALS AND METHODS

Human enamel slabs with subsurface lesions were prepared and inserted into intra-oral appliances worn by volunteers who consumed 200 ml of either bovine milk or a soy beverage over a 60 s period once a day for 15 days. Enamel lesion depth and mineral content were measured using transverse microradiography. Saliva samples were collected immediately after consuming the beverages and calcium, inorganic phosphate and fluoride levels analysed. Data were statistically analysed using a linear mixed model.

RESULTS

Depth of the enamel subsurface lesions increased by 7.1 ± 2.0 μm and mineral content decreased by 47 ± 22 vol% min.μm after consumption of the soy beverage indicating demineralization. However, after consumption of bovine milk the depth of the lesions decreased by 7.6 ± 3.5 μm and mineral content increased by 202 ± 43 vol% min.μm indicating remineralization. The changes were significantly different (p < 0.001) between the two beverages. Fluoride levels were similar in the saliva samples for both beverages, however the calcium and inorganic phosphate levels for the bovine milk group were significantly higher (p < 0.02) than those for the soy beverage group.

CONCLUSIONS

In this randomized, double-blind in situ clinical trial consumption of a soy beverage demineralized enamel whereas bovine milk produced remineralization.

CLINICAL SIGNIFICANCE

Although soy beverages are promoted as healthy alternatives to bovine milk the added sugar and low calcium bioavailability of the soy drink makes frequent consumption a caries risk. (Trial registration no. ISRCTN19137849).

"Setting the scene in early childhood" - an MID approach for life

This article presents a discussion paper for both consideration and implementation of Minimal Intervention Dentistry (MID) principles by the general dental practitioner. It argues that if these concepts can be adopted in early childhood by both the community and the profession, "Teeth for Life" can become a reality for all. Oral Health promoting behaviours can be nurtured and supported from infancy and developed into everyday living practice for a lifetime thereby maintaining an optimal quality of life. MID techniques have become more refined and supported by scientific research in the recent times and should be considered an essential clinical guideline for the future disease management.

The in vitro remineralizing effect of CPP-ACP and CPP-ACPF after 6 and 12 weeks on initial caries lesion

Objective:

The aim of this in vitro study was to determine the effects of remineralization promoting agents containing casein phosphopeptide-stabilized amorphous calcium phosphate (CPP-ACP), or CPP-ACP in combination with fluoride (CPP-ACPF) on artificial white spot lesions (WSLs) after 6 and 12 weeks.

Methodology:

White spot lesions were created on 123 sectioned premolars (246 specimens) with a demineralization solution during a 96 hours pH-cycling regime. Two experimental groups were created: a CPP-ACP group (Tooth Mousse™), and a CPP-ACPF group (Mi Paste Plus™). Additionally, two control groups were created, one using only a conventional toothpaste (1450 ppm fluoride) and another one without any working agents. All teeth were also daily brushed with the conventional toothpaste except the second control group. Tooth Mousse™ and Mi Paste Plus™ were applied for 180 seconds every day. The volume of demineralization was measured with transverse microradiography. Six lesion characteristics regarding the lesion depth and mineral content of WSLs were also determined.

Results:

The application of CPP-ACP and CPP-ACPF had a significant regenerative effect on the WSLs. Compared to Control group 1 and 2 the volume of demineralization after 6 weeks decreased significantly for CPP-ACP (respectively p<0.001 and p<0.001) and CPP-ACPF (respectively p=0.001 and p=0.003). The same trend was observed after 12 weeks. For the CPP-ACPF group, WSL dimensions decreased significantly between 6 and 12 weeks follow-up (p=0.012). The lesion depth reduced significantly after application of CPP-ACP and CPP-ACPF but increased significantly in the Control groups. Mineral content increased for CPP-ACP and CPP-ACPF after an application period of 12 weeks, but this was only significant for CPP-ACP.

Conclusions:

Long-term use of CPP-ACP and CPP-ACPF in combination with a conventional tooth paste shows beneficial effects in the recovery of in vitro subsurface caries lesions.

Self-assembly of dental surface nanofilaments and remineralisation by SnF2 and CPP-ACP nanocomplexes

Dental caries, erosion and hypersensitivity are major public health problems. SnF₂ is used widely in oral care products to help prevent/treat these conditions. Casein phosphopeptide-stabilised amorphous calcium phosphate nanocomplexes (CPP-ACP) are a biomimetic nanotechnology of salivary phosphopeptide-ACP complexes that deliver bioavailable calcium and phosphate ions to promote dental remineralisation (repair). We show here using in vitro studies and a double-blind, randomised controlled, cross-over design in situ clinical trial that SnF₂ and CPP-ACP interact to form a nanofilament coating on the tooth surface and that together they are superior in their ability to promote dental remineralisation. Sn(II) by cross-linking the CPP-ACP helps to stabilise the complexes which improves delivery to the tooth surface and enhances binding and ion incorporation into tooth mineral. The combination of SnF₂ and CPP-ACP in oral care products may significantly improve their efficacy in prevention/treatment of dental caries/erosion and hypersensitivity.

CPP-ACP Promotes SnF2 Efficacy in a Polymicrobial Caries Model

Dental caries is associated with plaque dysbiosis, leading to an increase in the proportions of acidogenic and aciduric bacteria at the expense of alkali-generating commensal species. Stannous fluoride (SnF₂) slows the progression of caries by remineralization of early lesions but has also been suggested to inhibit glycolysis of aciduric bacteria. Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) promotes fluoride remineralization by acting as a salivary biomimetic that releases bioavailable calcium and phosphate ions, and the peptide complex has also been suggested to modify plaque composition. We developed a polymicrobial biofilm model of caries using 6 bacterial species representative of supragingival plaque that were cultured on sound human enamel and pulsed with sucrose 4 times a day to produce a high cariogenic challenge. We used this model to explore the mechanisms of action of SnF₂ and CPP-ACP. Bacterial species in the biofilms were enumerated with 16S rRNA gene sequence analyses, and mineral loss and lesion formation were determined in the enamel directly under the polymicrobial biofilms via transverse microradiography. The model tested the twice-daily addition of SnF₂, CPP-ACP, or both. SnF₂ treatment reduced demineralization by 50% and had a slight effect on the composition of the polymicrobial biofilm. CPP-ACP treatment caused a similar inhibition of enamel demineralization (50%), a decrease in Actinomyces naeslundii and Lactobacillus casei abundance, and an increase in Streptococcus sanguinis and Fusobacterium nucleatum abundance in the polymicrobial biofilm. A combination of SnF₂ and CPP-ACP resulted in a greater suppression of the acidogenic and aciduric bacteria and a significant 72% inhibition of enamel demineralization.

Importance of bioavailable calcium in fluoride dentifrices for enamel remineralization

OBJECTIVES

To compare remineralization of enamel subsurface lesions by fluoride dentifrices with added calcium in a double-blind, randomized, cross-over, in situ study.

METHODS

Human enamel with subsurface lesions were prepared and inserted into intra-oral appliances worn by volunteers. A slurry (1 g toothpaste/4 ml H₂O) was rinsed for 60 s, 4 times per day for 14 days. Seven toothpastes were tested: (i) 1450 ppm F (NaF), (ii) 5000 ppm F (NaF), (iii) 1450 ppm F (MFP) with calcium sodium phosphosilicate (CSP), (iv) 1450 ppm F (MFP) with CaCO₃/Arg, (v) 1150 ppm F (SnF₂) with amorphous calcium phosphate (ACP), (vi) 1100 ppm F (NaF) with casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and (vii) 5000 ppm F (NaF) with functionalized tri-calcium phosphate (TCP). Total (acid soluble) and bioavailable (water soluble) calcium, inorganic phosphate and fluoride levels of the dentifrices were measured using ion chromatography (F/MFP) and spectrophotometry (Ca and inorganic phosphate). Enamel lesion mineral content was measured using transverse microradiography. Data were statistically analysed using a linear mixed model.

RESULTS

All calcium and fluoride containing toothpastes released > 90% of bioavailable fluoride and were superior to the respective fluoride alone toothpastes in remineralization of enamel subsurface lesions. The level of remineralization followed the order: CPP-ACP/1l00 ppm F > ACP/1150 ppm F = TCP/5000 ppm F > 5000 ppm F = CaCO₃/Arg/1450 ppm F = CSP/1450 ppm F > 1450 ppm F. Bioavailable calcium levels significantly correlated with enhanced remineralization of enamel subsurface lesions.

CONCLUSIONS

Bioavailable calcium in fluoride dentifrices enhanced remineralization of enamel subsurface lesions.

Efficacy of 4-year treatment of icon infiltration resin on postorthodontic white spot lesions

White spot lesions are defined as enamel surface and sub surface demineralisation, although these lesions can be reversed and do not form cavities. Infiltration using fluid resin proved to be a valid micro-invasive alternative compared with traditional conservative therapy. This has allowed treatment without any trauma (no use of local anaesthesia and cavity preparation) of numerous lesions in only one session with stable clinical (mechanical stability, enamel hardness, conservation of sound tissue) and aesthetic results (disappearance of lesions) over the time. The present report evaluates the effectiveness of Icon infiltration resin on postorthodontic white spots at 6 months, 1 and 4 years.

Polyols and remineralisation of enamel subsurface lesions

Sugar-free chewing gum containing polyols has been demonstrated to reduce caries experience in randomised controlled clinical trials. A range of polyols (mannitol, sorbitol, xylitol and maltitol) can be found in sugar-free gums and it has been claimed that they can facilitate calcium uptake into enamel subsurface lesions promoting remineralisation.

OBJECTIVES

The aim of this study was to compare the effect of polyols on remineralisation of enamel subsurface lesions in vitro by artificial saliva (AS) and by AS containing the salivary biomimetic casein phosphopeptide amorphous calcium phosphate (CPP-ACP).

METHODS

The polyols (12.6% w/v) and CPP-ACP (0.376% w/v) were used at physiologically relevant concentrations approximating those released into saliva during chewing a CPP-ACP/polyol chewing gum. Enamel subsurface lesions were exposed to one of the polyols (xylitol, sorbitol, maltitol, mannitol) in AS or AS containing CPP-ACP for 7days at 37°C with a change of solution each day. Remineralisation of the enamel subsurface lesions was measured by transverse microradiography.

RESULTS

A statistical test for equivalence showed there was no difference in remineralisation between the AS solutions with or without any of the polyols. The AS+CPP-ACP solution substantially promoted remineralisation over AS alone independently of any polyol added.

CONCLUSION

This controlled in vitro study showed that polyols at physiologically relevant concentrations did not promote remineralisation of enamel subsurface lesions by facilitating calcium uptake into the lesion.

Casein Phosphopeptide-Amorphous Calcium Phosphate Reduces Streptococcus mutans Biofilm Development on Glass Ionomer Cement and Disrupts Established Biofilms

Glass ionomer cements (GIC) are dental restorative materials that are suitable for modification to help prevent dental plaque (biofilm) formation. The aim of this study was to determine the effects of incorporating casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) into a GIC on the colonisation and establishment of Streptococcus mutans biofilms and the effects of aqueous CPP-ACP on established S mutans biofilms. S. mutans biofilms were either established in flow cells before a single ten min exposure to 1% w/v CPP-ACP treatment or cultured in static wells or flow cells with either GIC or GIC containing 3% w/w CPP-ACP as the substratum. The biofilms were then visualised using confocal laser scanning microscopy after BacLight LIVE/DEAD staining. A significant decrease in biovolume and average thickness of S. mutans biofilms was observed in both static and flow cell assays when 3% CPP-ACP was incorporated into the GIC substratum. A single ten min treatment with aqueous 1% CPP-ACP resulted in a 58% decrease in biofilm biomass and thickness of established S. mutans biofilms grown in a flow cell. The treatment also significantly altered the structure of these biofilms compared with controls. The incorporation of 3% CPP-ACP into GIC significantly reduced S. mutans biofilm development indicating another potential anticariogenic mechanism of this material. Additionally aqueous CPP-ACP disrupted established S. mutans biofilms. The use of CPP-ACP containing GIC combined with regular CPP-ACP treatment may lower S. mutans challenge.

Devices for In situ Development of Non-disturbed Oral Biofilm. A Systematic Review

Objective: The aim of this review was to assess the types of devices used for in situ development of oral biofilm analyzed microbiologically.

Materials and Methods: A systematic search of the literature was conducted to identify all in situ studies of oral biofilm which used an oral device; the Ovid MEDLINE and EMBASE databases complemented with manual search were used. Specific devices used to microbiologically analyze oral biofilm in adults were included. After reading of the selected full texts, devices were identified and classified according to the oral cavity zone and manufacturing material. The “ideal” characteristics were analyzed in every group.

Results: The search provided 787 abstracts, of which 111 papers were included. The devices used in these studies were classified as palatal, lingual or buccal. The last group was sub-classified in six groups based on the material of the device. Considering the analyzed characteristics, the thermoplastic devices and the Intraoral Device of Overlaid Disk-holding Splints (IDODS) presented more advantages than limitations.

Conclusions: Buccal devices were the most commonly used for the study of in situ biofilm. The majority of buccal devices seemed to slightly affect the volunteer's comfort, the IDODS being the closest to the “ideal” model.

Clinical Relevance: New devices for in situ oral biofilm microbiological studies should take into account the possible effect of their design on the volunteer's comfort and biofilm formation.

Remineralizing potential of CPP-ACP applied for 1 min in vitro

AIM

To evaluate (1) the remineralizing potential of Tooth Mousse(®) (TM) on artificial carious lesions, when applied for 1 min, and (2) the benefit of a fluoridated dentifrice prior to TM application.

METHODS

Demineralisation caries-like lesions 120-200 μm deep were produced by placing molars in demineralizing solution for 96 h, sections 100-150 μm thick were then randomly assigned to four groups. Specimens were treated thrice daily with a non-fluoridated (Group A), or fluoridated dentifrice (1000 ppm) (Group B), or TM (Group C), or a fluoridated dentifrice followed by TM (Group D) then subjected to a 10-day pH cycling model. Lesion evaluation involved polarizing light microscopy and microradiography.

RESULTS

Application of TM in isolation (Group C) for 1 min resulted in significant increase in lesion depth (LD), however, an increase in mineral content deposition (V max) was not significant. Post treatment LD increases were greatest in Group A, then Group C and Group B respectively. A decrease in LD (by 19.9 %) was noted only after fluoridated dentifrice and TM (Group D) were applied consecutively for 1 min each (p < 0.05). Mineral content deposition was also greatest in this group (Group D) and both V max and LD changes were statistically significant when compared to other groups.

CONCLUSIONS

TM alone failed to remineralize carious lesions when applied for 1 min. However, remineralization occurred after a prior application of a fluoridated dentifrice.

Re- and Demineralization Characteristics of Enamel Depending on Baseline Mineral Loss and Lesion Depth in situ

Objectives: The aim of this double-blinded, randomized, cross-over in situ study was to evaluate the re- and demineralization characteristics of sound enamel as well as lowly and highly demineralized caries-like enamel lesions after the application of different fluoride compounds. Methods: In each of three experimental legs of 4 weeks, 21 participants wore intraoral mandibular appliances containing 4 bovine enamel specimens (2 lowly and 2 highly demineralized). Each specimen included one sound enamel and either one lowly demineralized (7 days, pH 4.95) or one highly demineralized (21 days, pH 4.95) lesion, and was positioned 1 mm below the acrylic under a plastic mesh. The three randomly allocated treatments (application only) included the following dentifrices: (1) 1,100 ppm F as NaF, (2) 1,100 ppm F as SnF2 and (3) 0 ppm F (fluoride-free) as negative control. Differences in integrated mineral loss (ΔΔZ) and lesion depth (ΔLD) were calculated between values before and after the in situ period using transversal microradiography. Results: Of the 21 participants, 6 did not complete the study and 2 were excluded due to protocol violation. Irrespectively of the treatment, higher baseline mineral loss and lesion depth led to a less pronounced change in mineral loss and lesion depth. Except for ΔΔZ of the dentifrice with 0 ppm F, sound surfaces showed significantly higher ΔΔZ and ΔLD values compared with lowly and highly demineralized lesions (p < 0.05, t test). Conclusion: Re- and demineralization characteristics of enamel depended directly on baseline mineral loss and lesion depth. Treatment groups should therefore be well balanced with respect to baseline mineral loss and lesion depth.

EFFECT OF GUM CHEWING ON AIR SWALLOWING, SALIVA SWALLOWING AND BELCHING

BACKGROUND

Eructation is a physiologic event which allows gastric venting of swallowed air and most of the time is not perceived as a symptom. This is called gastric belching. Supragastric belching occurs when swallowed air does not reach the stomach and returns by mouth a short time after swallowing. This situation may cause discomfort, life limitations and problems in daily life.

OBJECTIVE

Our objective in this investigation was to evaluate if gum chewing increases the frequency of gastric and/or supragastric belches.

METHODS

Esophageal transit of liquid and gas was evaluated by impedance measurement in 16 patients with complaint of troublesome belching and in 15 controls. The Rome III criteria were used in the diagnosis of troublesome belching. The esophageal transit of liquid and gas was measured at 5 cm, 10 cm, 15 cm and 20 cm from the lower esophageal sphincter. The subjects were evaluated for 1 hour which was divided into three 20-minute periods: (1) while sitting for a 20-minute base period; (2) after the ingestion of yogurt (200 mL, 190 kcal), in which the subjects were evaluated while chewing or not chewing gum; (3) final 20-minute period in which the subjects then inverted the task of chewing or not chewing gum. In gastric belch, the air flowed from the stomach through the esophagus in oral direction and in supragastric belch the air entered the esophagus rapidly from proximal and was expulsed almost immediately in oral direction. Air swallows were characterized by an increase of at least 50% of basal impedance and saliva swallow by a decrease of at least 50% of basal impedance, that progress from proximal to distal esophagus.

RESULTS

In base period, air swallowing was more frequent in patients than in controls and saliva swallowing was more frequent in controls than in patients. There was no difference between the medians of controls and patients in the number of gastric belches and supragastric belches. In six patients, supragastric belches were seen at least once during the 20-minute base period. None of the controls had supragastric belches. In the control group, the ingestion of yogurt caused no significant alteration in the number of air swallows, saliva swallows, gastric belches and supragastric belches. In the patient group, there was an increase in the number of air swallows. If the subjects were chewing gum during this 20-minute period, there was an increase in the number of saliva swallows in both groups, without alterations of the number of air swallow, gastric belches and supragastric belches. There was no alteration in the number of the saliva swallows, air swallows, gastric belches and supragastric belches in both groups for subjects who did not chew gum in the 20-40 minute period after yogurt ingestion. When the subjects were chewing the gum, there was an increase in saliva swallows in the control and patients groups and in air swallows in the patients group.

CONCLUSION

Gum chewing causes an increase in saliva swallowing in both patients with excessive belching and in controls, and an increase in air swallowing in patients with excessive belching 20 minutes after yogurt ingestion. Gum chewing did not increase or decrease the frequency of gastric or supragastric belches.

The effect of various model parameters on enamel caries lesions in a dose-response model in situ

OBJECTIVES

The aim of this exploratory double-blinded, randomized, cross-over, in situ study was to compare the effects of various model parameters ('intervention', 'brushing', 'position') on enamel caries lesions in a dose-response model.

METHODS

In each of four experimental legs of four weeks 16 participants wore intraoral mandibular appliances with four 'plaque-retaining' and four 'easily cleanable' positioned pre-demineralized bovine enamel specimens in the vestibular flanges mimicking proximal and buccal surfaces, respectively (n=512). The four randomly allocated interventions (either application only or brushing) included the following dentifrices: AlF3 1360ppmF(-)+chlorhexidine 0.05% (Lacalut aktiv, LA1360), NaF 1,450ppmF(-)(Blend-a-Med ProExpert), NaF 500ppm F(-) and 0ppm F(-) as negative control (NC) (both experimental, based on Blend-a-Med ProExpert).

RESULTS

Differences in integrated mineral loss (ΔΔZ) and lesion depth (ΔLD) were calculated between values before and after the in situ period using transversal microradiography. Significant differences for ΔΔZ [adjusted mean (95% CI))] were found between NC, NaF500 and LA1360for both 'plaque-retaining' [-1830 (-2371;1289); -986 (-1530;442); -2 (-548;544)vol%×μm] as well as 'easily cleanable' specimens [-399 (-682; -116); -391 (-672; -110); -16 (-302;270)vol%×μm]. Values for NaF1450 revealed a similar dose-response as LA1360.Values for LA1360 and NaF1450 did not differ significantly (p>0.05; ANCOVA).

CONCLUSION/CLINICAL SIGNIFICANCE

The design of the present in situ study was able to reveal a fluoride dose-response to hamper further demineralization of enamel specimens for 'easily cleanable' and 'plaque-retaining' sites being brushed or not. Particularly 'plaque-retaining' sites seem to be recommendable for measuring potential anticaries efficacy in situ.

Resin infiltration of non-cavitated caries lesions: a systematic review

OBJECTIVE

The aim of this systematic review was to evaluate the in vivo scientific evidence of the ability of resin infiltration (RI) to arrest non-cavitated caries lesions.

MATERIALS AND METHODS

The PubMed database was searched for randomized controlled trials that evaluated the in vivo effect of RI versus placebo or other preventive treatment on the progression of caries lesions. The keywords used were 'resin infiltration, dental caries', 'resin infiltration, carious lesions', 'resin infiltration, caries lesions', 'caries infiltration' and 'Icon DMG' with the 'clinical trial' filter activated. Among the 14 articles originally identified with these keywords, only 4 (related to 3 different in vivo studies) were included for this review.

RESULTS

All 4 articles reported on proximal caries lesions. One study had been conducted on 48 high-caries-risk children while the other 3 (n = 22, 22 and 39, respectively) concerned moderate- and low-caries-risk adolescents and adults. The quality of the studies was assessed to be high with respect to randomization, split-mouth design and blinding. All the included studies showed significant differences in caries progression between test and control/placebo groups, indicating that RI may inhibit the carious process.

CONCLUSION

This systematic review revealed that RI appeared to be an effective method to arrest the progression of non-cavitated caries lesions. Additional, long-term studies are required.

Remineralizing efficacy of a CPP-ACP cream on enamel caries lesions in situ

The aim of this double-blind, randomized, cross-over in situ study was to compare the remineralizing effects induced by the application of casein phosphopeptide-stabilized amorphous calcium phosphate complexes (CPP-ACP)-containing cream (without fluoride) after the use of fluoride toothpaste with the prolonged use of fluoride toothpaste on enamel caries lesions in situ. During each of three experimental legs of 4 weeks, 13 participants wore intra-oral mandibular appliances with 8 pre-demineralized bovine enamel specimens in the vestibular flanges mimicking either 'easily cleanable' or 'proximal' surfaces (n = 312). The three randomly allocated treatments were as follows: (1) application of CPP-ACP-containing cream (GC Tooth Mouse, non-fluoride) after the use of fluoride toothpaste (1,400 ppm NaF; TM), (2) prolonged application of fluoride toothpaste (1,400 ppm NaF; positive control, PC) and (3) prolonged application of fluoride-free toothpaste (negative control, NC). Additionally, one of each of the two flanges was brushed twice daily with the respective toothpaste. The differences in integrated mineral loss as assessed by transversal microradiography were calculated between values before and after the in situ period. Changes in mineral loss were analysed for those pairs of subgroups differing in only one of the three factors (intervention, brushing and position). The PC treatment induced a significantly higher mineral gain compared with the TM and NC treatments. No significant differences between TM and NC for both positions were observed. In conclusion, the additional use of a CPP-ACP-containing cream seems to be less efficacious in remineralizing caries lesions than the prolonged application of fluoride toothpaste.

In situ effect of a commercial CPP-ACP chewing gum on the human enamel initial erosion

OBJECTIVE

This study evaluated the in situ rehardening effect of a commercial chewing gum containing casein phosphopeptide - amorphous calcium phosphate (CPP-ACP) on initial erosion lesions.

METHODS

Seventy-two human enamel blocks, after selection (initial surface hardness - SHi) and in vitro short-term acidic exposure (cola drink for 3 min - SHd) were randomly assigned to three groups. The factors under study were treatment (3 levels: GI chewing gum with CPP-ACP, GII chewing gum without CPP-ACP and GIII control group without gum) and intraoral period (2 levels: 2 and 24h). Twelve volunteers wore intraoral palatal devices for 24h in 3 crossover phases. On each phase, after 2h the surface hardness was assessed (SHf1) and the blocks were reinserted and the devices were used for additional 22 h (SHf2). In phases of GI and GII volunteers chewed the respective gum during 30 min, for 4 times with an interval of 4h. Percentage of surface hardness recovery (%SHR) was calculated after 2 and 24 h. The data were analysed by repeated measures ANOVA and Tukey's test.

RESULTS

Chewing gum with CPP-ACP (2h=50.0%<24h=95.9%) showed higher hardness recovery than chewing gum without CPP-ACP (2h=30.0%<24 h=71.1%) and control (2 h=15.7%<24 h=40.9%) (p<0.05).

CONCLUSIONS

The results suggest that saliva increased hardness of softened enamel after the use of conventional chewing gum (GII) and this effect was enhanced by the prolonged intraoral period (24 h) and by the use of CPP-ACP chewing gum (GI).

CLINICAL SIGNIFICANCE

Since chewing gum is an alternative to enhance salivary defenses after erosive challenges, CPP-ACP chewing gum might be a supplementary strategy to potentiate the mineral precipitation of initial erosion lesions.

In situ protocol for the determination of dose-response effect of low-fluoride dentifrices on enamel remineralization

No in situ protocol has assessed the dose-response effects of fluoride dentifrices involving low-fluoride formulations.

The contemporary approach to tooth preservation: minimum intervention (MI) caries management in general practice

The minimum intervention (MI) approach summarises a clinical, evidence-based rationale for the preventive and cause-related approach to oral diseases in general and to caries in particular. MI oral care with respect to the management of patients suffering from dental caries is a concept based on an updated understanding of the histopathological carious process as well as the development of diagnostic technologies and adhesive, bioactive restorative materials. A patient-centred MI care plan for use in general dental practice is described, detailing the four phases of identifying disease, controlling/preventing disease, refurbishing/repairing tooth surfaces/restorations and recall consultations.

Calcium phosphopeptides -- mechanisms of action and evidence for clinical efficacy

Phosphoproteins/phosphopeptides with clusters of acidic residues are found throughout nature, where they aid in the prevention of unwanted precipitation of solid calcium phosphates. The acidic residues, particularly phosphoserine, interact with calcium and stabilize clusters of calcium and phosphate. Saliva and milk are two examples of biological fluids that contain such phosphoprotein/phosphopeptide-stabilized calcium phosphates, and both share a similar evolutionary pathway. Saliva has been shown to have remineralization potential and is of critical importance in maintaining the mineral content of teeth in the oral environment. Milk can be enzymatically modified to release casein phosphopeptides that contain the clusters of residues that allow milk to stabilize high concentrations of calcium and phosphate. These casein phosphopeptide-stabilized amorphous calcium phosphate nanocomplexes (CPP-ACP) can stabilize even higher concentrations of calcium and phosphate than milk and can be considered a salivary biomimetic, since they share many similarities to statherin. The mechanisms of action and the growing body of scientific evidence that supports the use of CPP-ACP to augment fluoride in inhibiting demineralization and enhancing the remineralization of white-spot lesions are reviewed.

Remineralization Models

During the ICNARA 2 conference, a workshop was held on remineralization models. The group considered the role of remineralization models, whether there was one ideal in situ model design, what essential features should be incorporated into an in situ model, other alternative models, and what new methods for measuring remineralization were on the horizon. This paper summarizes the discussion. In situ and other caries models can be used as a surrogate for caries clinical trials but only when data exist to validate the model. In situ model design should be flexible to allow for investigation of different aspects of the caries process; however, several essential features were identified that should be incorporated into the study design. A range of other caries models was discussed, including the study of non-cavitated lesions, lesions post-orthodontic therapy, plaque retention models to form more standardized lesions, and the study of root caries lesions. Numerous new methods for quantifying remineralization were discussed, but it was considered that these require validation before they can be used in clinical trials.