IntroductionThe strength of the association between obesity and oral health is still indecisive.ObjectiveThe objectives of the study were to compare some oral‐health data between two groups involving obese (OG) and normal weight (NWG) participants and determine the influencing factors of the periodontal probing depth (PPD).MethodsThis was a cross‐sectional study including 67 Tunisian adults [OG (n = 33, body mass index (BMI) > 30 kg/m2), NWG (n = 34, BMI: 18.5–25.0 kg/m2)]. The plaque level was recorded using the plaque index (PI). Gingival index (GI) was used to evaluate gingival inflammation. The depths of the sulci/pockets were probed using a periodontal probe. Stimulated saliva was collected for 5 min, and salivary flow rate (SFR) was determined. Salivary baseline pH (SBpH) was measured. A multivariable regression analysis was performed between PPD and some independent variables [i.e. obesity status, age, sex, socioeconomic status, systemic diseases and PI data].ResultsThe OG and NWG were age‐ and sex‐matched and included comparable percentages of participants with systemic diseases (27.3 vs. 29.4%, respectively). The OG included a higher percentage of participants having a low socioeconomic status (87.9 vs. 64.7%, respectively). Compared with the NWG, the OG: (i) had comparable values of daily toothbrushing frequency, PI, GI and tooth mobility, (ii) included comparable percentages of irregular brushers, of participants with periodontitis, PI classes [0–1]and [1–2]; and GI classes [0–1], [1–2] and [2, 3]; (iii) had a higher PPD (2.02 ± 0.41 vs. 2.35 ± 0.22 mm, respectively), (iv) had lower SBpH (7.59 ± 0.21 vs. 7.45 ± 0.22, respectively) and SFR (1.98 ± 0.28 vs. 1.60 ± 0.32 mL/mn, respectively) and (v) included a higher percentage of participants having a PI class [2, 3] (67.6 vs. 87.9%, respectively). The multivariable regression analysis revealed that only obesity status, age and PI classes influenced the PPD, altogether explained 29.62% of the PPD variance.ConclusionObesity poses a risk for oral health, and obese adults had altered PPD and lower BSpH and SFR. Dentists should make obese patients aware of the health risks of obesity in an attempt to reduce the potential oral complications associated with this epidemic.