Deforestation reduces rainfall by 74% and increases temperatures by 16% in the Amazon during the dry season, study says

For the first time, research led by scientists at the University of São Paulo quantifies the impact of forest loss and global climate change on the biome.

Fundação de Amparo à Pesquisa do Estado de São Paulo

LinkedInWeChatBlueskyMessageWhatsAppEmail

 

image: 

For the first time, research led by scientists at the University of São Paulo quantifies the impact of forest loss and global climate change on the biome.

view more 

Credit: Luiz Augusto Toledo Machado (IF-USP

Deforestation in the Brazilian Amazon is responsible for approximately 74.5% of the reduction in rainfall and 16.5% of the temperature increase in the biome during the dry season. For the first time, researchers have quantified the impact of vegetation loss and global climate change on the forest.

A study led by scientists from the University of São Paulo (USP) in Brazil provides fundamental results to guide effective mitigation and adaptation strategies. These are the target themes of the United Nations Climate Conference (COP30), which is scheduled for November in the Amazonian metropolis of Belém, in the state of Pará, Brazil. The results of the study are included in the latest issue of Nature Communications and will be featured on its cover.

Using parametric statistical models, they unraveled the effects of forest loss and changes in temperature, precipitation, and greenhouse gas mixing rates.

Rainfall decreased by approximately 21 mm per year during the dry season, with deforestation contributing to a 15.8 mm decrease. The maximum temperature increased by about 2.0 °C, of which 16.5% was attributed to forest loss and the remainder to global climate change.

“Several scientific articles on the Amazon have already shown that the temperature is higher, that rainfall has decreased, and that the dry season has increased, but there was still no separation between the effect of climate change, caused mainly by pollution from countries in the Northern Hemisphere, and deforestation caused by Brazil itself. Through this study, we were able to separate and weigh each of these components, practically showing a kind of ‘account payable,’” summarizes Professor Luiz Augusto Toledo Machado.

Machado, a researcher at the University of São Paulo’s Physics Institute (IF-USP) and a collaborator at the Max Planck Institute’s Department of Chemistry in Germany, tells Agência FAPESP that the results underscore the importance of preserving standing forests to maintain climate resilience.

Research has shown that the impact of deforestation is most intense in the early stages. The greatest changes in the local climate occur when 10% to 40% of the forest is lost.

“The effects of the changes, especially in temperature and precipitation, are much more significant in the first few percent of deforestation. In other words, we have to preserve the forest; that’s very clear. We can’t transform it into something else, such as pastureland. If there’s any type of exploitation, it needs to be sustainable,” adds Professor Marco Aurélio Franco, from the Institute of Astronomy, Geophysics, and Atmospheric Sciences (IAG) at USP.

Franco is the first author of the article and received a postdoctoral fellowship from FAPESP, which also supported the work through another grant (21/12954-5) from the Research Center for Greenhouse Gas Innovation (20/15230–5) and the Research Program on Global Climate Change – RPGCC (22/07974-0).

The project supported by the RPGCC is being developed in partnership with the Chinese Academy of Sciences. One of the overseas leaders and authors of the work is researcher Xiyan Xu.

Sensitive ecosystem balance

As the largest and most biodiverse tropical forest in the world, the Amazon plays an important role in regulating the global climate. For example, it is responsible for the so-called “flying rivers” – invisible waterways that circulate through the atmosphere and supply other biomes, such as the Brazilian savanna-like biome, known as the Cerrado. Trees draw water from the soil through their roots, transport it to their leaves, and release it into the atmosphere as vapor.

At the end of last year, an international group of researchers, including Machado and Professor Paulo Artaxo, also from the USP Physics Institute, published a study in Nature. The study showed the physical-chemical mechanism that explains the complex system of rain formation in the biome for the first time. This mechanism involves the production of aerosol nanoparticles, electrical discharges, and chemical reactions at high altitudes between night and day. The result is a kind of aerosol “machine” that produces clouds (read more at https://agencia.fapesp.br/54089).

However, deforestation and forest degradation contribute to altering this rainfall cycle, intensifying the dry season locally and increasing forest fire periods. According to data from MapBiomas, a collaborative network formed by non-governmental organizations, universities, and technology startups that maps land cover and land use in Brazil, the Brazilian Amazon lost 14% of its native vegetation between 1985 and 2023, reaching an area of 553,000 km² – equivalent to the territory of France. Pasture conversion was the main cause during this period. Despite deforestation reaching its second lowest level between August 2024 and July 2025 – an area of 4,495 km² – containing degradation, especially that caused by fire, remains challenging.

The dry season, which occurs between June and November, is when the effects of deforestation are most noticeable, particularly on rainfall. The cumulative effects further intensify seasonality.

Unraveling the data

To reach their conclusions, the scientists used parametric surface equations that considered both annual variations and deforestation. These equations enabled them to distinguish the unique contributions of global climate change and vegetation loss. They also used remote sensing data sets and long-term reanalyses, including land use classifications produced by MapBiomas.

In addition to analyzing data related to rainfall and temperature, the group examined greenhouse gas data. They concluded that the increase in carbon dioxide (CO₂) and methane (CH₄) levels over the 35-year period was driven almost entirely by global emissions (more than 99%). They observed an increase of approximately 87 parts per million (ppm) for CO₂ and about 167 parts per billion (ppb) for CH₄.

“At first, this result seemed to contradict other articles that show the impact of deforestation on reducing the forest’s ability to remove CO₂ from the atmosphere. But that’s not because CO₂ concentration is something on a large scale. Those were local measurements of CO₂ flux. When it comes to concentration, the increase is predominantly due to global emissions,” adds Machado.

The researchers warn in the article that if deforestation continues unchecked, then extrapolation of the results suggests a further decline in total precipitation during the dry season and an even greater rise in temperature.

Recent studies indicate that deforestation in the Amazon is altering South American monsoon patterns, which bring abundant rainfall to central and southeastern Brazil during the summer. These altered patterns result in drier conditions that could compromise the long-term resilience of the forest. Extreme events, such as the 2023 and 2024 droughts, only exacerbate the situation.

About São Paulo Research Foundation (FAPESP)
The São Paulo Research Foundation (FAPESP) is a public institution with the mission of supporting scientific research in all fields of knowledge by awarding scholarships, fellowships and grants to investigators linked with higher education and research institutions in the State of São Paulo, Brazil. FAPESP is aware that the very best research can only be done by working with the best researchers internationally. Therefore, it has established partnerships with funding agencies, higher education, private companies, and research organizations in other countries known for the quality of their research and has been encouraging scientists funded by its grants to further develop their international collaboration. You can learn more about FAPESP at www.fapesp.br/en and visit FAPESP news agency at www.agencia.fapesp.br/en to keep updated with the latest scientific breakthroughs FAPESP helps achieve through its many programs, awards and research centers. You may also subscribe to FAPESP news agency at http://agencia.fapesp.br/subscribe. 

---

Journal

Nature Communications

DOI

10.1038/s41467-025-63156-0 

Article Title

How climate change and deforestation interact in the transformation of the Amazon rainforest

Article Publication Date

2-Sep-2025

 

Nature Microbiology | Unlocking how bacteria bounce back after antibiotics

LinkedIn
MessageWhatsAppEmail

Peking University, September 2, 2025: A groundbreaking study by researchers from Wuhan University, York University (UK), and Peking University has uncovered how Escherichia coli (E. coli) persister bacteria survive antibiotics by protecting their genetic instructions. The work, published in Nature Microbiology, offers new hope for tackling chronic, recurring infections.

Persister bacteria, which enter a dormant state to survive antibiotics that target active cells, are linked to over 20% of chronic infections and resist current treatments. Understanding their survival mechanisms could lead to new ways to combat recurring infections. This study utilized E. coli bacteria as a model and found that prolonged stress leads to the increased formation of aggresomes (membraneless droplets) and the enrichment of mRNA (molecules that carry instructions for making proteins) within them, which enhances the ability of E. coli to survive and recover from stress.

Key Findings
They used multiple approaches, including imaging, modelling, and transcriptomics, to show that prolonged stress leading to ATP(fuel for all living cells) depletion in Escherichia coli results in increased aggresome formation, their compaction, and enrichment of mRNA within aggresomes compared to the cytosol(the liquid inside of cells). Transcript length was longer in aggresomes compared to the cytosol. Mass spectrometry showed exclusion of mRNA ribonuclease(an enzyme that breaks down RNA) from aggresomes, which was due to negative charge repulsion. Experiments with fluorescent reporters and disruption of aggresome formation showed that mRNA storage within aggresomes promoted translation and was associated with reduced lag phases during growth after stress removal. These findings suggest that mRNA storage within aggresomes confers an advantage for bacterial survival and recovery from stress.

Future Implications
This breakthrough illuminates how persister cells survive and revive after antibiotic treatment. By targeting aggresomes, new drugs could disrupt this protective mechanism, preventing bacteria from storing mRNA and making them more vulnerable to elimination, thus reducing the risk of infection relapse.

*This article is featured in PKU News "Why It Matters" series. More from this series.
Read more: https://www.nature.com/articles/s41564-025-02086-5

Written by: Akaash Babar
Edited by: Zhang Jiang

---

Journal

Nature Microbiology

 

A tomato line that’s ripe for the picking

US Department of Agriculture - Agricultural Research Service

Facebook

XLinkedInWeChatBlueskyMessageWhatsApp\Email

 

image: 

Tomato infected by tomato brown rugose fruit virus with brown rugose on fruits (top) and mottle mosaic on leaves (bottom). 

view more 

Credit: Kai Ling, USDA Agricultural Research Service

Researchers from USDA’s Agricultural Research Service (ARS) and their university partners are helping U.S. tomato growers fight a devastating crop disease. Researchers found that a tomato line developed 30 years ago is showing good resistance to the emerging tomato brown rugose fruit virus (ToBRFV), a virus that has the potential to cause billions of dollars in damage to the tomato industry in the United States and worldwide. 

ToBRFV infects tomato, pepper, and similar crops by distorting leaves and discoloring fruit, resulting in yield loss. The virus is seed-borne and overcomes the resistance genes in current commercial cultivars. It can easily spread when healthy plants come in contact with contaminated equipment, hands, clothing, or infected plants or plant parts. The most effective way for farmers and growers to manage the virus is through prevention of contact with the virus, including cleaning, sanitizing, disinfecting, and maintaining clean growing areas.

“To minimize the impact of ToBRFV, it is crucial to identify new sources of genetic resistance that can be used to breed virus-resistant tomato cultivars,” said Kai Ling, an ARS research plant pathologist at the U.S. Vegetable Laboratory in Charleston, SC. “While prevention is important, deploying cultivars with resistance genes is the criticalstrategy to combat tobamoviruses.”

 According to a recent study published in Plant Biotechnology Journal, Ling and his research team found that a tomato line (tomatoNN) expressing the tobacco N gene that was developed in the 1990s shows resistance to ToBRFV. The tomatoNN line was created by ARS plant molecular geneticist Barbara Baker and her colleagues at the Plant Gene Expression Center in Albany, CA. 

She and her team isolated the N gene from a wild tobacco relative that confers resistance to the tobacco mosaic virus (TMV) and developed the TMV-resistant tomatoNN line. 

Ling and his colleagues discovered that the tomatoNN line is resistant to ToBRFV at 22°C (71.6°F), but the resistance decreases at higher temperatures, such as 30°C (86°F), which is characteristic of several resistance genes, including N-mediated TMV resistance.     

“As we look at the possible virus-resistant tomato cultivars, it is important to understand the role that temperature plays in production,” said Ling. “Temperature is a significant environmental cue that greatly influences host-pathogen interactions. Further study is needed to identify the role of temperature in the genetice resitance to tomatoNN.” 

The study’s findings bring researchers one step closer to controlling ToBRFV. 

“The results described in this paper highlight the significant potential of using the tomatoNN line to breed tomato cultivars resistant to ToBRFV and offers a new approach to managing this important disease for a beloved food staple,” said Ling. 

The research was done in collaboration with the University of California, Berkeley; University of California, Davis; and Iowa State University. 

The Agricultural Research Service is the U.S. Department of Agriculture's chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in agricultural research results in $20 of economic impact.

###

---

Journal

Plant Biotechnology

DOI

10.1111/pbi.70237 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

The N gene protects tomato plants from tomato brown rugose fruit virus infection

ASBESTOS

Two studies published in the Journal of Thoracic Oncology reveal new variant of mesothelioma

International Association for the Study of Lung Cancer

Facebook

XLinkedInWeChatBlueskyMessageWhatsApp

Two Studies Published in the Journal of Thoracic Oncology Reveal New Variant of Mesothelioma

(September 2, 2025—Denver, Colo) Researchers working independently at the University of Hawaii Cancer Center and the National Cancer Institute have discovered, and validated, a new variant of mesothelioma that may lead to more successful treatments. The studies have been published in the Journal of Thoracic Oncology, the official journal of the International Association for the Study of Lung Cancer.

Mesothelioma is a rare and aggressive type of cancer that develops in the mesothelium, the thin layer of tissue that lines the lungs, heart, and abdomen. Asbestos exposure is the primary risk factor.  Median survival time after diagnosis is typically 6 to 18 months.

In these new manuscripts, Dr Michele Carbone of the University of Hawaii Cancer Center, and Dr. David Schrump of the National Cancer Institute, report that mesotheliomas caused by inherited germline BAP1 mutations are a different and much less aggressive  compared to sporadic mesotheliomas and they discovered how to identify and diagnose these patients and how to best treat them.

They found that in addition to mesothelioma, these patients develop multiple tumors and therefore it is critical that they are enrolled in screening programs for early cancer detection. They propose to re-name these tumors as “low-grade-BAP1-associated-mesotheliomas”, L-BAM- to distinguish them from the very aggressive sporadic asbestos-induced mesotheliomas which are resistant to therapy.

The research team of Dr. Michele Carbone at the University of Hawaii Cancer Center discovered this variant of mesothelioma responds to therapy and these patient’s lives can be saved when these tumors are detected early on.  Their new manuscript titled Clinical and Pathologic Phenotyping of mesotheliomas developing in carriers of Germline BAP1 Mutations Michele Carbone et al is in press in the JTO) https://www.sciencedirect.com/journal/journal-of-thoracic-oncology/articles-in-press.

During 1999-2024, the researchers studied 47 families carrying BAP1+/- transmitted in a Mendelian fashion. We characterized these mutations, collected family history, clinical records, prepared family pedigrees and diagnosed their mesotheliomas.

Dr. Carbone’s research team identified 34 different germline inactivating mutations. Among 238 BAP1+/- carriers aged 27-81, 84 were diagnosed with mesothelioma (35%), 1/84 had evidence of asbestos exposure. No mesothelioma was recorded among 123 siblings/relatives who did not inherit BAP1+/- p<0.0001. The 84 BAP1+/- patients developed mesothelioma at a relatively young age; 45.2% developed multiple cancers. BAP1+/- patients had a florid, diffuse mesothelial hyperplasia often present in both pleural cavities, peritoneum and pericardium. Thoracoscopy and laparoscopy showed several multi-cavity ∼1-3 mm whitish flat lesions, imaging was usually negative for cancer. Histology revealed epithelioid cells lacking BAP1 nuclear staining arranged in tubulo-papillary and trabecular architectures, focally invading sub-mesothelial adipose tissue. These findings may lead to the diagnosis of stage IV metastatic mesothelioma. However, Carbone et al found that these tumors may remain indolent for years and, at this early stage, patients do not require aggressive therapy.

“We refer to these tumors as “Low-grade-germline-mutant-BAP1-associated-mesotheliomas, L-BAM” to distinguish them from aggressive, therapy-resistant, sporadic mesotheliomas. For the 1/3 of patients who develop lesions visible by imaging, surgery and/or chemotherapy leads to survival of several years,may be cured. Deep invasion by mesothelioma cells with a solid architecture is rare: these cases have poor survival,” Dr. Carbone said.

In an independent study conducted by the research team of Dr. David Schrump at the National Cancer Institute, National Institutes of Health, Bethesda, Md.,  50 subjects with 32 germline BAP1 mutations underwent state-of-the-art computed tomographic imaging followed by video assisted thoracoscopies and diagnostic laparoscopies. Dr. Schrump and his team identified clinically occult mesotheliomas in 39 of 45 (87%) subjects affecting 63 of 81 (78%) hemi-thoraces and 27 of 32 (84%) peritoneal cavities. These mesotheliomas exhibited histological features distinct from sporadic mesotheliomas and slow clinical progression without therapeutic interventions (median follow-up: 21.8 months; range: 1.7 – 41.1 months). Laboratory experiments identified common as well as mutation-specific, cancer-associated epigenomic alterations in normal fibroblasts and peripheral blood mononuclear cells (PBMC) which correlated with cancer predilection in subjects with BAP1 Cancer Syndrome.

Overall, this prospective study demonstrated that subjects with germline BAP1 mutations have a strikingly high prevalence of subclinical mesotheliomas with unique histologic features and clinical characteristics. Furthermore, mesothelioma risk in subjects with BAP1 Cancer Syndrome may be a reflection of potentially quantifiable epigenetic changes in normal cells. These findings have already led to two ongoing protocols at the NCI (NCT05960773 and NCT06654050) to determine if oral epigenetic agents can abort progression of mesotheliomas to life threatening disease states in subjects with BAP1 Cancer Syndrome. The NCI experience is  detailed in a comprehensive manuscript entitled Prospective Analysis of Mesotheliomas in Subjects with BAP1 Cancer Syndrome: Clinical Characteristics and Epigenetic Correlates of Disease which is also in press in JTO.

https://www.jto.org/article/S1556-0864(25)00984-0/fulltext

“This is a major step in the fight against mesothelioma, one of the most aggressive human cancers. It is also great relief to these families, who are now aware that their tumors can be treated and therefore most of them can live a normal life span,” said Dr. Carbone.

Dr. Carbone’s research progressed over years. Initially, studying a mesothelioma epidemic in 3 small villages in Cappadocia, Dr. Carbone proposed that familial mesothelioma was caused by genetics (Roushdy-Hammady et al. The Lancet 2001); next his team discovered the first gene responsible for familial mesothelioma (Testa et al Nature Genetics 2011); then they identified the mechanisms responsible for the potent tumor suppressor activity of BAP1 (Bononi et al Nature 2017; PNAS 2023) and discovered additional genes that when mutated in the germline may cause mesothelioma (Bononi et al PNAS 2020; Novelli et al., PNAS 2024).

The latest discovery is therefore the result of over 25 years of working with families affected by multiple cases of mesothelioma, he stated.

About the IASLC

The International Association for the Study of Lung Cancer (IASLC) is the only global organization dedicated solely to the study of lung cancer and other thoracic malignancies. Founded in 1974, the association's membership includes more than 11,000 lung cancer specialists across all disciplines in over 100 countries, forming a global network working together to conquer lung and thoracic cancers worldwide. The association publishes the Journal of Thoracic Oncology, the primary educational and informational publication for topics relevant to the prevention, detection, diagnosis and treatment of all thoracic malignancies. Visit www.iaslc.org for more information.

 

About the JTO

Journal of Thoracic Oncology (JTO), the official journal of the International Association for the Study of Lung Cancer, is the primary educational and informational publication for topics relevant to the prevention, detection, diagnosis, and treatment of all thoracic malignancies. JTO emphasizes a multidisciplinary approach and includes original research reviews and opinion pieces. The audience includes epidemiologists, medical oncologists, radiation oncologists, thoracic surgeons, pulmonologists, radiologists, pathologists, nuclear medicine physicians, and research scientists with a special interest in thoracic oncology.

 

---

Journal

Journal of Thoracic Oncology

 

Cities face double trouble: Extreme heat and air pollution cause increasing compound weather events

University of Oklahoma

Facebook

X
BlueskyMessageWhatsAppEmail

NORMAN, OKLA. – U.S. cities are facing a growing threat that goes beyond hot weather or hazy air. New research from the University of Oklahoma reveals that “compound events” — periods when heat wave conditions coincide with high air pollution levels — are becoming more frequent and intense in urban areas across the United States.

According to the National Weather Service, extreme heat is the deadliest weather phenomenon facing the country, causing more deaths each year than any other weather hazard. Chenghao Wang, Ph.D., a professor in the School of Meteorology and the Department of Geography and Environmental Sustainability at OU, received a NASA Early Career Investigator award last year to study the combination of extreme heat and air pollution in urban environments. Findings for Wang and his Sustainable Urban Futures (SURF) Lab, published in sister studies focusing on separate pollution sources, reveal a country dealing with increasing heat stress and pollution, posing a significant threat to public health and urban sustainability.

“Compound heat and air pollution episodes occur when extreme heat and high levels of pollution happen at the same time. They are an increasing threat to public health, especially for urban populations,” said Wang.

Overall, Wang and his team have found that U.S. cities are facing more frequent and intense overlaps of extreme heat with harmful air pollutants than surrounding rural areas. Results published in Urban Climate focused specifically on compound heat and ozone pollution. The study showed that while urban heat waves were more frequent, intense and longer-lasting than their rural counterparts, ozone levels were higher in rural environments. When heat and ozone events did occur together, 88.8% of cities saw higher cumulative heat and ozone intensities than rural areas.

In the other study, published in Environmental Research, Wang and his team examined 23 years of heat and fine particulate matter pollution data, a span that gives them a broad look at trends that shorter-term studies could miss.

“Fine particulate matter, or PM2.5, is small enough in size that it can penetrate deep into the respiratory system and enter the bloodstream, and exposure is associated with adverse health outcomes such as respiratory infections and cardiovascular diseases,” said Jessica Leffel, an MS student in the School of Meteorology and SURF Lab, and the lead author of this work.

When heat waves and PM2.5 episodes occurred together, nearly 98% of cities experienced more frequent and intense compound events, and more than half faced longer durations.

The spatial patterns closely matched those of PM2.5 episodes, suggesting that air pollution plays a dominant role in driving these overlaps. PM2.5 pollution and compound event days have increased in recent years in the western U.S., driven in part by wildfire smoke.

“Wildfire-related PM2.5 is often excluded from air quality assessments under the EPA’s Exceptional Events Rule, which can hide the true health burden of these episodes,” said Leffel. “Integrating wildfire-related PM2.5 into air quality evaluations could better align policy with public health risks.”

A key driver of these dangerous compound events is the urban heat island effect, a phenomenon where cities are warmer than the surrounding rural areas due to factors such as impervious surfaces, fewer trees and dense building structures that trap heat. While rural regions cool down at night, cities stay hot long after sunset as pavement and buildings continue radiating stored heat.

Equally important, elevated pollution emissions from transportation, industry and energy use in cities exacerbate air quality challenges, creating conditions where heat and pollutants interact to intensify health risks.

Because of such differences in environment, fighting this problem will require specific, regionalized strategies that take into account the local factors surrounding compound events. City-specific changes could include urban trees, green roofs or reflective materials. Still, in rural areas where high amounts of pavement are not a contributing factor in compound events, different types of mitigation strategies and policy protections are necessary.

Earlier work that contributed to this PM2.5 paper was conducted with support from the National Weather Center's Research Experiences for Undergraduates (REU) program, which pairs undergraduate students with research mentors to tackle pressing questions in meteorology, climate, and environmental sustainability. The NSF-funded program helps train the next generation of scientists to address complex challenges like urban heat and air quality.

---

Journal

Environmental Research

DOI

10.1016/j.envres.2025.122508 

Article Title

https://www.sciencedirect.com/science/article/abs/pii/S0013935125017608?via%3Dihub

 

Dental fear is widespread—But most people want treatment

New research explores the prevalence of dental fear and memories underlying it, underscoring the need for accessible treatment

New York University

Facebook

XLinkedInWeChatBlueskyMessageWhatsAppEmail

Nearly three out of four adults fear going to the dentist, according to a new study published in the Journal of the American Dental Association.

While dental fear is common, the study—led by researchers at NYU College of Dentistry—also found that most individuals are interested in treatment to overcome it.

People who are anxious about going to the dentist often avoid routine cleanings and care, only visiting a dentist when issues arise. This creates a cycle of fear, as the lack of preventive care can compromise oral health, leading to more fear-inducing pain, infections, and dental work.

“A better understanding of dental fear—and how to increase access to effective treatments for it—holds promise for improving oral and overall health,” said Richard Heyman, a professor in the NYU Dentistry Center for Oral Health Policy and Management and co-director of the NYU Dentistry Family Translational Research Group.

High rates of dental fear

Earlier research shows that more than a quarter of the US population is anxious about going to the dentist, but many of these studies were conducted decades ago. To assess the current state of dental fear, researchers at NYU College of Dentistry surveyed a group of 1,003 adults that was representative of the US population based on age, gender, race, education level, region, and household income.

They found that dental fear is even more widespread than previously thought: 72.6 percent reported some amount of dental fear, with 45.8 percent saying they have moderate fear and 26.8 percent reporting severe fear. 

When those with moderate or severe fear were asked whether they would be interested in a free, brief treatment for dental fear that could be completed at home, the majority (71.2 percent) expressed interest. (Those who were not interested indicated skepticism about whether the treatment would be effective, reported satisfaction with their current coping strategies, or had concerns about time.)

“While dental fear is highly treatable, few professionals have received relevant training or offer treatment. Brief, virtual dental fear treatments using apps and telehealth have the potential to reach many people, regardless of where they live,” said Heyman. 

Heyman and his colleagues have developed a program called Dental FearLess that uses an app and, if needed, a one-on-one telehealth session, to treat dental fear using principles of cognitive behavioral therapy and mindfulness. In a pilot study, half of participants were no longer fearful after completing the program, which continues to be studied in an ongoing clinical trial.

“While the widespread prevalence of dental fear suggests it may actually be growing in the general population, we are making progress in expanding the access to treatment,” added Heyman.

The role of memory in dental fear

Given how common dental fear is, NYU Dentistry researchers are also working to better understand how it emerges. Prior research shows that more than half of those who have high levels of dental fear have had negative experiences at the dentist, often as a child or adolescent, but little attention has been paid to the role of memory in developing and maintaining these fears. 

“Memories of traumatic dental care can be remarkably vivid and tend to have lifelong implications,” said Kelly Daly, an assistant research scientist in NYU Dentistry’s Family Translational Research Group.

To explore the connection between memory and dental fear, Daly and her colleagues analyzed survey data and written reflections from parents about their own dental fear as well as their children’s fear; the findings are published in the journal Oral.

They found that many people with dental fear have memories of pain and negative interactions with dentists—including some behaviors that have since fallen out of favor, such as a dentist putting a hand over a child’s mouth to stop disruptive behavior, a technique that has been removed from clinical guidelines. Patients also recounted experiences that led them to perceive dentists as untrustworthy, whether they felt humiliation, that they were not being listened to or believed, or that dentists were recommending unnecessary treatments. 

“The salience of these memories—particularly ones from childhood—and ways that lifelong oral healthcare can be compromised are important lessons for practicing dental providers,” said Daly. “Many of these negative experiences can be avoided with open and transparent communication between providers and patients.”

In addition to Heyman, authors of the JADA study include Daly, Salomi Aladia, Sarah Harris, Nicole Roitman, Annette Kim, and Amy Smith Slep of NYU Dentistry. In addition to Heyman and Daly, authors of the Oral study include Jennie Ochshorn, Ronni Lipnitsky, Adrianna Rozbicka, and Sidhant Athilat of NYU Dentistry, as well as Suher Baker of the Brooker Memorial Institute Pediatric Dental Center and Allan Pike, a leader in pediatric dentistry. Data analyses for and writing of the two papers were supported by the National Institute of Dental and Craniofacial Research (UH3DE029453), part of the National Institutes of Health (NIH). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.

---

Journal

The Journal of the American Dental Association

DOI

10.1016/j.adaj.2025.07.004 

Subject of Research

People

Article Title

A census-matched survey of dental fear and fear-treatment interest in the United States

Article Publication Date

2-Sep-2025