The Anticaries Efficacy of a 1.5% Arginine and Fluoride Toothpaste.

Dental caries remains a world-wide disease despite the global distribution of fluoride. It has become apparent that the introduction of significant levels of sugar (fermentable carbohydrate) into the diet has resulted in a change in the biofilm, encouraging acid formation. Further, there has been a shift in the microbiota in the biofilm to a flora that produces acid, and thrives and reproduces in an acidic environment. The management of caries activity under these conditions has focused on brushing to remove the biofilm with fluoride pastes, and high-dose fluoride treatments. Kleinberg, in the 1970s, identified an arginine-containing compound in saliva that several oral biofilm bacterial species metabolize to produce base. Multiple in situ and in vivo studies have been conducted, and have discussed the ability of multiple bacteria to increase the resting pH of the biofilm and even reduce the decrease in pH when the biofilm is challenged with glucose. This shift in resting pH can shift the level of caries formation by the biofilm. Here, we present 8 clinical studies, with different clinical designs, measuring different clinical outcomes, for a diverse, world-wide population. Each of these studies demonstrates reductions in caries formation beyond that seen with fluoride alone and several demonstrate the reversal of early caries lesions. Significant clinical research has been shown that 1.5% arginine combined with fluoride toothpaste has superior anti-caries efficacy to toothpaste containing fluoride alone.

Mechanisms Linking Interparental Aggression to Child Dental Caries.

Research has garnered support for a systemic view of factors affecting child dental caries that accounts for the influence of social factors such as the family environment. Our previous work has demonstrated the association between mother-to-father emotional aggression and child caries. The present study builds on these results by evaluating pathways that might explain this relation. Families (n = 135) completed a multimethod assessment of mother-to-father emotional aggression, child caries, and several hypothesized mediators (i.e., child cariogenic snack and drink intake, child internalizing behaviors, child salivary cortisol and α-amylase reactivity, parental laxness, child oral hygiene maintenance, and parental socialization of child oral hygiene maintenance). Mediation analyses partially supported the role of the child's diet as a mechanism linking mother-to-father emotional aggression and child caries. However, children's neglect of oral hygiene, parental laxness, and child emotional and biological disturbances failed to stand as conduits for this association. Future investigations should expand upon these results to better establish the causal links that could only be suggested by the present cross-sectional findings.

HOCl Rapidly Kills Corona, Flu, and Herpes to Prevent Aerosol Spread.

The COVID-19 pandemic has escalated the risk of SARS-CoV-2 transmission in the dental practice, especially as droplet-aerosol particles are generated by high-speed instruments. This has heightened awareness of other orally transmitted viruses, including influenza and herpes simplex virus 1 (HSV1), which are capable of threatening life and impairing health. While current disinfection procedures commonly use surface wipe-downs to reduce viral transmission, they are not fully effective. Consequently, this provides the opportunity for a spectrum of emitted viruses to reside airborne for hours and upon surfaces for days. The objective of this study was to develop an experimental platform to identify a safe and effective virucide with the ability to rapidly destroy oral viruses transported within droplets and aerosols. Our test method employed mixing viruses and virucides in a fine-mist bottle atomizer to mimic the generation of oral droplet-aerosols. The results revealed that human betacoronavirus OC43 (related to SARS-CoV-2), human influenza virus (H1N1), and HSV1 from atomizer-produced droplet-aerosols were each fully destroyed by only 100 ppm of hypochlorous acid (HOCl) within 30 s, which was the shortest time point of exposure to the virucide. Importantly, 100 ppm HOCl introduced into the oral cavity is known to be safe for humans. In conclusion, this frontline approach establishes the potential of using 100 ppm HOCl in waterlines to continuously irrigate the oral cavity during dental procedures to expeditiously destroy harmful viruses transmitted within aerosols and droplets to protect practitioners, staff, and other patients.

Effect of an 8.0% arginine and calcium carbonate desensitizing toothpaste on shear dentin bond strength.

OBJECTIVE: The objective of this study was to determine the effect of an 8.0% arginine and calcium carbonate desensitizing toothpaste (Colgate Sensitive Pro-Relief) on shear bond strength of composites to bovine incisor dentin. METHODS: Bovine incisors were sectioned and prepared into 27 dentin specimens. The experimental group had 13 specimens treated for 10 sessions of two-minute brushing with an 8.0% arginine and calcium carbonate desensitizing toothpaste, followed by a 30-second agitated water wash. The control group had 14 specimens treated with flour of pumice only. Each specimen was dried, etched with 35% phosphoric acid for 15 seconds, and washed clean. A bonding agent was applied and polymerized. A 2.38 mm diameter column of Filtek Supreme A2 was bonded to the surface and polymerized as per manufacturer's instructions. Specimens were stored in water for at least 48 hours, subjected to a shear force at a crosshead speed of 0.5 mm/minute on an Instron mechanical testing device, and force at failure was recorded. A one-sided t-test was used to evaluate significant differences among the groups as measured by mean shear strength. RESULTS: Mean shear force was 19.6 +/- 9.4 (SD) for the experimental group and 15.4 +/- 6.0 for the control group with p = 0.0291. CONCLUSION: No significant differences were found for bond strength to dentin treated with an 8.0% arginine and calcium carbonate desensitizing toothpaste or pumice. Dentists can still achieve optimal dentin bonding results if a patient is using Colgate Sensitive Pro-Relief to manage dentin hypersensitivity.

COVID-19 Vaccination: To Lead by Example or an Opportunity Lost.

Coronavirus disease 2019 (COVID-19) has created a global health emergency. Vaccine hesitancy and tremendous misinformation about the actual science are leaving the public with significant confusion. However, sound epidemiologic science is guiding us to a clear path toward mitigating this modern-day scourge. It is remarkable how putting an end to current COVID-19 outbreaks has such a simple solution-convincing the public to accept getting vaccinated. The dental research, dental education, and dental practice communities have a unique opportunity to act as trusted public exemplars as well as trusted interpreters of the science for the public.

Chewing variation in lepidosaurs and primates.

Mammals chew more rhythmically than lepidosaurs. The research presented here evaluated possible reasons for this difference in relation to differences between lepidosaurs and mammals in sensorimotor systems. Variance in the absolute and relative durations of the phases of the gape cycle was calculated from kinematic data from four species of primates and eight species of lepidosaurs. The primates exhibit less variance in the duration of the gape cycle than in the durations of the four phases making up the gape cycle. This suggests that increases in the durations of some gape cycle phases are accompanied by decreases in others. Similar effects are much less pronounced in the lepidosaurs. In addition, the primates show isometric changes in gape cycle phase durations, i.e. the relative durations of the phases of the gape cycle change little with increasing cycle time. In contrast, in the lepidosaurs variance in total gape cycle duration is associated with increases in the proportion of the cycle made up by the slow open phase. We hypothesize that in mammals the central nervous system includes a representation of the optimal chew cycle duration maintained using afferent feedback about the ongoing state of the chew cycle. The differences between lepidosaurs and primates do not lie in the nature of the sensory information collected and its feedback to the feeding system, but rather the processing of that information by the CNS and its use feed-forward for modulating jaw movements and gape cycle phase durations during chewing.

Nonrestorative Treatments for Caries: Systematic Review and Network Meta-analysis.

The goal of nonrestorative or non- and microinvasive caries treatment (fluoride- and nonfluoride-based interventions) is to manage the caries disease process at a lesion level and minimize the loss of sound tooth structure. The purpose of this systematic review and network meta-analysis was to summarize the available evidence on nonrestorative treatments for the outcomes of 1) arrest or reversal of noncavitated and cavitated carious lesions on primary and permanent teeth and 2) adverse events. We included parallel and split-mouth randomized controlled trials where patients were followed for any length of time. Studies were identified with MEDLINE and Embase via Ovid, Cochrane CENTRAL, and Cochrane Database of Systematic Reviews. Pairs of reviewers independently conducted the selection of studies, data extraction, risk-of-bias assessments, and assessment of the certainty in the evidence with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Data were synthesized with a random effects model and a frequentist approach. Forty-four trials (48 reports) were eligible, which included 7,378 participants and assessed the effect of 22 interventions in arresting or reversing noncavitated or cavitated carious lesions. Four network meta-analyses suggested that sealants + 5% sodium fluoride (NaF) varnish, resin infiltration + 5% NaF varnish, and 5,000-ppm F (1.1% NaF) toothpaste or gel were the most effective for arresting or reversing noncavitated occlusal, approximal, and noncavitated and cavitated root carious lesions on primary and/or permanent teeth, respectively (low- to moderate-certainty evidence). Study-level data indicated that 5% NaF varnish was the most effective for arresting or reversing noncavitated facial/lingual carious lesions (low certainty) and that 38% silver diamine fluoride solution applied biannually was the most effective for arresting advanced cavitated carious lesions on any coronal surface (moderate to high certainty). Preventing the onset of caries is the ultimate goal of a caries management plan. However, if the disease is present, there is a variety of effective interventions to treat carious lesions nonrestoratively.

Evidence for existence in human tissues of monomers for plastics and rubber manufacture.

Although exposure to many industrially important monomers is controlled by law, few of these reactive chemicals have been determined in human tissues. Analogy with other fat-soluble organic substances strongly implies that these monomers may be retained in tissue, subject to the usual physiological constraints of metabolism, solubility and volatility. The storage of DDT and PCBs is discussed, as well as tetrachloro-ethylene (PCE) and trichloroethylene (TCE), which are chemically similar to many industrially used monomers. Styrene in blood and breath and its metabolites in urine have been studied in humans. Styrene and vinyl chloride have been measured in fat tissue of polymerization workers.

Pesticides and inner-city children: exposures, risks, and prevention.

Six million children live in poverty in America's inner cities. These children are at high risk of exposure to pesticides that are used extensively in urban schools, homes, and day-care centers for control of roaches, rats, and other vermin. The organophosphate insecticide chlorpyrifos and certain pyrethroids are the registered pesticides most heavily applied in cities. Illegal street pesticides are also in use, including tres pasitos (a carbamate), tiza china, and methyl parathion. In New York State in 1997, the heaviest use of pesticides in all counties statewide was in the urban boroughs of Manhattan and Brooklyn. Children are highly vulnerable to pesticides. Because of their play close to the ground, their hand-to-mouth behavior, and their unique dietary patterns, children absorb more pesticides from their environment than adults. The long persistence of semivolatile pesticides such as chlorpyrifos on rugs, furniture, stuffed toys, and other absorbent surfaces within closed apartments further enhances urban children's exposures. Compounding these risks of heavy exposures are children's decreased ability to detoxify and excrete pesticides and the rapid growth, development, and differentiation of their vital organ systems. These developmental immaturities create early windows of great vulnerability. Recent experimental data suggest, for example, that chlorpyrifos may be a developmental neurotoxicant and that exposure in utero may cause biochemical and functional aberrations in fetal neurons as well as deficits in the number of neurons. Certain pyrethroids exert hormonal activity that may alter early neurologic and reproductive development. Assays currently used for assessment of the toxicity of pesticides are insensitive and cannot accurately predict effects to children exposed in utero or in early postnatal life. Protection of American children, and particularly of inner-city children, against the developmental hazards of pesticides requires a comprehensive strategy that monitors patterns of pesticide use on a continuing basis, assesses children's actual exposures to pesticides, uses state-of-the-art developmental toxicity testing, and establishes societal targets for reduction of pesticide use.

The effect of ammonium glycopyrrolate (Robinul)-induced xerostomia on oral mucosal wetness and flow of gingival crevicular fluid in humans.

The antisialogogue, ammonium glycopyrrolate (Robinul), was used to reduce the salivary flow rate in healthy individuals with normal salivary function to determine whether the dry-mouth symptoms and reduced amounts and patterns of oral mucosal wetness found previously in hyposalivators could be induced by this means. After baseline measurements, the drug was given to 10 healthy volunteers and their resting whole-saliva flow rate was measured at 0, 15, 60, 105 and 150 min thereafter. At the same times, the thickness of the layer of residual mucosal saliva (a measure of residual mucosal wetness) at each of 22 intraoral sites was also determined. The saliva flow rate fell from a mean of 0.45 +/- 0.07 ml/min to a mean of 0.05 +/- 0.02 ml/mm by 1 h and slowly thereafter to a mean of 0.02 +/- 0.01 to 0.03 +/- 0.01 ml/min for the remainder of the experiment. Onset of dryness symptoms was observed approx. 30 min after giving the drug. Simultaneously, the residual saliva at each of the 22 sites teted decreased to a thickness level previously found in patients with hyposalivation and who exhibited an intense feeling of dry mouth. Despite these decreases in thickness, the pattern of residual mucosal wetness throughout the mouth remained more or less unchanged. As in earlier studies, wetness was least on the hard palate and highest on the posterior dorsum of the tongue. An altered taste of the residual saliva in the mouth and an increased feeling of roughness as the tongue was passed over labial and buccal mucosal surfaces were noted. The amount of gingival crevicular fluid (GCF) in 12 gingival sites in each of the participants was also measured. Unlike the reduction in salivary flow, changes in GCF over the 150 min of the study were negligible. From this it was concluded that GCF could contribute much more to the oral fluids in dry-mouth than in normal individuals, especially when there is greater gingival inflammation.

Health status of styrene-polystyrene polymerization workers.

Styrene monomer is a greatly used chemical, chiefly in the production of polystyrene. A cross-sectional health survey of 493 production workers was undertaken at the oldest and largest monomer production, polymerization, and extrusion facility in the United States. Relative exposure durations and levels were obtained from occupational histories and corroborated by spot air sampling, blood and fat styrene concentrations and levels of urinary mandelic and phenylglyoxylic acids. Statistically significant differences between the prevalence of abnormalities in high and low exposure groups were found for the following: history of acute prenarcotic symptoms, history of acute lower respiratory symptoms, peroneal nerve conduction velocities, relative lymphocytosis, and elevated gamma glutamyl transpetsidase. The following showed no distinct pattern in prevalence when analyzed by exposure group: chest radiographic changes; indices or restrictive, obstructive and small airway dysfunction; other hepatic and hematological parameters; carcinoembryonic antigen level; sputum cytopathology; radial nerve conduction velocities; and ophthalmological findings. Clinically significant abnormalities were rare.

Analgesic efficacy and safety of an intraoral lidocaine patch.

The effectiveness of intraoral II-docaine patches was tested by asking participants to rate the pain experienced after insertions of a 25-gauge needle. Needlesticks were performed at baseline and at various time points after patch placement. Each needlestick included contact with the periosteum. Lidocaine patches achieved significantly better analgesia than the placebo within 2.5 to five minutes after placement. Drug-related side effects were minimal and venous blood levels of lidocaine were low, averaging 10 to 14 times less than those achieved with a typical injection of lidocaine plus epinephrine. The authors conclude that the lidocaine patches used in this study are effective and safe in reducing needle insertion pain in adults.

Role of saliva in oral dryness, oral feel and oral malodour.

Patients who believe they have oral malodour often have a dry mouth condition instead. Here we have examined its relation to oral malodour, real or perceived. A direct relationship between the thickness of the film of residual saliva on mucosal surfaces throughout the mouth and perception of a dry mouth was observed. On the hard palate, the thickness of this film proved to be diagnostic for a dry mouth and corresponded to lower resting saliva flow and pH levels (P< 0.001). Intra-muscular administration of the anti-sialogogue, Robinul, accurately produced the dry mouth condition. Using a sulphide monitor, loss of volatile sulphur compounds into mouth air progressively occurred as the mouth became drier. Mouth pH and Eh on the dorsum of the tongue correspondingly fell. Mouth breathing led to tongue and palate moisture loss thus enabling escape of malodour volatiles into mouth air. Measurement of oral dryness should make it possible to differentiate genuine malodour from dry mouth related pseudo-malodour subjects, and in turn, the latter from patients that are halitophobic. This should facilitate identification of such patients and avoid error in their clinical management.

Preventive resin restorations: indications, technique, and success.

Although preventive resin restorations have been reported since 1977, there is little uniformity concerning the indications for this procedure, nor is there a standard technique. This article proposes diagnostic criteria for pit and fissure occlusal caries and diagnosis-related considerations for treatment planning for preventive resin restorations. A step-by-step "laminate" technique, which includes, successively, a glass-ionomer cement liner, a posterior composite resin, and a sealant, is described. The success rates reported for several clinical studies of preventive resin restorations are presented, although the criteria for this restoration, treatment methodology, and the determinates of success vary from study to study.

An evaluation of intraoral lidocaine patches in reducing needle-insertion pain.

Intraoral lidocaine patches have recently been approved by the US Food and Drug Administration for the production of topical anesthesia before superficial dental procedures and for the reduction of pain associated with local anesthetic injections. The results of this 5-center clinical study showed that lidocaine patches were significantly more efficacious than matching placebo patches in reducing the pain associated with 25-gauge needle insertions to the level of bone in the maxillary premolar region. Anesthetic onset occurred within 5 minutes and was present for the entire 15-minute period that the patches were in contact with the oral mucosa. In addition, the patches were safe and well tolerated by study participants. Other potential clinical applications of this novel delivery system are also discussed in this article.

Clinical evaluation of the effect of a remineralizing toothpaste on dentinal sensitivity.

Dentinal hypersensitivity is a common dental problem without a satisfactory solution. Most therapies have focused on either trying to block the stimulation of dentinal nerves or on sealing open dentinal tubules. This study evaluated, in a double blind clinical trial, the effect of Enamelon, a dentifrice containing sodium fluoride, calcium salts and phosphate salts (calcium separated from the phosphate and fluoride by a plastic divider in the tube to prevent interaction) on dentinal hypersensitivity over an 8-week period. A conventional OTC dentifrice containing NaF without calcium and phosphate enhancement served as the control. A third dentifrice, containing sodium monofluorophosphate enhanced by calcium and phosphate salts, was also tested. Based upon subjective anecdotal information, net numbers of sensitive teeth which became non-sensitive, and a logit analysis of the change in the proportion of sensitive teeth over the study time period, Enamelon was the most effective product, and the OTC control the least effective.

The effect of powder/liquid ratio on the in vivo solubility of polycarboxylate cement.

A clinical study of the solubility of three powder/liquid ratios of polycarboxylate cement demonstrated a threefold increase in the solubility for the lower powder/liquid ratios. The three liquid/powder ratios tested were within the range recommended by the manufacturer. The data suggest that the higher powder/liquid ratio (1.5:1) is preferable when minimal solubility is a primary requirement.