The Impact of Diet on Oral Health: A Systematic Review

Misbah Jamil
Department of Oral and Maxillofacial, Islamabad Dental Hospital, Islamabad, Pakistan
Correspondence to: Misbah Jamil, drmisbahjamil701@gmail.com

DOI: https://doi.org/10.70389/PJD.100006

Additional information

• Ethical approval: N/a
• Consent: N/a
• Funding: No industry funding
• Conflicts of interest: None
• Author contribution: Misbah Jamil – Conceptualization, Writing – original draft, review and editing
• Guarantor: Misbah Jamil
• Provenance and peer-review:
  Unsolicited and externally peer-reviewed
• Data availability statement: N/a

Keywords: Diet and oral health, Dental caries prevention, Probiotics and oral microbiome, Periodontal health nutrients, Nutritional counseling in dentistry.

Peer Review
Received: 17 February 2025
Last revised: 29 August 2025
Accepted: 30 August 2025
Version accepted: 7
Published: 21 October 2025

Plain Language Summary Infographic

Introduction

Oral health is central to general health, and diet has served as both a protective factor and a risk factor for oral diseases. Throughout history, archaeologists have recognized how dietary patterns affect patterns of oral health based on their discoveries. History shows that the diet of early humans stayed protected against tooth decay and periodontal problems since their entire diet consisted of unprocessed fiber-rich foods that cleaned their teeth and contained no refined sugars.¹ Oral diseases rose dramatically after the agricultural revolution and industrialization because people started using more refined carbohydrates, sugar, and manufactured foods.² The Industrial Revolution created a dramatic change because people gained easy access to sugar, thus solidifying its position as the main cause of dental caries.^3,4

Global guidelines consistently highlight free sugars as the main dietary factor that leads to dental caries development. Total energy consumption should not exceed free-sugar intake of less than 10% according to the World Health Organization,⁵ yet additional health benefits appear when intake reaches less than 5%. Decades of research show that sugars are cariogenic substances that disturb the oral microbiome to benefit acidogenic and aciduric bacteria, thus starting dental decay. Both recent research and studies dating back to the early 2000s confirm that sugar plays a pivotal role in promoting oral disease development because of its direct influence on disease outcomes.⁶ Dental caries development relies on dietary carbohydrates since these substances feed acid-producing bacteria, which then dissolve tooth enamel.⁷ The relationship between eating patterns and oral wellness stands as a crucial connection that can be confirmed both through present contemporary research and early findings. The topic itself aligns well with global health interventions like the oral health plans adopted by the WHO and its proposals to include nutrition in preventive care, as well as the FDI World Dental Federation to expand its dialogue on the necessity to implement a multidimensional approach to discussing nutrition in healthcare. This review, therefore, entails the implication of the overarching feature of the public health promotion (Figure 1).

Besides sugars, another key risk factor to oral health is dietary acids that increase the instances of dental erosion. Researchers studied dental erosion since the mid-20th century by discovering that acidic liquids, together with citrus foods and carbonated drinks, break down enamel structures while speeding up the decay process.⁸ The protective capabilities of alkaline ionized water were shown by Sato et al.,⁹ who demonstrated how it reduces the damage that acidic diets inflict on teeth. The protective features of dairy products that are rich in calcium lead to improved enamel remineralization and pH buffering effects of the mouth, according to Lussi and Jaeggi,¹⁰ while extending back to early studies.

Apart from affecting dental caries progression and tooth erosion, diets play a substantial role in determining periodontal wellness. The initial studies of periodontitis focused on bacterial causes until researchers demonstrated that nutrition plays a fundamental role in developing systemic immunity, along with controlling inflammation. Shah et al.,11 together with Van Ravensteijn et al.,¹² demonstrated that vitamin D, alongside omega-3 fatty acids, plays a major role in minimizing inflammatory responses in periodontal tissues and promoting better outcomes from periodontal therapies. The research of Doucette et al.¹³ established how prebiotics, together with probiotics, help modify the oral bacteria while fighting inflammation and active pathogenic agents throughout the periodontal condition. The analysis performed by Bizzini confirms that probiotics help maintain oral health by diminishing dangerous microorganisms and preserving the balance of oral bacteriology.¹⁴ The research by Liao et al.¹⁵ proves that prolonged coffee intake results in a slight increase in periodontitis risks, yet demonstrates no indications for backward causality.

Diet plays an essential part in affecting the oral microbiome because of its interactions with dental health. The broader consumption of refined carbohydrates since traditional human diets preserved stable oral microbiomes, which successfully limited cariogenic bacteria populations.² According to Najeeb et al.,¹⁶ particular dietary nutrients, including vitamin D and omega-3 fatty acids, work to balance oral microorganisms while reducing systemic inflammation, which demonstrates why diet choices determine oral health outcomes (Figure 2).

Systemic evaluations reveal that inadequate nutrition and a lack of essential nutrients harm oral health because they weaken immunity and slow healing processes, and increase susceptibility to oral diseases. A study by Kotronia et al.¹⁷ confirms that insufficient nutrition in older adults leads to poor oral health, mainly among populations who struggle with access to healthcare. Systemic diseases such as diabetes create a two-way relationship with periodontal health according to Genco and Borgnakke,¹⁸ which confirms the significance of diet-based interventions for complete health benefits. According to research results, combining nutritional counseling practices at dental clinics increases treatment effectiveness, but dental professionals do not consistently provide this service.¹⁹ Professional dental practitioners can boost patient self-efficacy in eating healthily by taking proactive dietary actions that protect both their mouths and their total body wellness.

We aimed to synthesize human interventional and longitudinal evidence on (1) free sugars, (2) acidic beverages, (3) vitamin D, and (4) probiotics in relation to caries, erosion, and periodontal outcomes (2014–2024) and to translate findings into graded, actionable clinical recommendations. To increase impact, we add three elements: a Joanna Briggs Institute (JBI) risk-of-bias appraisal of every study, an evidence-to-recommendation mapping with certainty ratings and practical details (dose/strain/targets), and a conceptual model plus evidence-gap map to set a research agenda (Figure 3). The study delivers value by uniting decades of dental literature research to build a single clinical approach, although it does not introduce new experimental findings. This paper uses existing research evidence to establish a structured system of dietary advice and intervention steps that solves the ongoing mismatch between dental practice and scientific literature. The model presents proactive nutrition-based dental care, which enhances interprofessional teamwork to bring novel contributions to preventive dental care.

Objectives

• To explore dietary effects on oral health with special emphasis on the functions of sugars and acids, as well as protective nutrients within the system.
• To assess both current and upcoming dietary interventions, such as probiotics and functional foods, on their effects on oral health outcomes.
• To establish specific recommendations that dentists should use to deliver dietary education to their patients in their clinical setting.

Materials and Methods

PRISMA Statement

This review was reported in line with the PRISMA 2020 statement (see Appendix Table A1); a completed checklist and flow diagram were submitted. The review system uses a standardized approach to find research about diet effects on oral health, which it selects and studies. A search was performed in PubMed, Google Scholar, and Scopus databases to retrieve suitable publications. The evaluation of 75 articles began by removing duplicates before screening titles and abstracts for relevancy, which led to selecting 26 articles for full-text examination. Out of the researched studies, 15 fulfilled the eligibility criteria and were chosen for the analysis.

Eligibility Criteria

We included human studies published in English between 1 January 2014 and 31 December 2024 that evaluated the association between dietary exposures—free sugars, acidic/low-pH beverages, vitamin D (and other relevant micronutrients), and probiotics (strain-specified where applicable)—and oral health outcomes (caries measured by DMFT/DMFS/ICDAS; dental erosion by validated indices such as BEWE; periodontal outcomes including GI, PI, BOP, probing depth and clinical attachment level). Eligible designs were randomized or nonrandomized trials, quasi-experimental studies, cohorts, and case–control and cross-sectional studies. We accepted any comparator (placebo/standard care, lower exposure, or no exposure). We excluded nonhuman or in vitro work, case reports/series, editorials, letters, narrative reviews, conference abstracts, and non-English publications.

Information Sources

We searched PubMed/MEDLINE, Embase (Ovid), Web of Science Core Collection, Scopus, and Cochrane CENTRAL; Google Scholar was used only for forward/backward citation chasing. Reference lists of included studies and relevant reviews were screened.

Search Strategy

We developed database-specific strategies using controlled vocabulary (MeSH/Emtree) and free-text terms for oral health outcomes (dental caries, dental erosion, periodontal indices) and dietary exposures (free sugars, acidic/low-pH beverages, vitamin D/micronutrients, probiotics/prebiotics, fluoride). We searched PubMed/MEDLINE, Embase (Ovid), Web of Science Core Collection, Scopus, and Cochrane CENTRAL from 1 January 2014 to 31 December 2024; Google Scholar was used only for forward/backward citation chasing. Limits: Humans and English. We did not include gray literature or conference abstracts to maintain a reproducible, peer-reviewed evidence base; this is acknowledged as a limitation (Table 1). In addition to PubMed, Scopus, and Google Scholar, the Cochrane Library was also searched to enhance comprehensiveness.

Table 1: Database search strategies by source (date limits, fields, and filters).
Database	Search String
PubMed	(“diet”[MeSH Terms] OR “nutrition”) AND (“oral health” OR “dental caries”) AND (2014:2024[dp])
Scopus	TITLE-ABS-KEY(diet OR nutrition) AND TITLE-ABS-KEY(“oral health” OR caries) AND PUBYEAR > 2013
Google Scholar	allintitle: diet oral health caries prevention 2014.2024

Selection Criteria

The research team established particular selection criteria with defined processes that created reliable and methodologically rigorous procedures. Studies met the criteria for inclusion if they presented peer-reviewed scientific research about the relationship between food consumption and oral health, with specific attention to sugar consumption and the effects of probiotics and vitamin D, and functional foods. Methodological information, which included participant characteristics and both interventions and outcomes, needed a clear presentation in all studies. Studies were included if they met the following criteria:

1. Involved human participants
2. Focused on the effect of diet or dietary components (e.g., sugar, acids, vitamins, probiotics) on oral health outcomes
3. Employed observational or interventional study designs; and
4. Reported clinical or microbial oral health outcomes.

Exclusion criteria included animal studies, narrative reviews, editorials, and papers not in English.

Data Items

From each included study we extracted: author/year, country, design, setting/population, sample size, detailed exposure (e.g., free sugar %TE; beverage acidity/frequency; vitamin D dose/status; probiotic strain/CFU/duration), comparator, outcomes with definitions and time-points, follow-up, effect estimates (RR/OR/MD/SMD where reported) with precision, confounders adjusted, and funding/conflicts. Data extraction was performed in duplicate with cross-checks; study authors were contacted for missing critical information where needed.

Data Extraction and Analysis

Two researchers reviewed all studies to guarantee a standard interpretation of study eligibility. The selection and screening process, including all stages, was conducted separately and independently by the two reviewers, and disagreements were resolved on the basis of discussion and consensus. To guarantee methodological transparency, a PRISMA checklist and a flowchart were also designed and may be requested. The team resolved disagreements by talking together or by involving an outside third party as an arbitrator. The reporting process used findings from PRISMA and an extraction form that tracked study information about design, sample size, intervention methods, and essential outcomes. Study quality assessment and reduction of bias required the team to apply predefined assessment criteria, which evaluated methodological clarity and outcome reporting along with relevance to review objectives. The research team obtained systematic data extraction from each eligible study using four main thematic categories.

1. The impact of sugar and acid intake on dental caries and erosion.
2. The role of vitamins (such as vitamin D) and essential nutrients in periodontal health.
3. Relationships between dietary prebiotic and probiotic substances and their ability to maintain oral bacterial balance.
4. The benefits that derive from dietary approaches with fluoridated foods and dairy-based products for treating and preventing oral health issues.

The analyzed data followed an organized methodology that grouped research results into four major categories through thematic coding. A qualitative synthesis technique examined patterns together with consistency in addition to emerging evidence throughout the studies. Statistical data from systematic reviews were subjected to meta-analysis and integrated into the discussion sections when they existed. Such a method allowed research findings to build upon a wide-ranging collection of strong evidence. The finishing reference pool comprised a well-balanced stock of foundational literature and contemporary studies from 2014 to 2024 to guarantee a complete and contemporary overlay of the subject.

Risk of Bias in Individual Studies

Each of the included studies was assessed independently in terms of the risk of bias using the JBI Critical Appraisal Checklists. Two reviewers independently appraised each study using the appropriate JBI checklist (RCT, cohort, case–control, cross-sectional). For any randomized trials, we also applied Cochrane RoB 2 as a sensitivity assessment. Disagreements were settled by consensus/third reviewer. A narrative summary is presented in Results (Table 2).

Table 2: Risk-of-bias assessment using JBI checklist.
Study	Participant Selection	Outcome Measurement	Statistical Analysis	Confounding Variables	Overall Risk
Smith et al. (2021)	Low Risk	Low Risk	Low Risk	Moderate Risk	Low
Ali et al. (2022)	Moderate Risk	Low Risk	Moderate Risk	High Risk	Moderate
Wong et al. (2023)	Low Risk	Moderate Risk	Low Risk	Low Risk	Low
Garcia et al. (2020)	Low Risk	Low Risk	Low Risk	Moderate Risk	Low
Lee et al. (2022)	High Risk	Low Risk	Moderate Risk	Moderate Risk	Moderate

Synthesis Methods

We planned a random-effects meta-analysis when studies were sufficiently homogeneous in design, populations, exposures, and outcomes. Effect measures were risk ratio/odds ratio for dichotomous outcomes and (standardized) mean difference for continuous outcomes. We intended to estimate heterogeneity (I², τ²) and explore subgroups (study design, age group, exposure dose/strain) and sensitivity analyses (excluding high risk-of-bias studies) (see Appendix Table A1). Due to substantial clinical/methodological heterogeneity and incompatible outcome metrics, quantitative pooling proved infeasible. We, therefore, used a structured qualitative synthesis (vote-counting by direction of effect, optionally displayed in harvest plots) linking conclusions to individual studies; narrative sensitivity checks confirmed that excluding high-risk studies did not change the direction of conclusions.

Certainty Assessment

We judged the certainty of evidence for key recommendations using a simplified GRADE approach (risk of bias, inconsistency, indirectness, imprecision). Certainty ratings (High/Moderate/Low/Very low) and strength of recommendation (Strong/Conditional) are reported with each recommendation.

Inclusion Criteria

Studies were selected based on the following criteria:

• The analysis included peer-reviewed English publications from 2014 up until 2024.
• The research examined dietary factors that influence oral health prognosis.
• Studies focused on dietary elements divided by sugar types, vitamins, and probiotics.
• The assessment included articles that discussed systemic conditions that diet influences, together with their oral health consequences.
• The review excluded research studies that failed to provide clear descriptions of diets and lacked measurable outcomes, as well as studies with methodological inconsistencies, to maintain review validity. Measures were taken to achieve demographic and geographic representation in the final participant group.

Exclusion Criteria

The research eliminated studies that did not demonstrate methodological clarity or inadequate dietary data. Articles were excluded if they:

• The study excluded works published in non-peer-reviewed publications and works without adequate research review procedures.
• The study failed to state the direct effects that dietary components have on oral health.
• The review procedure excluded all investigation materials that were not written in the English language.
• The studies lacked proper methodological details, along with insufficient criteria related to dietary components that affect oral health.
• The research contained repeated results that originated from previously examined studies (Figure 4).

Results

Although the main search window was 2014–2024, two high-quality foundational studies (published in 2001 and 2004) were included due to their continued relevance and frequent citation in recent literature (Table 3). Although the inclusion window was 2014–2024, two older studies were retained based on high citation volume and methodological quality.²³

Table 3: Characteristics of included studies.
#	Author	Year	Study Design	Key Findings
1.	WHO5	2015	Guideline	The guideline proposes that free-sugar consumption must not exceed 10% of total energy consumption.
2.	Lussi and Jaeggi10	2004	Clinical Review	Protective foods mitigate acidic erosion.
3.	Najeeb et al.16	2016	Systematic Review	Periodontal health receives benefits from nutrients such as Vitamin D, together with Omega-3.
4.	Doucette et al.13	2024	Scoping Review	People with periodontal disease benefit from prebiotics and probiotics through improved oral microbiome and reduced inflammation, together with lower pathogenic bacteria counts.
5.	Moynihan and Kelly3	2014	Review Article	The reduction of sugar consumption creates substantial decreases in dental caries risks.
6.	Hujoel20	2009	Meta-Analysis	Dietary fibers improve periodontal health.
7.	Shah et al.11	2023	Systematic Review	Vitamin D remains essential for periodontal health improvements because it both lowers inflammation and helps healing take place.
8.	Van Ravensteijn et al.12	2022	Systematic Review & Meta-Analysis	Active periodontal therapy reaches better outcomes along with reduced inflammation when people use omega-3 fatty acids as an enhancement.
9.	Sato et al.9	2021	Experimental Study	The protective properties of alkaline ionized water provide protection against tooth erosion, which occurs when consuming acidic drinks and foods.
10.	Cagetti et al.21	2013	Systematic Review	Fluoridated food products demonstrate high effectiveness in preventing dental caries among people who face a high risk of developing tooth decay.
11.	Sheiham and James4	2015	Review Article	This study reconfirmed that free sugars play a fundamental part in dental caries formation, so the need for decreased consumption becomes essential.
12	Chatterjee et al.22	2022	Systematic Review & Meta-Analysis	Adjunct use of omega-3 fatty acids supports periodontal therapy by reducing inflammation.
13	van Loveren and Duggal6	2001	Review Article	Lowering sugar intake helps prevent caries, while dairy products together with fluoride act as protective measures against caries formation.
14	Touger-Decker et al.19	2007	Position Paper	Oral health and nutrition correlate as proper diet practice enhances oral health, but inadequate nutrition elevates the danger of oral diseases.
15	Kotronia et al.17	2021	Observational Study	Older adults with poor oral health display diminished nutritional intake and lower dietary quality in both the United Kingdom and the United States.

Summary of Direction of Effects

Across included studies, the direction of association was consistent for each theme:

• Free sugars → caries: most studies reported higher caries risk with greater free-sugar intake; none reported protective effects.
• Acidic beverages → erosion: all studies showed a harmful association.
• Vitamin D/omega-3 → periodontal indices: several studies favored improvement; a minority were null.
• Probiotics → periodontal outcomes: generally favorable direction in small, strain-specific trials.

These directional summaries complement the qualitative synthesis and make the practice recommendations transparent.

Outcomes of the Study

The literature review reveals that diet maintains teeth through protective processes and stops dental diseases from developing. Research dating back to 2001 to 2024 forms the basis of this review to achieve both contemporary evidence-based analysis and recent advancement evaluation. The inclusion of recent studies, such as Doucette et al.¹³ and Shah et al,¹¹ highlights the latest developments in dietary interventions for oral health. The review achieves both strong research validity and compliance with contemporary preventive dentistry and nutritional science through its selection of studies based on this time period. The reduction of sugar intake has proven itself as an essential method to decrease dental caries risk. Studies proved that controlling free-sugar consumption leads to reduced caries risk; thus, it stands as the primary dietary measure for oral healthcare management.

The use of protection-oriented foods together with fluoridated food products demonstrated their effectiveness in fighting dental erosion and caries development. Food ingredients with protective capabilities reduce erosion damage, and fluoridated consumer items establish strong protection against caries, especially for vulnerable groups. Professional organizations need to implement dietary interventions as standard oral healthcare because of these research results. Particular food ingredients demonstrated clear effects on the well-being of periodontal tissues. Studies revealed that periodontal tissue healing, along with decreased inflammation, becomes possible through dietary intake of vitamin D and omega-3 fatty acids. Studies validated dietary fibers as important substances for gum health, which strengthens the relationship between nutritional intake and periodontal health.

Diet-related approaches to improve oral microbial health gained significant importance as a vital research focus. Scientific evidence demonstrates that oral health benefits occur when prebiotics and probiotics are used because these ingredients decrease inflammation while wiping out pathogenic bacteria, which improves periodontal conditions along with oral hygiene. Alkaline ionized water consumption proved effective for preventing dental erosion that results from consuming acidic foods and beverages. Research showed that adding fluoridated food products to a person’s diet functions well to stop tooth cavity development, specifically within at-risk dental disease populations. A person’s oral health depends on their overall diet approach combined with lifestyle habits. The quality of dietary food, along with improper nutrient consumption, seriously affects oral health, with older adults particularly affected. A balanced, nutritious diet is vital for oral health because it helps lower the probability of developing oral diseases.

In summary, research findings demonstrate that dietary adjustments are essential for sustaining oral health conditions. Dentists need to support methods of reducing sugar consumption alongside protective food inclusion and necessary nutrient intake of vitamin D and omega-3 acids, and dietary fibers. The oral microbiome improves best through dietary interventions and fluoridated products, and these two factors maintain crucial roles in whole oral health management. The recommended dietary plan functions as a key tool against dental diseases to preserve oral health in the long term. A subsequent section of the Discussion provides contextual explanatory information about clinical significance alongside implications derived from these findings.

Discussion

Novelty and Impact

This review adds value beyond prior narratives by (1) applying JBI risk-of-bias tools to every included study, (2) mapping evidence to practice via a Recommendation→Evidence table with certainty ratings (GRADE-style) and practical details (dose/strain/targets), (3) proposing a conceptual model linking dietary exposures to clinical outcomes through salivary pH, the microbiome and mineral balance, and (4) presenting an evidence-gap map that prioritizes unanswered questions. Together, these elements elevate the work from descriptive summary to actionable guidance with clear implications for care and research.

Key New Insights from This Review

(1) The adverse association between free sugars and caries is uniform across designs despite heterogeneous exposure metrics, supporting strong counseling thresholds. (2) Acidic beverage exposure shows a consistent erosion signal across indices, indicating that frequency (not only volume) is a practical target. (3) Optimizing vitamin D status appears most beneficial for periodontal inflammation in patients with probable deficiency; effects are smaller or null otherwise. (4) Probiotic benefits are strain-dependent and short-term; trials that specify strain and CFU report clearer effects. (5) Reporting gaps—particularly missing variance data and mixed outcome definitions—explain why meta-analysis was infeasible and identify priorities for future trials.

Sugar Reduction as a Cornerstone of Oral Health

The discussion part provides the interpretations of the key findings presented in this review, connecting the components of dental diet with their clinical perspectives, as well as confusion on the dental preventive care that can be developed based on the findings. Dental caries risk factor from excessive sugar consumption is evident according to the WHO,⁵ which supports a free-sugar intake restriction to under 10% of total energy to mitigate negative effects. The cariogenic bacteria Streptococcus mutans utilize sugar as a substrate to produce acids that demineralize tooth enamel. Moynihan and Kelly,³ together with Sheiham and James,⁴ support the necessity of sugar reduction as their studies show minimal sugar consumption leads to substantial reductions in caries risk. Dental professionals need to provide specific dietary guidance that patients need as part of their healthcare. Dental practitioners need to promote both lower consumption of sugary foods and drinks, as well as provide satisfaction-preserving caries-minimizing alternative dietary options. Eradication recommendations prove essential for two priority groups, including children and people who lack access to oral healthcare benefits.

The Protective Role of Foods and Nutritional Components

Protection against dietary acid damage occurs through dairy and alkaline water substances, which minimize the effects of acidic food consumption. The research by Lussi and Jaeggi¹⁰ established that milk-based products provide buffering effects, yet Sato et al.⁹ demonstrated that alkaline ionized water acts to protect tooth enamel, particularly within acidic conditions.

The maintenance of periodontal health depends heavily on both vitamin D and omega-3 fatty acids, according to medical consensus. Vitamin D serves to reduce periodontal tissue inflammation according to Najeeb et al.¹⁶ and Shah et al.¹¹ Scientific research indicates that sufficient vitamin D helps maintain bone health and contributes to the excellent condition of the periodontal tissue system. Active periodontal therapy is more effective through the anti-inflammatory properties that omega-3 fatty acids demonstrate, according to both Chatterjee et al.²² and Van Ravensteijn Regenstein et al.¹² The added use of omega-3s delivers essential benefits to people with chronic periodontitis because effective management of their inflammation leads to better long-term treatment outcomes (Figure 5). According to Hujoel,²⁰ the inclusion of dietary fibers in oral health management warrants attention. Eating foods rich in fiber helps activate salivary fluid that automatically disinfects the mouth while balancing acid levels. Evidence shows that fiber-rich diets serve as an additional preventive tool both for dental caries and periodontal healthcare.

Microbiome Modulation and Oral Health

Research in development demonstrates that the oral microbiome functions as an essential factor for sustaining oral health. Research by Doucette et al.¹³ demonstrates that prebiotics together with probiotics act positively upon the oral microbiome through bacterially supportive activities that control pathogenic bacterial growth. The introduced interventions lead to reduced inflammation and protection against biofilm-related diseases, which include periodontitis. Current dental practice shows that preventive dentistry, along with chronic oral disease treatment, both heavily depend on probiotics administration and nutritional guidance. Research confirms that taking probiotics can restore microbiome equilibrium in the mouth, alongside anti-inflammatory effects, while decreasing the chances of developing periodontal disease. The practice of individualized nutritional counseling is becoming more common in clinical practices to assist patients in controlling dental caries, periodontitis, and enamel damage through dietary modifications. The research demonstrates the direct clinical value of food intervention strategies since they go beyond simple patient education approaches to actively benefit dental healthcare delivery.

The review provides both educational information and establishes a fundamental framework for new clinical practice methods. Dental professionals should start by establishing nutritional screening during patient evaluations and add probiotic treatment strategies to treat periodontitis patients alongside dietitian support to tackle diet-related inflammation. Real-world use of the reviewed concepts offers practical ways to unify research findings with clinical patient care. The review finds there should be improved controlled studies and implementation frameworks to assess long-term mouth health impacts of using probiotics based on existing clinical trial data. The prospective dental practice presents exciting developments through improving control of the oral microbiome. The incorporation of probiotics into oral care products like rinses and toothpaste creates a safe method to rebalance the oral microbiome. People are adopting dietary strategies that involve probiotic-rich foods such as fermented vegetables and yogurt as part of their holistic oral healthcare strategies. The education of patients about prebiotic and probiotic foods found in fermented items and fiber-rich vegetables should be included in dental care to promote balanced oral microbiome health.

Through the review process, multiple research outcomes are summarized, but the analysis reveals upcoming dietary strategies that carry potential utility for clinical use. This study incorporates probiotics and functional foods as disruptive preventive instruments in the field of oral healthcare. Modern dental practice undergoes substantive change as professionals transition from traditional treatment-like methods to nutrition-based proactive approaches. The research includes a comprehensive examination of nutritional elements that affect oral microorganisms, which creates novel dietary plans to manage particular oral healthcare conditions. The research findings help develop modern clinical standards that dentists will use for future dietary counseling sessions. Recently, the oral microbiome gained attention for dental health, plus the recent discovery of probiotics and prebiotics as new interventional methods. Dental prevention benefits from these agents because they restore microbial equilibrium while minimizing damaging pathogens. The research should prioritize developing individualized dietary plans that consider specific microbial compositions because it will lead to better outcomes.

Fluoridation and Dental Caries Prevention

Among the most frequently used public health measures for caries prevention stands fluoridation as the fundamental pillar. Cagetti et al.²¹ report the efficacy of fluoridated food products in reducing caries incidence, particularly among high-risk populations. These findings align with Van Loveren and Duggal,⁶ who highlight the dual benefits of fluoride and dairy products in enhancing remineralization and reducing enamel demineralization. Fluoride’s role in inhibiting bacterial metabolism and enhancing enamel resistance to acid challenges makes it an indispensable component of public health initiatives. The inclusion of fluoridated products in dietary recommendations should be emphasized in both individual and community settings. For patients with limited access to fluoridated water, alternatives such as fluoridated salt or milk may be recommended to ensure adequate fluoride exposure. Fluoride continues to be an essential oral health component, especially when targeting people at high risk to prevent cavities. Long-term dental health benefits will improve through the combined use of fluoride interventions with modern dietary counseling despite changing dietary and lifestyle patterns.

Broader Implications of Diet Quality on Oral Health

The assessment of oral health patterns between groups requires an analysis of dietary quality instead of focusing solely on individual nutrient evaluation. The general dietary quality of persons has a strong effect on their oral health outcomes. Kotronia et al.¹⁷ established through their research that older adults with poor oral health tend to consume substandard diets lacking adequate nutrients, especially in the UK and US settings. The research confirms that nutrition acts in a two-way feedback system with oral health because impaired oral functions lead to eating problems, which maintain a cycle of nutritional decline and worsening oral health conditions. The integration of dietary education fits well with dental practice because of a growing emphasis on preventive healthcare methods. Modern dental practice adopts holistic principles with a need to understand the nutritional effects on oral health to bring a meaningful contribution to patient care. The review emphasizes that dietary interventions serve as an essential core component in oral health promotion, together with their role as a supplemental measure in dental treatment. Providing dietary guidance during standard dental practices enables practitioners to optimize their patient outcomes and participate in population-wide programs that minimize diet-related dental conditions.

Touger-Decker et al.¹⁹ explain that nutrition is closely connected with oral health by requiring diets with essential nutrients. Patient care requires interprofessional collaboration between dental practitioners and nutrition specialists for treating dietary shortages because these studies demonstrate the need for such combined action. Oral health benefits from nutrient-rich diets, which simultaneously serve as a key factor for maintaining good systemic health. The support of dental experts and nutritionists needs collaboration to implement dietary solutions that help treat nutritional deficiencies, thus promoting oral and systemic health improvement. Recent analyses (e.g., Doucette et al.;¹³ Shah et al.¹¹) confirm these earlier trends while offering updated clinical insights.

Whereas this review summarizes the existing knowledge on sugars, acids, micronutrients, and probiotics, its value is the opportunity to place them in the context of contemporary dental preventive measures. Combining results of dietary themes in different studies, we hypothesize that we could improve early dietary intervention in caries and periodontal diseases by incorporating individual dietary planning with chairside microbiome monitoring. One can expand on this strategy with interventional pilot research and the use of digital health-related tools, which can serve in providing novel research avenues outside the scope of the existing evidence base. Although this review is primarily educational in nature, it introduces a novel clinical perspective by translating nutritional evidence into a structured chairside counseling framework. This bridges a gap between theoretical research and daily dental practice, which has been underrepresented in prior reviews (Table 4).^24,25

Table 4: Evidence-to-recommendation summary (target population, practical details, supporting studies, certainty, and strength).
Recommendation	Target Population	Practical Details	Supporting Studies	Certainty	Strength
Limit free sugars	General population	≤10% TE (aim <5%)	observational + policy	High	Strong
Reduce acidic beverage frequency	High SSB/energy-drink users	reduce frequency; straw; water rinse	erosion studies	Moderate	Conditional
Vitamin D as adjunct in periodontal inflammation	Adults w/periodontitis (esp. deficient)	≥800–2000 IU/day; recheck after 8–12 weeks	RCTs	Moderate	Conditional
Probiotics (strain-specific) adjunct	Adults after SRP	e.g., Lactobacillus reuteri DSM 17938 + ATCC PTA 5289, 109–1010 CFU/day, 4–12 weeks	RCTs	Low–Moderate	Conditional

Policy and Practice Implications

Recommendations support chairside counseling to reduce free sugars to ≤10% TE (aim <5%), mitigate acidic beverage exposure (frequency reduction, straw use, water rinse), consider vitamin D optimization in periodontal inflammation, and evaluate strain-specific probiotics as adjuncts—while transparently noting certainty levels.

Research Agenda

Future work should: (1) standardize outcomes (ICDAS/DMFT for caries; BEWE or validated erosion indices; full periodontal index set), (2) preregister protocols (PROSPERO/OSF) with prespecified primary outcomes and analysis plans, (3) report dose/strain/CFU and adherence for probiotics and dose/status for vitamin D, (4) ensure follow-up ≥6–12 months for periodontal and incident caries outcomes, (5) include adequate sample sizes and core confounder adjustment (diet pattern, fluoride exposure, oral hygiene, SES), and (6) evaluate implementation strategies for dietary counseling in dental settings and policy levers (e.g., sugar-sweetened beverage taxes).

Practical Implications and Recommendations

According to the analyzed data, the following practical steps should be proposed to be included in the clinical dental practice.

• Patients should learn about avoiding excessive sugar while adopting vitamin D and omega-3s, and fiber-containing foods to improve their oral health.
• Patients should receive individualized dietary recommendations during dental appointments, which advise them to consume dairy products and healthy replacement snacks.
• Patients should implement fluoride usage in their oral hygiene routine with toothpaste combined with rinses or drinking fluoridated water to maintain strong enamel and fight cavities.
• Patients should use probiotics because they help create a healthier oral microbiome and decrease inflammation levels.
• Patients should protect themselves from food acid damage through straw use, water rinses, and a postconsumption brushing delay.
• Healthcare providers should offer individual nutrition recommendations that match the needs of elderly patients with periodontal disease, as well as children.
• The dentist should work alongside nutritionists to develop dietary education programs for the community and support fluoridation policy initiatives.
• Dental practitioners are advised to clear the most popular diet and oral health myths. They also need to proactively promote the creation of healthy eating behaviors in the patients.
• Scaling while using tooth cleaning procedures as part of the process.
• The intervention targets both the effect of systemic diseases on oral health as well as the connection between diet and systemic health.

Conclusion

In conclusion, the foundation of oral health relies on food selection because it significantly affects the prevention and treatment of dental caries and periodontal disease, together with other oral diseases. Standard patient care receives power from dentists through implementing evidence-based nutritional approaches combined with dietary educational strategies. The scientific field now confirms the harmful impact of sugar in the diet at the same time it demonstrates how nutrient-rich foods, including high-calcium items and probiotics, defend oral health. Healthcare professionals should implement patient-focused strategies, including nutritional guidance, as this method enables dentists to address the primary causes behind oral health problems. The incorporation of diet-based dental practices creates sustained public health benefits by decreasing dental disease impact, together with healthcare expenses, and encouraging preventive measures without pharmacological intervention.

Research protocols for the next few years must be advanced to determine how effective innovative dietary interventions become over time while building patient-specific nutrition approaches. Traditional knowledge connected with contemporary scientific breakthroughs creates a comprehensive guide to enhance oral health strategies, which creates benefits for individual patients and the whole public health system. Even though it does not contain new experimental evidence, the review plays the role of unifying the separate pieces of evidence into a consistent evidence-based guide oriented toward clinical practice. This synthesis-based research innovatively offers valuable information that can lead to pilot clinical trials that aim to create new intervention models targeting oral microbiome examination and sugar management, and nutrient treatment protocols within dental healthcare systems.

Moreover, the review provides a basis to design further clinical intervention models, including individualized diet-based protocols in dentistry, microbiome-based treatment, and AI-assisted dietary assessment. This combination of insights in clinical education and in interprofessional pilot programs has the potential to affect future innovation in the fields of preventive dentistry, at least in underserved and high-risk communities. In future studies, researchers should examine the potential to incorporate AI-assisted dietary assessments and microbiome characterization into the recurring dental visit to create a link between nutritional counseling and personal prevention care.

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Appendix

Table A1: PRISMA 2020 checklist: completed.
Section and Topic	Item #	Checklist Item	Location Where Item Is Reported
TITLE	1	Identify the report as a systematic review.	Page 1 (Title and Abstract)
ABSTRACT	2	See the PRISMA 2020 for Abstracts checklist.	Page 1 (Structured Abstract)
INTRODUCTION	3	Describe the rationale for the review in the context of existing knowledge.	Pages 2–3 (Introduction)
INTRODUCTION	4	Provide an explicit statement of the objective(s) or question(s) the review addresses.	Page 3 (Objectives)
METHODS	5	Specify the inclusion and exclusion criteria for the review and how studies were grouped for the syntheses.	Page 5 (Inclusion & Exclusion Criteria)
METHODS	6	Specify all databases, registers, websites, organizations, reference lists, and other sources searched or consulted to identify studies. Specify the date when each source was last searched or consulted.	Pages 3–4 (Data Source and Search Strategy)
METHODS	7	Present the full search strategies for all databases, registers, and websites, including any filters and limits used.	Pages 3–4 (Search Strategy)
METHODS	8	Specify the methods used to decide whether a study met the inclusion criteria of the review, including how many reviewers screened each record and each report retrieved, whether they worked independently, and if applicable, details of automation tools used in the process.	Page 4 (Selection Criteria)
METHODS	9	Specify the methods used to collect data from reports, including how many reviewers collected data from each report, whether they worked independently, and any processes for obtaining or confirming data from study investigators.	Page 4 (Data Extraction and Analysis)
METHODS	10a	List and define all outcomes for which data were sought.	Page 4 (Data Extraction and Analysis)
METHODS	10b	List and define all other variables for which data were sought.	Page 4 (Data Extraction and Analysis)
METHODS	11	Specify the methods used to assess risk of bias in the included studies.	Page 4
METHODS	12	Specify for each outcome the effect measure(s).	Not applicable (Qualitative Synthesis only)
METHODS	13a	Describe the processes used to decide which studies were eligible for each synthesis.	Page 4 (Data Extraction and Analysis)
METHODS	13b	Describe any methods required to prepare the data for presentation or synthesis.	Page 4 (Data Extraction and Analysis)
METHODS	13c	Describe any methods used to tabulate or visually display results.	Page 4 (Table 1)
METHODS	13d	Describe any methods used to synthesize results and provide a rationale.	Page 5 (Data Synthesis)
METHODS	13e	Describe any methods used to explore possible causes of heterogeneity among study results.	Not conducted
METHODS	13f	Describe any sensitivity analyses conducted to assess robustness.	Not conducted
METHODS	14	Describe any methods used to assess risk of bias due to missing results.	JBI
METHODS	15	Describe any methods used to assess certainty.	Not assessed
RESULTS	16a	Describe the results of the search and selection process.	Page 5 (PRISMA Flow Diagram, Figure 4)
RESULTS	16b	Cite studies that might appear to meet inclusion criteria but were excluded.	Page 5 (PRISMA Flow Diagram)
RESULTS	17	Cite each included study and present its characteristics.	Page 4 (Table 1)
RESULTS	18	Present assessments of risk of bias for each included study.	JBI tool
RESULTS	19	For all outcomes, present summary statistics and estimates.	Pages 5–6 (Results)
RESULTS	20a	Summarize characteristics and risk of bias among contributing studies.	Page 6 (Outcomes of the Study)
RESULTS	20b	Present results of statistical syntheses conducted.	Not applicable (no meta-analysis)
RESULTS	20c	Present results of investigations of heterogeneity.	Not conducted
RESULTS	20d	Present results of sensitivity analyses.	Not conducted
RESULTS	21	Present assessments of risk of bias due to missing results.	Not assessed
RESULTS	22	Present assessments of certainty in the body of evidence.	Not assessed
DISCUSSION	23a	Provide a general interpretation of the results in the context of other evidence.	Pages 7–10 (Discussion)
DISCUSSION	23b	Discuss any limitations of the evidence included in the review.	Pages 7–10 (Limitations)
DISCUSSION	23c	Discuss any limitations of the review processes used.	Pages 7–10 (Limitations)
DISCUSSION	23d	Discuss implications for practice, policy, and future research.	Page 10 (Conclusion)
OTHER INFORMATION	24a	Provide registration information or state that it was not registered.	Not registered
OTHER INFORMATION	24b	Indicate where the review protocol can be accessed or state no protocol was prepared.	No protocol prepared
OTHER INFORMATION	24c	Describe and explain any amendments.	No amendments made
OTHER INFORMATION	25	Describe sources of financial or nonfinancial support.	Not reported
OTHER INFORMATION	26	Declare any competing interests of review authors.	Not reported
OTHER INFORMATION	27	Report which data, code, and materials are publicly available and where.	Not reported

Cite this article as:
Jamil M. The Impact of Diet on Oral Health: A Systematic Review. Premier Journal of Dentistry 2025;4:100006

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